Loading systems for patient transport apparatuses

Abstract

A loading system for loading a patient transport apparatus into a transport vehicle. The patient transport apparatus includes a motor and a movable track powered by the motor. The loading system includes a loading device configured to engage the patient transport apparatus for lifting the patient transport apparatus into the transport vehicle. The loading device includes a frame and a traction roller arranged for operative engagement with the movable track of the patient transport apparatus for rotating the traction roller. The loading device further includes an elevating mechanism coupled between the frame and the transport vehicle, the elevating mechanism including an actuator interface disposed in rotational communication with the traction roller and being configured to move the patient transport apparatus between a lowered position and a raised position with torque generated by the motor of the patient transport apparatus.

Description

LOADING SYSTEMS FOR PATIENT TRANSPORT APPARATUSESCROSS-REFERENCE TO RELATED APPLICATION(S)

[0001] The subject patent application claims priority to and all the benefits of United States Provisional Patent Application No. 63 / 462,288 filed on April 27, 2023, the disclosure of which is hereby incorporated by reference in its entirety.BACKGROUND

[0002] In various environments, persons with limited mobility may have difficulty traversing stairs without assistance. In certain emergency situations, traversing stairs may be the only viable option for exiting a building. Here, in order for a caregiver to transport a patient along stairs in a safe and controlled manner, a stair chair or evacuation chair may be utilized to facilitate safe stair traversal. Stair chairs are adapted to transport seated patients either up or down flights of stairs, with two caregivers typically supporting, stabilizing, or otherwise carrying the stair chair with the patient supported thereon. The stair chair may be powered and include a battery and an electric motor, which further aids the caregiver when transporting heavy patients or on steeply inclined stairs.

[0003] The stair chair is generally transported inside an ambulance to the location of a patient. Within the ambulance, space is limited. Tightly packing all of the tools and supplies carried by an ambulance negatively impacts the time required to retrieve an item. An ambulance may have one or more exterior storage compartments that can be used to efficiently store that are only needed once the ambulance has arrived at the location of the patient. A loading system that overcomes the difficulty of loading a stair chair in a storage compailment with limited space is desirable.SUMMARY

[0004] The present disclosure provides a loading system for use with a transport vehicle, the loading system may include: a patient transport apparatus may include: a support structure, a seat section and a back section operatively attached to the support structure for supporting a patient during transport, a track assembly operatively attached to the support structure and including a movable belt for engaging stairs, where the track assembly is arranged for selective operation between a retracted position and a deployed position where the track assembly is arranged to engage stairs, and where the patient transport apparatus is operable between: a chair configuration where the track assembly is in the retracted position for supporting the patient transport apparatusfor movement along floor surfaces, a stair configuration where the track assembly is in the deployed position for supporting the patient transport apparatus for movement along stairs, and a stowed configuration, a motor coupled to the support structure and operably coupled to the track assembly for operating the movable belt, and a battery coupled to the support structure and in electrical communication with the motor; and a loading device configured to engage the support structure in the stowed configuration for lifting the patient transport apparatus from a lowered position to a raised position for loading into the transport vehicle, the loading device may include: a frame engageable with the patient transport apparatus for supporting the patient transport apparatus during loading into the transport vehicle, a traction roller rotatably supported by the frame and arranged for operative engagement with the movable belt of the track assembly of the patient transport apparatus, and an elevating mechanism operably coupled between the frame of the loading device and the transport vehicle, the elevating mechanism including an actuator interface disposed in rotational communication with the traction roller and being configured to move the patient transport apparatus between the lowered position and the raised position with torque generated by the motor of the patient transport apparatus.

[0005] The present disclosure also provides loading system for use with a transport vehicle, the loading system may include: a patient transport apparatus may include: a support structure having a seat section and being movable between a chair configuration and a stowed configuration, a motor coupled to the support structure, a battery coupled to the support structure and in electrical communication with the motor, and a drive element coupled to the support structure and operably coupled to the motor for powered operation, where the drive element is moveable between a retracted position and a deployed position; and a loading device configured to engage the support structure in the stowed configuration for lifting the patient transport apparatus from a lowered position to a raised position for loading into the transport vehicle, the loading device may include: a frame engageable with the patient transport apparatus for supporting the patient transport apparatus during loading into the transport vehicle, a traction roller rotatably supported by the frame and arranged for operative engagement with the drive element of the patient transport apparatus, and an elevating mechanism operably coupled between the frame of the loading device and the transport vehicle, the elevating mechanism including an actuator interface disposed in rotational communication with the traction roller and being configured to move the patienttransport apparatus between the lowered position and the raised position with torque generated by the motor of the patient transport apparatus.

[0006] Any of the above aspects can be combined in full or in part. Any features of the above aspects can be combined in full or in part. Any of the above implementations for any aspect can be combined with any other aspect. Any of the above implementations can be combined with any other implementation whether for the same aspect or a different aspect. This summary introduces a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to limit the scope of the claimed subject matter nor identify key features or essential features of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Advantages of the present disclosure will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings.

[0008] Figure 1 is an environmental view of a transport vehicle having a first cargo area including a loading system for loading a powered patient transport apparatus into the first cargo area.

[0009] Figure 2 is an environmental view of the transport vehicle having a second cargo area including the loading system for loading the powered patient transport apparatus into the second cargo area with the loading system shown in a lowered position.

[0010] Figure 3A is an environmental view of the transport vehicle and loading system of Figure 2 shown with the loading system in a lowered position.

[0011] Figure 3B is another environmental view of the transport vehicle and loading system of Figure 3A shown with the loading system in a raised position.

[0012] Figure 4 is a front perspective view of the powered patient transport apparatus of Figures 1-3B, shown arranged in a stair configuration for supporting a patient for transport along stairs, and shown with a track assembly disposed in a deployed position, and with a handle assembly disposed in an extended position.

[0013] Figure 5 is another front perspective view of the powered patient transport apparatus of Figure 4, shown arranged in a chair configuration for supporting a patient for transport along a floor surface, and shown with a track assembly disposed in a retracted position, and with a handle assembly disposed in a collapsed position.

[0014] Figure 6 is a rear perspective view of the powered patient transport apparatus of Figures 4 and 5, shown arranged in the stair configuration as depicted in Figure 4, and shown having an extension lock mechanism, a folding lock mechanism, and a deployment lock mechanism.

[0015] Figure 7 is a partial schematic view of a control system of the powered patient transport apparatus of Figures 4-6, shown with a controller disposed in communication with a battery, a user interface, and a drive system.

[0016] Figure 8 is a right-side plan view of the powered patient transport apparatus of Figures 4-7, shown arranged in a stowed configuration maintained by the folding lock mechanism.

[0017] Figure 9 A is another right-side plan view of the powered patient transport apparatus arranged in the chair configuration and with the handle assembly in a collapsed position.

[0018] Figure 9B is another right-side plan view of the powered patient transport apparatus arranged in the stair configuration and with the handle assembly in an intermediate position.

[0019] Figure 9C is another right-side plan view of the powered patient transport apparatus arranged in the stair configuration and with the handle assembly in an extended position.

[0020] Figure 10A is a partial rear perspective view of the powered patient transport apparatus of Figures 4-9C, shown arranged in the stowed configuration as depicted in Figure 3B, with the deployment lock mechanism shown retaining the track assembly in the retracted position.

[0021] Figure 10B is another partial rear perspective view of the powered patient transport apparatus of Figure 10A, shown arranged in the stowed configuration, with the deployment lock mechanism shown retaining the track assembly in the deployed position.

[0022] Figure 11 is a rear view of the back side of the powered patient transport apparatus of Figure 3B depicting the user interface.

[0023] Figure 12A is a right-side plan view of the powered patient transport apparatus of Figure 3B, shown supporting a patient in the chair configuration on a floor surface adjacent to stairs, and shown with a first caregiver engaging a pivoting handle assembly.

[0024] Figure 12B is another right-side plan view of the powered patient transport apparatus of Figure 12A, shown with the first caregiver having engaged the deployment lock mechanism to move the track assembly out of the retracted position and a second caregiver engaging a front handle assembly in an extended position.

[0025] Figure 12C is another right-side plan view of the powered patient transport apparatus of Figure 12B, shown having moved towards the stairs for descent while supported by the first and second caregivers.

[0026] Figure 12D is another right-side plan view of the powered patient transport apparatus of Figure 12C, shown having moved initially down the stairs for descent to bring a belt of the track assembly into contact with the stairs while still supported by the first and second caregivers.

[0027] Figure 12E is another right-side plan view of the powered patient transport apparatus of Figure 12D, shown with the belt of the track assembly in contact with the stairs while still supported by the first and second caregivers.

[0028] Figure 12F is another right-side plan view of the powered patient transport apparatus of Figure 12E, shown with the belt of the track assembly in contact with the stairs while still supported by the first and second caregivers.

[0029] Figure 13 is a close-up perspective view of the transport vehicle and cargo area of Figure 1 showing a boom, the loading system, and a brace coupled to the boom.

[0030] Figure 14 is a side view of the powered patient transport apparatus and the loading system, shown with a loading device in a decoupled configuration.

[0031] Figure 15 is a cross-sectional view of the powered patient transport apparatus and the loading system of Figure 14, shown with the loading device in a partially coupled configuration.

[0032] Figure 16 is a side view of the powered patient transport apparatus and the loading system of Figure 14, shown with the loading system in a raised position and coupled to a transport vehicle and with the loading device coupled to the powered patient transport apparatus.

[0033] Figure 17 is a rear perspective view of the powered patient transport apparatus coupled to the loading device.

[0034] Figure 18 is a close-up perspective view of the powered patient transport apparatus and the loading device of Figure 17 in a lowered position and showing a latch, a frame, a flexible tensioning element, and a tension assembly.

[0035] Figure 19 is another close-up perspective view of the powered patient transport apparatus and the loading device of Figure 17 in a raised position.

[0036] Figure 20 is a perspective view of the loading device shown having the frame and the tension assembly.

[0037] Figure 21 is an exploded view of the loading device of Figure 20 showing the frame, the tension assembly, and traction rollers.

[0038] Figure 22 is a perspective view of a first alternative implementation of the loading device shown having the frame, the tension assembly, and a resistance mechanism.

[0039] Figure 23 is a perspective view of a second alternative implementation of the loading device shown having the frame having a pivoting connection and the tension assembly.

[0040] Figure 24A is a perspective view depicting another version of a loading system shown with a loading device supporting a patient transport apparatus in a lowered position.

[0041] Figure 24B is another perspective view of the loading system of Figure 24A shown with the loading device supporting the patient transport apparatus in a raised position.

[0042] Figure 25 is a perspective view of the loading device of Figures 24A-24B.

[0043] Figure 26 is another perspective view of the loading device of Figure 25.DETAILED DESCRIPTION

[0044] Referring now to the drawings, wherein like numerals indicate like parts throughout the several views, the present disclosure is directed toward a loading system 400, which generally includes a patient transport apparatus 100 configured to allow one or more caregivers to transport a patient, and a loading device 404 to load the patient transport apparatus 100 into and unload the patient transport apparatus from a transport vehicle 50 (e.g., an ambulance) for storage and transport, as described in greater detail below.

[0045] The patient transport apparatus 100 is realized as a “stair chair”, which can be operated in a chair configuration CC (see Figure 5) to transport the patient across ground or floor surfaces FS (e.g., pavement, hallways, and the like), a stair configuration SC (see Figure 4) to transport the patient along stairs ST, and a stowed (or folded) configuration FC (see Figure 8) when not being utilized to transport patients. As will be appreciated from the subsequent description below, the patient transport apparatus 100 may be stored or otherwise transported in the transport vehicle 50 in the stowed configuration FC.

[0046] In Figure 1, a first exemplary transport vehicle 50 is shown as an ambulance. The transport vehicle generally comprises an interior volume 52 in which a patient and caregivers are located during use. The interior volume 52 may include a system for loading an ambulance cot (not shown) to aid caregivers in loading the patient and cot into the transport vehicle 50. In addition to the interior volume 52, the transport vehicle 50 may further comprise one or morestorage compartments 54 that define a corresponding cargo volume 56, which is accessible from an exterior of the transport vehicle 50 through a corresponding door 58. The storage compartments 54 facilitate quick and easy access to equipment that a caregiver may need to aid a patient. The cargo volume 56 of the storage compartment 54 may further be accessible from the interior volume 52 of the transport vehicle 50 in order to access the contents of the cargo volume 56 while the transport vehicle 50 is moving.

[0047] In addition to the aforementioned cot, caregivers may also utilize other patient transport apparatuses 100, such as the patient transport apparatus 100 illustrated throughout the drawings, which facilitates transporting a patient up and down a stairs ST. Generally, once the patient has reached the “ground floor” (i.e., the same as the transport vehicle) of a particular location and is otherwise accessible by a wheeled ambulance cot, the patient is transferred from the patient transport apparatus 100 to wheeled ambulance cot and loaded into the interior volume 52 of the transport vehicle 50. As such, the patient is generally not transported within the transport vehicle 50 while seated in the patient transport apparatus 100. Said differently, unlike an ambulance cot, the patient transport apparatus 100 is intended to be unoccupied when transported by the transport vehicle 50, and caregiver access to the patient transport apparatus 100 while the transport vehicle 50 is in motion is unnecessary. It is therefore beneficial to minimize the storage volume required to transport the patient transport apparatus 100 within the transport vehicle 50, which may likewise increase the difficulty of loading the patient transport apparatus 100 into the transport vehicle 50, particularly when the patient transport apparatus 100 is heavy or unwieldy.

[0048] To this end, the transport vehicle 50 and the loading system 400 may be used in combination to facilitate loading the patient transport apparatus 100. Because the patient transport apparatus 100 is not needed while the transport vehicle 50 is in motion, the patient transport apparatus 100 may advantageously be stored in one of the storage compartments 54 on the exterior of the transport vehicle 50. The loading system 400 may aid lifting the patient transport apparatus 100 into the associate cargo volume 56. Figure 1 illustrates a first such arrangement whereby the transport vehicle 50 has a first storage compartment 54A with the loading system 400 configured to lift the patient transport apparatus 100 for placement into the first cargo volume 56A. Figures 2-3B illustrate another arrangement of the transport vehicle having a second storage compartment 54B with the loading system 400 configured to lift the patient transport apparatus 100 for placement into the second cargo volume 56B.

[0049] As is best shown in Figure 5, the patient transport apparatus 100 comprises a support structure 102 to which a seat section 104 and a back section 106 are operatively attached. The seat section 104 and the back section 106 are each shaped and arranged to provide support to the patient during transport. The support structure 102 generally includes a rear support assembly 108, a front support assembly 110, and an intermediate support assembly 112. The back section 106 is coupled to the rear support assembly 108 for concurrent movement. To this end, the rear support assembly 108 comprises a first rear upright 114A arranged on a first side of the rear support assembly 108. The rear support assembly 108 may further comprise a second read upright 114B on a second side of the rear support assembly 108, opposite the first side. The rear uprights 114A, 114B may extend generally vertically and are secured to the back section 106 such as with fasteners (not shown in detail).

[0050] The intermediate support assembly 112 and the seat section 104 are each pivotably coupled to the rear support assembly 108. More specifically, the seat section 104 is arranged so as to pivot about a rear seat axis RS A which extends through the rear uprights 114A, 114B (compare Figures 8-9A; pivoting about rear seat axis RSA not shown in detail), and the intermediate arms 118 of the intermediate support assembly 112 are arranged so as to pivot about a rear arm axis RAA which is spaced from the rear seat axis RSA and also extends through the rear uprights 114A, 114B (compare Figures 8-9A; pivoting about rear arm axis RAA not shown in detail). Furthermore, the intermediate support assembly 112 and the seat section 104 are also each pivotably coupled to the front support assembly 110. Here, the seat section 104 pivots about a front seat axis FSA which extends through the front struts 116 (compare Figures 8-9A; pivoting about front seat axis FSA not shown in detail), and the intermediate arms 118 pivot about a front arm axis FAA which is spaced from the front seat axis FSA and extends through the front struts 116 (compare Figures 8-9A; pivoting about front arm axis FAA not shown in detail). The intermediate support assembly 112 is disposed generally vertically below the seat section 104 such that the rear support assembly 108, the front support assembly 110, the intermediate support assembly 112, and the seat section 104 generally define a four-bar linkage which helps facilitate movement between the stowed configuration FC (see Figure 8) and the chair configuration CC (see Figure 9A). While the seat section 104 is generally configured to remain stationary relative to the support structure 102 when operating in the chair configuration CC or in the stair configuration CC according to the illustrated versions, it is contemplated that the seat section 104could comprise multiple components which cooperate to facilitate “sliding” movement relative to the seat section 104 under certain operating conditions, such as to position the patient's center of gravity advantageously for transport. Other configurations are contemplated.

[0051] Referring now to Figures 4-6, the front support assembly 110 includes a pair of caster assemblies 120 which each comprise a front wheel 122 arranged to rotate about a respective front wheel axis FWA and to pivot about a respective swivel axis SA (compare Figures 8-9A; pivoting about swivel axis SA not shown in detail). The caster assemblies 120 are generally arranged on opposing lateral sides of the front support assembly 110 and are operatively attached to the front struts 116. A lateral brace 124 (see Figure 6) extends laterally between the front struts 116 to, among other things, afford rigidity to the support structure 102. Here, a foot rest 126 is pivotably coupled to each of the front struts 116 adjacent to the caster assemblies 120 (pivoting not shown in detail) to provide support to the patient's feet during transport. For each of the pivotable connections disclosed herein, it will be appreciated that one or more fasteners, bushings, bearings, washers, spacers, and the like may be provided to facilitate smooth pivoting motion between various components.

[0052] The representative versions of the patient transport apparatus 100 illustrated throughout the drawings comprise different handles arranged for engagement by caregivers during patient transport. More specifically, the patient transport apparatus 100 comprises front handle assemblies 128, pivoting handle assemblies 130, and an upper handle assembly 132 (hereinafter referred to as “handle assembly 132”), each of which will be described in greater detail below. The front handle assemblies 128 are supported within the respective intermediate arms 118 for movement between a collapsed position 128A (see Figure 12A) and an extended position 128B (see Figure 12B). To this end, the front handle assemblies 128 may be slidably supported by bushings, bearings, and the like (not shown) coupled to the intermediate arms 118, and may be lockable in and / or between the collapsed position 128A and the extended position 128B via respective front handle locks 134 (see Figure 5).

[0053] Here, a caregiver may engage the front handle locks 134 (not shown in detail) to facilitate moving the front handle assemblies 128 between the collapsed position 128A and the extended position 128B. The front handle assemblies 128 are generally arranged so as to be engaged by a caregiver during patient transport up or down stairs ST when in the extended position 128B. It will be appreciated that the front handle assemblies 128 could be of various types, styles,and / or configurations suitable to be engaged by caregivers to support the patient transport apparatus 100 for movement. While the illustrated front handle assemblies 128 are arranged for telescoping movement, other configurations are contemplated. By way of non-limiting example, the front handle assemblies 128 could be pivotably coupled to the support structure 102 or other parts of the patient transport apparatus 100. In some versions, the front handle assemblies 128 could be configured similar to as is disclosed in U.S. Patent No. 6,648,343, the disclosure of which is hereby incorporated by reference in its entirety.

[0054] The pivoting handle assemblies 130 are coupled to the respective rear uprights 114A, 114B of the rear support assembly 108, and are movable relative to the rear uprights 114A, 114B between a stowed position 130A and an engagement position 130B. Like the front handle assemblies 128, the pivoting handle assemblies 130 are generally arranged for engagement by a caregiver during patient transport, and may advantageously be utilized in the engagement position 130B when the patient transport apparatus 100 operates in the chair configuration CC to transport the patient along floor surfaces FS. In some versions, the pivoting handle assemblies 130 could be configured similar to as is disclosed in U.S. Patent No. 6,648,343, previously incorporated by reference. Other configurations are contemplated.

[0055] As is best depicted in Figure 9 A, the rear uprights 114A, 114B each generally extend between a lower upright end 115A and an upper upright end 115B, with the hub axis HA arranged adjacent to the lower upright end 115A. The lower upright end 115A is supported for movement within the hub 158, which may comprise a hollow profile or recess defined by multiple hub housing components. In the illustrated version, the hub axis HA is arranged generally vertically between the rear arm axis RAA and the wheel axis WA. The rear uprights 114A, 114B may each comprise a generally hollow, extruded profile which supports various components of the patient transport apparatus 100.

[0056] As best shown in Figure 5, the handle assembly 132 includes an upper grip 136. The upper grip 136 is operatively attached to a first extension post 138A. The first extension post 138A is disposed within the first rear upright 114A. Accordingly, the first extension post 138A supports the upper grip 136 for movement of the handle assembly 132 between a collapsed position 132A where the upper grip is disposed adjacent to the user interface (see Figure 5 and an extended position 132B where the upper grip is spaced from the user interface (see Figure 4). In some examples, the upper grip 136 may extend between a first upper grip end 136A and a second uppergrip end 136B. The first extension post 138 A may be operatively attached to the first upper grip end 136A. The handle assembly 132 may further include a second extension post 138B operatively attached to the second upper grip end 136B. Together, the first and second extension posts 138A, 138B may support the upper grip 136 for movement of the handle assembly 132 between the collapsed position 132A and the extended position 132B.

[0057] In the representative version illustrated herein, the upper grip 136 generally comprises a first hand grip region 144 arranged adjacent to the first extension posts 138A, and a second hand grip region 146 arranged adjacent to the second extension post 138B, each of which may be engaged by the caregiver to support the patient transport apparatus 100 for movement, such as during patient transport up or down stairs ST (see Figures 12A-12F). The activation input controls 214 may be arranged in various locations about the patient transport apparatus 100. In the illustrated versions, a first activation input control 222 is disposed adjacent to the first hand grip region 144 of the handle assembly 132, and a second activation input control 224 is disposed adjacent to the second hand grip region 146 (best shown in Figure 5). In the illustrated version, the user interface 204 is configured such that the caregiver can engage either of the activation input controls 222, 224 with a single hand grasping the upper grip 136 (described below) of the handle assembly 132 during use.

[0058] The activation input controls 214 may be arranged between the first and second hand grip regions 144, 146 in order to facilitate user engagement of the activation input controls 214 from either of the first and second hand grip regions 144, 146. As previously discussed, the activation input controls 214 include the first activation input control 222 and the second activation input control 224. The first activation input control 222 may be disposed adjacent the first hand grip region 144 so as to facilitate user engagement of the first activation input control 222 from the first hand grip region 144. The second activation input control 224 may be disposed adjacent to the second hand grip region 146 so as to facilitate user engagement of the second activation input control 224 from the second hand grip region 146. Here, it will be appreciated that the user can engage either of the first and second hang grip regions 144, 146 with one of their hands to support the patient transport apparatus 100 while, at the same, using that same hand to activate one of the first and second activation input controls 222, 224 (e.g., reaching with their thumb).

[0059] The first activation input control 222 and the second activation input control 224 may be spaced apart by a predetermined distance (e.g., several inches) and are wired in parallel in some versions (not shown in detail).

[0060] Referring to Figures 9A-9C, the handle assembly 132 is configured for movement between the extended position 132B (shown in Figure 9A) where the upper grip 136 is spaced from the user interface 204 at a first distance DI, and the collapsed position 132A (shown in Figure 9C) where the upper grip 136 is disposed adjacent to the user interface 204. Additionally, the handle assembly 132 may be configured for movement to an intermediate position 132C (shown in Figure 9B) where the upper grip 136 is spaced from the user interface 204 at a second distance D2, less than the first distance DI.

[0061] As noted above, the patient transport apparatus 100 is configured for use in transporting the patient across floor surfaces FS, such as when operating in the stair configuration SC, and for transporting the patient along stairs ST when operating in the stair configuration SC. To these ends, the illustrated patient transport apparatus 100 includes a carrier assembly 148 arranged for movement relative to the support structure 102 between the chair configuration CC and the stair configuration ST. The carrier assembly 148 generally comprises at least one shaft 150 defining a wheel axis WA, one or more rear wheels 152 supported for rotation about the wheel axis WA, at least one track assembly 154 having a belt 156 for engaging stairs ST, and one or more hubs 158 supporting the shaft 150 and the track assembly 154 and the shaft 150 for concurrent pivoting movement about a hub axis HA. Here, movement of the carrier assembly 148 from the chair configuration CC (see Figure 5) to the stair configuration SC (see Figures 4 and 9B) simultaneously deploys the track assembly 154 for engaging stairs ST with the belt 156 and moves the wheel axis WA longitudinally closer to the front support assembly 110 so as to position the rear wheels 152 further underneath the seat section 104 and closer to the front wheels 122.

[0062] As is described in greater detail below in connection with Figures 12A-12F, the movement of the rear wheels 152 relative to the front wheels 122 when transitioning from the chair configuration CC to the stair configuration SC that is afforded by the patient transport apparatus 100 of the present disclosure affords significant improvements in patient comfort and caregiver usability, in that the rear wheels 152 are arranged to promote stable transport across floor surfaces FS in the chair configuration CC but are arranged to promote easy transitioning from floor surfaces to stairs ST as the patient transport apparatus 100 is “tilted” backwards about the rear wheels 152(compare Figures 12D-12F). Put differently, positioning the real- wheels 152 relative to the front wheels 122 consistent with the present disclosure makes “tilting” the patient transport apparatus 100 significantly less burdensome for the caregivers and, at the same time, much more comfortable for the patient due to the arrangement of the patient’s center of gravity relative to the portion of the rear wheels 152 contacting the floor surface FS as the patient transport apparatus 100 is “tilted” backwards to transition into engagement with the stairs ST.

[0063] In the representative versions illustrated herein, the carrier assembly 148 comprises hubs 158 that are pivotably coupled to the respective rear uprights 114A, 114B for concurrent movement about the hub axis HA. Here, one or more bearings, bushings, shafts, fasteners, and the like (not shown in detail) may be provided to facilitate pivoting motion of the hubs 158 relative to the rear uprights 114A, 114B. Similarly, bearings and / or bushings (not shown) may be provided to facilitate smooth rotation of the rear wheels 152 about the wheel axis WA. Here, the shafts 150 may be fixed to the hubs 158 such that the rear wheels 152 rotate about the shafts 150 (e.g., about bearings supported in the rear wheels 152), or the shafts 150 could be supported for rotation relative to the hubs 158. Each of the real- wheels 152 is also provided with a wheel lock 160 coupled to its respective hub 158 to facilitate inhibiting rotation about the wheel axis WA. The wheel locks 160 are generally pivotable relative to the hubs 158, and may be configured in a number of different ways without departing from the scope of the present disclosure. While the representative version of the patient transport apparatus 100 illustrated herein employs hubs 158 with “mirrored” profiles that are coupled to the respective rear uprights 114A, 114B and support discrete shafts 150 and wheel locks 160, it will be appreciated that a single hub 158 and / or a single shaft 150 could be employed. Other configurations are contemplated.

[0064] Referring now to Figures 10A-10B, as noted above, the track assemblies 154 move concurrently with the hubs 158 between the chair configuration CC and the stair configuration SC. Here, the track assemblies 154 are arranged in a retracted position 154A when the carrier assembly 148 is disposed in the chair configuration CC, and are disposed in a deployed position 154B when the carrier assembly 148 is disposed in the stair configuration SC. As is described in greater detail below, the illustrated patient transport apparatus 100 comprises a deployment linkage 162 and a deployment lock mechanism 164 with a deployment lock release 166 arranged for engagement by the caregiver to facilitate changing between the retracted position 154A and the deployed position 154B (and, thus, between the chair configuration CC and the stair configuration SC).

[0065] In the illustrated version, the patient transport apparatus 100 comprises laterally-spaced track assemblies 154 each having a single belt 156 arranged to contact stairs ST. However, it will be appreciated that other configurations are contemplated, and a single track assembly 154 and / or track assemblies with multiple belts 156 could be employed. The track assemblies 154 each generally comprise a rail 168 extending between a first rail end 168 A and a second rail end 168B. The second rail end 168B is operatively attached to the hub 158, such as with one or more fasteners (not shown in detail). An axle 170 defining a roller axis RA is disposed adjacent to the first rail end 168A of each rail 168, and a roller 172 is supported for rotation about the roller axis RA. For each of the track assemblies 154, the belt 156 is disposed in engagement with the roller 172 and is arranged for movement relative to the rail 168 in response to rotation of the roller 172 about the roller axis RA.

[0066] The track assemblies 154 may further comprise a cross brace 173 extending laterally therebetween. The cross brace 173 is coupled to the rail 168 of each track assembly 154 to effect coordinated motion of the track assemblies 154. Said differently, movement of one of the track assemblies 154 between the retracted position 154A and the deployed position 154B causes corresponding movement of the other track assembly 154. The cross brace 173 may further provide increased resistance to deflection of the track assemblies 154 when subjected to lateral loads near the first rail end 168 A by transferring force exerted on one track assembly 154 to the other track assembly 154. The cross brace 173 may be coupled to the rails 168 with threaded fasteners or may be permanently coupled to the rails 168 by way of a welding process.

[0067] Adjacent to the second rail end 168B of each rail 168, a drive pulley 174 is supported for rotation about a drive axis DA and is likewise disposed in engagement with the belt 156 (see Figures 10A-10B; rotation about drive axis DA not shown in detail). Here, the drive pulley 174 comprises outer teeth 176 which are disposed in engagement with inner teeth 178 formed on the belt 156. The track assemblies 154 each also comprise a belt tensioner, generally indicated at 180, configured to adjust tension in the belt 156 between the roller 172 and the drive pulley 174.

[0068] In the representative version illustrated herein, the patient transport apparatus 100 comprises a drive system, generally indicated at 182, configured to facilitate driving the belts 156 of the track assemblies 154 relative to the rails 168 to facilitate movement of the patient transport apparatus 100 up and down stairs ST. To this end, and as is depicted in Figure 10A, the drive system 182 comprises a drive frame 184 and a cover 186 which are operatively attached to thehubs 158 of the carrier assembly 148 for concurrent movement with the track assemblies 154 between the retracted position 154A and the deployed position 154B. A motor 188 (depicted in phantom in Figure 10A) is coupled to the drive frame 184 and is concealed by the cover 186. The motor 188 is configured to selectively generate rotational torque used to drive the belts 156 via the drive pulleys 174, as described in greater detail below. To this end, a drive axle 190 is coupled to each of the drive pulleys 174 and extends along the drive axis DA laterally between the track assemblies 154. The drive axle 190 is rotatably supported by the drive frame 184, such as by one or more bearings, bushings, and the like (not shown in detail). A geartrain 192 is disposed in rotational communication between the motor 188 and the drive axle 190. To this end, in the version depicted in Figure 10A, the geartrain 192 comprises a first sprocket 194, a second sprocket 196, and an endless chain 198. Here, the motor 188 comprises an output shaft 200 to which the first sprocket 194 is coupled, and the second sprocket 196 is coupled to the drive axle 190. The endless chain 198, in turn, is supported about the first sprocket 194 and the second sprocket 196 such that the drive axle 190 and the output shaft 200 rotate concurrently. The geartrain 192 may be configured so as to adjust the rotational speed and / or torque of the drive axle 190 relative to the output shaft 200 of the motor, such as by employing differently-configured first and second sprockets 194, 196 (e.g., different diameters, different numbers of teeth, and the like).

[0069] While the representative version of the drive system 182 illustrated herein utilizes a single motor 188 to drive the belts 156 of the track assemblies 154 concurrently using a chainbased geartrain 192, it will be appreciated that other configurations are contemplated. By way of non-limiting example, multiple motors 188 could be employed, such as to facilitate driving the belts 156 of the track assemblies 154 independently. Furthermore, different types of geartrains 192 are contemplated by the present disclosure, including without limitation the geartrains 192 which comprise various arrangements of gears, planetary gearsets, and the like.

[0070] The patient transport apparatus 100 comprises a control system 202 to, among other things, facilitate control of the track assemblies 154. To this end, and as is depicted schematically in Figure 7, the representative version of the control system 202 generally comprises a user interface 204, a battery 206, one or more sensors 208, and one or more back light modules 210 which are disposed in electrical communication with a controller 212. As will be appreciated from the subsequent description below, the controller 212 may be of a number of different types, styles, and / or configurations, and may employ one or more microprocessors for processing instructionsor an algorithm stored in memory to control operation of the motor 188, the light modules 210, and the like. Additionally or alternatively, the controller 212 may comprise one or more subcontrollers, microcontrollers, field programmable gate arrays, systems on a chip, discrete circuitry, and / or other suitable hardware, software, and / or firmware that is capable of carrying out the functions described herein.

[0071] The controller 212 is coupled to various electrical components of the patient transport apparatus 100 (e.g., the motor 188) in a manner that allows the controller 212 to control or otherwise interact with those electrical components the (e.g., via wired and / or wireless electrical communication). In some versions, the controller 212 may generate and transmit control signals to the one or more powered devices, or components thereof, to drive or otherwise facilitate operating those powered devices, or to cause the one or more powered devices to perform one or more of their respective functions.

[0072] The controller 212 may utilize various types of sensors 208 of the control system 202, including without limitation force sensors (e.g., load cells), timers, switches, optical sensors, electromagnetic sensors, motion sensors, accelerometers, potentiometers, infrared sensors, ultrasonic sensors, mechanical limit switches, membrane switches, encoders, and / or cameras. One or more sensors 208 may be used to detect mechanical, electrical, and / or electromagnetic coupling between components of the patient transport apparatus 100. Other types of sensors 208 are also contemplated. Some of the sensors 208 may monitor thresholds movement relative to discrete reference points. The sensors 208 can be located anywhere on the patient transport apparatus 100, or remote from the patient transport apparatus 100. Other configurations are contemplated.

[0073] The battery 206 provides power to the controller 212, the motor 188, the light modules 210, and other components of the patient transport apparatus 100 during use, and is removably attachable to the cover 186 of the drive system 182 in the illustrated version (see Figure 10A; attachment not shown in detail). The user interface 204 is generally configured to facilitate controlling the drive direction and drive speed of the motor 188 to move the belts 156 of the track assembly 154 and, thus, allow the patient transport apparatus 100 to ascend or descend stairs ST. Here, the user interface 204 may comprise one or more activation input controls 214 to facilitate driving the motor 188 in response to engagement by the caregiver, one or more direction input controls 216 to facilitate changing the drive direction of the motor 188 in response to engagement by the caregiver, and / or one or more speed input controls 218 to facilitate operating the motor 188at different predetermined speeds selectable by the caregiver. The one or more direction input controls 216 and the one or more speed input controls 218 may be coupled to the real' support assembly 108 and referred to as lower input controls 219. The user interface 204 may also comprise various types of indicators 220 to display information to the caregiver. It will be appreciated that the various components of the control system 202 introduced above could be configured and / or arranged in a number of different ways, and could communicate with each other via one or more types of electrical communication facilitated by wired and / or wireless connections. Other configurations are contemplated.

[0074] In the illustrated versions, the patient transport apparatus 100 is configured to limit movement of the belts 156 relative to the rails 168 during transport along stairs ST in an absence of engagement with the activation input controls 214 by the caregiver. Put differently, one or more of the controller 212, the motor 188, the geartrain 192, and / or the track assemblies 154 may be configured to “brake” or otherwise prevent movement of the belts 156 unless the activation input controls 214 are engaged. To this end, the motor 188 may be controlled via the controller 212 to prevent rotation (e.g., driving with a 0% pulse-width modulation PWM signal) in some versions. However, other configurations are contemplated, and the patient transport apparatus 100 could be configured to prevent movement of the belts 156 in other ways. By way of non-limiting example, a mechanical brake system (not shown) could be employed in some versions.

[0075] Referring now to Figure 10A, the patient transport apparatus 100 employs the deployment lock mechanism 164 to releasably secure the track assembly 154 in the retracted position 154A and in the deployed position 154B. The deployment lock release 166 is arranged for engagement by the caregiver to move between the retracted position 154A and the deployed position 154B. The deployment lock mechanism 164 is coupled to the track assemblies 154 for concurrent movement, and the deployment linkage 162 is coupled between the deployment lock mechanism 164 and the support structure 102. The illustrated deployment linkage 162 generally comprises connecting links 226 which are pivotably coupled to the support structure 102, and brace links 228 which are coupled to the deployment lock mechanism 164 and are respectively pivotably coupled to the connecting links 226.

[0076] The connecting links 226 each comprise or otherwise define a forward pivot region 230, a connecting pivot region 232, a trunnion region 234, and an interface region 236. The forward pivot regions 230 extend from the interface regions 236 to forward pivot mounts 238which are pivotably coupled to the rear uprights 114A, 114B about the rear seat axis RSA, such as by one or more fasteners, bushings, bearings, and the like (not shown in detail). Here, because the rear uprights 114A, 114B are spaced laterally away from each other at a distance large enough to allow the track assemblies 154 to “nest” therebetween in the retracted position 154A (see Figure 10A), the forward pivot regions 230 of the connecting links 226 extend at an angle away from the rear uprights 114A, 114B at least partially laterally towards the track assemblies 154.

[0077] The trunnion regions 234 extend generally vertically downwardly from the interface regions 236 to trunnion mount ends 240, and comprise trunnions 242 which extend generally laterally and are arranged to abut trunnion catches 244 of the deployment lock mechanism 164 to retain the track assemblies 154 in the retracted position 154A (see Figure 10A). The connecting pivot regions 232 extend longitudinally away from the interface regions 236 to rearward pivot mounts 246 which pivotably couple to the brace links 228 about a link axis LA. The connecting links 226 are each formed as separate components with mirrored profiles in the illustrated versions, but could be realized in other ways, with any suitable number of components.

[0078] The brace links 228 each generally extend between an abutment link end 250 and a rearward link mount 252, with a forward link mount 254 arranged therebetween. The forward link mounts 254 are pivotably coupled to the rearward pivot mounts 246 of the connecting links 226 about the link axis LA, such as by one or more fasteners, bushings, bearings, and the like (not shown in detail). The rearward link mounts 252 are each operatively attached to the deployment lock mechanism 164 about a barrel axis BA. The brace links 228 each define a link abutment surface 256 disposed adjacent to the abutment link end 250 which are arranged to abut the link stops 248 of the connecting links 226 in the deployed position 154B (see Figure 10B). The brace links 228 also define a relief region 258 formed between the forward link mount 254 and the rearward link mount 252. The relief regions 258 are shaped to at least partially accommodate the link stops 248 of the connecting links 226 when the track assemblies 154 are in the retracted position 154A (not shown in detail). The deployment linkage 162, the deployment lock mechanism 164, and the deployment lock release 166 may be similar to as is disclosed by U.S. Patent Publication No. 2021 / 0196536, the disclosure of which is hereby incorporated by reference in its entirety.

[0079] With continued reference to Figures 10A-10B and additional reference to Figure 11, the patient transport apparatus 100 employs a folding lock mechanism 284 to facilitate changingbetween the stowed configuration FC (see Figure 8) and the chair configuration CC (see Figure 9A). To this end, the folding lock mechanism 284 generally comprises a folding lock release 286 operatively attached to the back section 106 and arranged for engagement by the caregiver to releasably secure the folding lock mechanism 284 between a stow lock configuration to maintain the stowed configuration FC, and a use lock configuration to prevent movement to the stowed configuration FC from the chair configuration CC or from the stair configuration SC. The folding lock mechanism 284 may incorporate features as disclosed in U.S. Patent No. 6,648,343 previously incorporated by reference and as disclosed in U.S. Patent Publication No. 2021 / 0196536, previously incorporated by reference.

[0080] The drive system 182 may include various components not specifically illustrated or be configured in various ways not discussed in detail but described in U.S. Patent Publication No. 2021 / 0196536, previously referenced and incorporated by reference. In a version, the motor 188 may be supported on an adjustable platform that is movable relative to the drive frame 184 to adjust slack in the endless chain. This arrangement helps to optimize power density and minimize weight in the drive system 182. It will be appreciated that this arrangement could be utilized with other types of geartrains 192, such as where a belt drive (not shown) would replace the endless chain 198. Other configurations are contemplated.

[0081] In some versions, the geartrain 192 may be configured with a direct drive gearbox coupled to one of the rails 168 of the track assembly 154. Here, the drive axle 190 extends through the direct drive gearbox, and the motor 188 may be coupled to the direct drive gearbox. In some versions, the patient transport apparatus 100 may include a “passive brake” that allows the speed of the patient transport apparatus 100 to be controlled when on stairs ST even when the battery 206 is of low charge, dead, or not connected to the drive system 182 (e.g., inadvertently removed).

[0082] Figures 12A-12F successively depict exemplary steps of transporting a patient supported on the patient transport apparatus 100 down the stairs ST. In Figure 12A, a first caregiver is shown engaging the pivoting handle assemblies 130 in the engagement position 130B to illustrate approaching stairs ST while the patient transport apparatus 100 is moved along floor surfaces FS in the chair configuration CC. In Figure 12B, the patient transport apparatus 100 has been moved closer to the stairs with a second caregiver engaging the front handle assemblies 128 after having moved them to the extended position 128B. The deployment lock release 166 was also deployed by the first caregiver to move the patient transport apparatus 100 into the stairconfiguration SC as shown. As shown in the stair configuration SC, the track assemblies 154 are arranged in the deployed position 154B. Here, the rear wheels 152 are positioned significantly closer to the front wheels 122 compared to operation in the chair configuration CC, and are also arranged further under the seat section 104. It will be appreciated that transitioning the patient transport apparatus 100 from the chair configuration CC to the stair configuration SC has resulted in minimal patient movement relative to the support structure 102 as the carrier assembly 148 pivots about the hub axis HA and moves the rear wheels 152 closer to the front wheels 122 in response to movement of the track assemblies 154 to the deployed position 154B.

[0083] Furthermore, while the arrangement of the patient’s center of gravity has not changed significantly relative to the support structure 102, the longitudinal distance which extends between the patient’s center of gravity and the location at which the rear wheels 152 contact the floor surface FS has shortened considerably. Because of this, the process of “tilting” the patient transport apparatus 100 (e.g., about the rear wheels 152) to transition toward contact between the track assemblies 154 and the stairs ST, as depicted in Figure 12C, is significantly more comfortable for the patient than would otherwise be the case if the patient transport apparatus 100 were “tilted” about the rear wheels 152 from the chair configuration CC (e.g., with the rear wheels 152 positioned further away from the front wheels 122). Put differently, the arrangement depicted in Figure 12C is such that the patient is much less likely to feel uncomfortable, unstable, or as if they are “falling backwards” during the “tilting” process. Here too, the caregivers are afforded with similar advantages in handling the patient transport apparatus 100, as the arrangement of the rear wheel 152 described above also makes the “tilting” process easier to control and execute. In Figure 12D, the caregivers are shown continuing to support the patient transport apparatus 100 in the stair configuration SC as the belts 156 of the track assemblies 154 are brought into contact with the edge of the top stair ST.

[0084] In Figures 12E and 12F, the caregivers are shown continuing to support the patient transport apparatus 100 in the stair configuration SC as the belts 156 of the track assemblies 154 contact multiple stairs ST during descent

[0085] The patient transport apparatus 100 is configured to operate in a variety of states and modes in certain versions, including for example in or between one or more inactive states SI and / or one or more active states SA. During the inactive state SI, power consumption of the patient transport apparatus 100 is limited as the motor is not controlling movement of the belt during thisstate, and during the active state SA the controller 212 may be utilized to control movement of the belt 156 with the motor 188 of the patient transport apparatus 100.

[0086] It will be appreciated that the controller 212 may be configured to operate in a variety of inactive states SI and active states SA. The controller 212 may be configured to operate in (or between) a sleep mode MS of the inactive state SI and an active mode MS of the inactive state SI. The controller 212 may also operate in a variety of inactive states, for example, a low charge mode MLC of the inactive state SI, and / or a battery disconnect mode MBD of the inactive state SI which are discussed in detail in U.S. Patent Publication No. 2021 / 0196539, the disclosure of which is hereby incorporated by reference in its entirety.

[0087] During the sleep mode MS of the inactive state SI, power consumption of the patient transport apparatus 100 is limited. In some versions, power consumption of the patient transport apparatus 100 may be limited by only allowing the controller 212 to provide power from the battery 206 to certain components of the patient transport apparatus 100. For example, during the sleep mode MS, the controller 212 may be unable to generate and transmit control signals to some of the one or more powered devices, or components thereof, to drive the patient transport apparatus 100. Here, however, the controller 212 may be configured to provide power to the user interface 204. In the sleep mode MS, the user interface 204 may be prevented from emitting light, but may be configured to receive input generate by user engagement of any portion of the user interface 204. Additionally, in some instances of the sleep mode MS, one or more of the controller 212, the motor 188, the geartrain 192, and / or the track assemblies 154 may also be configured to “brake” or otherwise prevent movement of the belts 156.

[0088] During active mode MA of the inactive state, the controller 212 may not limit power consumption of any component of the patient transport apparatus 100. For example, the user interface 204 may emit light for a predetermined period of time in response to user engagement of one of the input controls 214, 216, 218, 222, 224, 322, 324, 326, 328, and 334. Various other components of the patient transport apparatus 100 may be provided power upon demand without limitation during the active mode MA of the inactive state SI.

[0089] The controller 212 may be configured to operate in a drive mode MD during the active state SA to control a direction of movement of the belt 156. In some versions, the controller 212 may be configured to additionally operate in additional modes to the drive mode during the active state SA such as a hold mode MH of the active state SA for limiting movement of the belt 156 tofacilitate a controlled descent of the patient transport apparatus 100 along stairs ST. The hold mode is disclosed by the discussed in detail in U.S. Patent Publication No. 2021 / 0196539, previously incorporated by reference.

[0090] In some versions, the user interface 204 may comprise one or more light modules 210 realized as backlight modules 338 arranged to illuminate various input controls 214, 216, 218, 222, 224, 322, 324, 326, 328, 334 and / or indicators 220, 330, 32 under certain operating conditions. In some versions, the user interface 204 may comprise one or more light modules 210 configured to, among other things, provide status information to the caregiver.

[0091] In the representative version illustrated herein, the controller 212 may be operable in sleep mode in which power consumption is limited, and the active mode SA in which power consumption is not limited such as when the controller 212 controls movement of the belt 156 with the motor 188 of the patient transport apparatus 100. As previously described, the controller 212 may be configured to operate in a variety of other modes / states not explicitly discussed herewith but discussed in greater detail in U.S. Patent Publication No. 2021 / 0196539, previously incorporated by reference.

[0092] As noted above, the direction input controls 216 may include the first direction input control 322 and the second direction input control 324. Here, the first direction input control 322 may be configured to select a drive direction of the motor 188 in order to ascend stairs. The second direction input control 324 may be configured to select a drive direction of the motor 188 in order to descend stairs.

[0093] The one or more speed input controls 218 may be configured to select between the plurality of drive speeds DS1, DS2, DS3 of the motor 188. The speed indicator 332 may be disposed adjacent to the one or more speed input controls 218. The speed indicator 332 may be configured to display the selected one of the plurality of drive speeds DS1, DS2, DS3 of the motor 188 to the user.

[0094] The plurality of drive speeds DS1, DS2, DS3 may correspond to predetermined speed settings (a specific RPM setting) stored in memory of the controller 212. The plurality of drive speeds DS1, DS2, DS3 may include a first drive speed DS1, a second drive speed DS2, and a third drive speed DS3. The first drive speed DS1 corresponds to the lowest of the plurality of drive speeds DS1, DS2, DS3. The third drive speed DS3 corresponds to the highest drive speed of the plurality of drive speeds DS1, DS2, DS3. The second drive speed DS2 corresponds to a speed inbetween the first drive speed DS1 and the third drive speed DS3. It will be appreciated that the forgoing are non-limiting, illustrative examples of three discreet drive speeds, and other configurations are contemplated, including without limitation additional and / or fewer drive speeds, drive speeds defined in other ways, and the like.

[0095] As noted above, the one or more speed input controls 218 may include a first speed input control 326 and a second speed input control 328. The controller 212 may be configured to increase the selected speed to the next higher drive speed setting in response to the user engagement of the first speed input control 326. For example, in response to receiving user input generated by user engagement of the first speed input control 326 when the cunent selected drive speed is the first drive speed DS1, the controller 212 may set the current speed to the second drive speed DS2. The controller 212 may be configured to decrease the selected drive speed to the next lower drive speed setting in response to user engagement of the second speed input control 328. For example, when the current selected drive speed is the second drive speed DS2, the controller 212 may set the current speed to the first drive speed DS1 in response to user engagement of the second speed input control 328.

[0096] In some versions, the controller 212 may be configured to initially select the first drive speed DS1 of the plurality of drive speeds DS1, DS2, DS3 in response to user engagement of the direction input controls 216 following the change in operation from the inactive state SI to the active state SA. However, it is contemplated that the controller 212 may be configured alternatively, such as to initially select the second drive speed DS2 or the third drive speed DS3 of the plurality of drive speeds DS1, DS2, DS3.

[0097] The controller 212 may be configured to selectively permit operation of the motor 188 in response to receiving user input generated by engagement of one of the activation input controls 214 (e.g., the first activation input control 222 or the second activation input control 224). For example, the controller 212 may be configured to permit operation of the motor 188 in response to user engagement of at least one of the activation input controls 214 following user engagement of the direction input control 216 to drive the belt 156 in a selected drive direction. In another example, the controller 212 may be configured to permit operation of the motor 188 in response to user engagement of the activation input controls 214 within a predetermined period following engagement of the direction input control 216. After the predetermined period following user engagement of the direction input control 216 has elapsed, the controller 212 may preventoperation of the motor 188 even when one of the activation input controls 214 is engaged. The controller 212 may also be configured to limit operation of the motor 188 in response to receiving the user input before receiving the user input generated by user selection of one of the direction input controls 216.

[0098] With renewed reference to Figure 1, the loading system 400 is shown adjacent to one of the storage compartments 54 of the transport vehicle 50. A boom 402 is coupled to the transport vehicle 50 and configured to move between a first position within the storage compartment 54 and a second position extending out of the storage compartment 54 (compare Figures 1-2; boom movement not shown in detail). In the illustrated version, the boom 402 supports the patient transport apparatus 100 and the loading system 400 during operation. Extension of the boom 402 may be manual, wherein a caregiver manually moves the boom 402 between the first and second positions. Alternatively, the boom 402 may comprise a powered actuator (not shown) that extends or retracts the boom 402 between the first and second positions. Further, in some versions, the boom 402 may be mechanically linked to a door 58 of the storage compartment 54, such that opening the door 58 automatically moves the boom 402 from the first position to the second position and closing the door 58 of the storage compartment 54 automatically moves the boom 402 from the second position to the first position. The boom 402 may be telescopic, or slidably coupled to the transport vehicle 50. In some versions, the boom 402 or another portion of the loading system 400 may be fixed (e.g., non-movable) relative to the door 58 or another component of the transport vehicle 50. In some versions, the loading system 400 may be configured without a boom 402. As will be discussed in further detail below, the boom 402 may further comprise a brace 450 disposed proximate a distal end of the boom 402 and configured to engage the patient transport apparatus 100 in a nesting manner.

[0099] Referring now to Figures 2-3B, the loading system 400 includes the loading device 404 which is configured to engage the support structure 102 of the patient transport apparatus 100 in the stowed configuration FC for lifting the patient transport apparatus 100 from the lowered position PL (see Figures 3A and 24A) to the raised position PR (see Figures 3B and 24B) for loading into the transport vehicle 50 using the motor 188. To this end, the loading device 404 generally includes a frame 406, a traction roller 432, and an elevating mechanism 405. The frame 406 is configured for engagement with the patient transport apparatus 100 for supporting the patient transport apparatus 100 during loading into and / or unloading from the transport vehicle 50.The traction roller 432 is rotatably supported by the frame 406 and is arranged for operative engagement with the belt 156 of the track assembly 154 of the patient transport apparatus 100. The elevating mechanism 405 is operably coupled between the frame 406 of the loading device 404 and the transport vehicle 50, and includes an actuator interface 407 disposed in rotational communication with the traction roller 432 and configured to move the patient transport apparatus 100 between the lowered position PL (see Figures 3 A and 24A) and the raised position PR (see Figures 3B and 24B) with torque generated by the motor 188 of the patient transport apparatus 100. Versions of the loading device 404 introduced above will be described in greater detail below.

[0100] Referring now to Figure 13, a version of the loading device 404 is shown. In this version, the frame 406 is shown having a body portion 408, a lower portion 410, and an upper portion 412. The lower portion 410 and the upper portion 412 are each coupled to the body portion 408 and are arranged on opposing sides thereof. Said differently, the lower portion 410 is coupled to a lower side of the body portion 408 and the upper portion 412 is coupled to an upper side of the body portion 408 opposite the lower portion 410. The loading device 404 is removably engageable with the patient transport apparatus 100 for lifting the patient transport apparatus 100 into the transport vehicle 50. Specifically, to facilitate removable engagement with the patient transport apparatus 100, the lower portion 410 of the loading device 404 may comprise a hook 414 arranged for engagement with the track assembly 154 of the patient transport apparatus 100. The upper portion 412 may include a latch assembly 416, which may be engageable with the handle assembly 132 of the patient transport apparatus 100 to secure the loading device 404 to the patient transport apparatus 100.

[0101] The frame 406 may be constructed from a lightweight polymer material such as nylon. The polymer material may include a fill material such as glass fiber or carbon fiber to reinforce the frame 406 and increase the stiffness and resist bending. Such examples of the frame 406 may be formed using an injection molding process to form the frame 406 and the trunnion arms 424 (discussed below) with a unitary construction. In another implementation, the frame may be formed from a composite material, such as carbon fiber, fiberglass, aramid, and combinations thereof. Alternatively, the frame 406 may be constructed from a metal such as aluminum, titanium, or magnesium using a casting process, or by CNC machining a raw material.

[0102] The frame 406 may be configured so as to retain a degree of flexibility between the upper portion 412 and the lower portion 410. The upper portion 412 may be spaced from the hook414 such that when the hook 414 is engaged with the cross brace 173 the frame 406 must be elastically deformed in order for the upper portion 412 to be fully engaged with the handle assembly 132. The elastic stress from deformation of the frame 406 exerts a force on the patient transport apparatus 100 that urges the frame 406 toward engagement with the patient transport apparatus 100, thereby preventing unintended removal, and facilitating a close-fitting connection that does not rattle.

[0103] In some versions, the elevating mechanism 405 may include a flexible tension element 418 operably coupled between the actuator interface 407 and the transport vehicle 50. Specifically, a free end 418A of the flexible tension element 418 may be coupled to the boom 402 and a fixed end 418B of the flexible tension element 418 is coupled to the loading device 404. A coupler 420 (see Figure 21) may be attached to both the boom 402 and the free end 418A of the flexible tension element 418 to facilitate installation and removal of the loading device from the transport vehicle 50. The flexible tension element 418 may be implemented in several ways that facilitate operation of the loading system 400. In one exemplary implementation the flexible tension element 418 may be a polymer webbing material, such as nylon or polyester. Additionally, the flexible tension element 418 may be implemented in shapes and materials other than a polymer webbing; materials such as polyethylene, ultra-high-molecular- weight (UHMW) polyethylene, steel, and stainless steel may be braided or twisted to form a flat strap or round rope. In another exemplary implementation, the flexible tension element 418 may be a laminated composite material. As illustrated herein, the laminated composite material may be formed with an elastic pre-stress such that the flexible tension element 418 is biased toward a split tubular shape. Best shown in Figures 18-20, the flexible tension element 418 is in a flat configuration between the fixed end 418B and a guide pin 422 coupled to the upper portion 412 of the loading device 404 and defining a guide aperture 423. Beyond the guide pin 422 the flexible tension element 418 forms a split tubular shape, which due to its shape has some structural rigidity. The portion of the flexible tension element 418 forming the split tubular shape has increased resistance to side-to-side movement, which reduces swaying of the patient transport apparatus 100 when supported by the loading system 400.

[0104] With reference to Figures 20-21, the version of the loading device 404 which employs the flexible tension element 418 as apart of the elevating mechanism 405 is shown. In this version, the actuator interface 407 of the loading device 404 comprises a tension assembly 426. The tensionassembly 426 may be supported by a trunnion arm 424 operatively attached to the frame 405 and, as will be discussed in further detail below, engaged with the flexible tension element 418. In this exemplary version, two trunnion arms 424 are coupled to the frame 406. Here, each of the trunnion arms 424 protrudes in a lateral direction on laterally opposing sides of the body portion 408 and defines a bore 428 extending therethrough. Each of the trunnion arms 424 are spaced from one another to define a gap 430 therebetween. The gap 430 may be arranged in alignment with the guide pin 422 and the upper portion 412 of the frame 406.

[0105] The tension assembly 426 is disposed in rotational communication with the traction roller 432 and may include or otherwise support a driveshaft 434 and a spool member 436. The driveshaft 434 may be rotatably supported in the bore 428 by one or more bearings 438. Here, the driveshaft 434 is disposed in the bore 428 with a traction roller 432 coupled to each opposing end of the driveshaft 434. The traction rollers 432 are coupled so as to transfer rotation to the driveshaft 434 via movement of the belts 156 of the track assemblies 154 via torque generated by the motor 188. The traction rollers 432 are generally cylindrical in shape with a bore extending therethrough. An outer surface of the traction rollers 432 may comprise ridges or other features that facilitate positive engagement between the traction rollers 432 and the belt 156 of the track assembly 154, as will be discussed in further detail below. The ridges may be formed from a rubber material that has been molded on to the outer surface of the traction rollers 432 or may be attached by compression. Other materials and shapes of the ridges are also contemplated.

[0106] The spool member 436 is coupled to the driveshaft 434 so as to transfer rotation from driveshaft 434 to the spool member 436. In this way, rotation of the traction rollers 432 imparts corresponding rotation on the driveshaft 434, which in turn rotates the spool member 436. The spool member 436 may comprise an inner member 440, which is engaged with the driveshaft 434, and an outer member 442, which may be at least partially disposed around the inner member 440. The spool member 436 is arranged on the driveshaft 434 and disposed in the gap 430 defined between the trunnion arms 424. As is best shown in Figure 20, the spool member 436 is arranged in alignment with and parallel to the guide pin 422.

[0107] As mentioned above, the spool member 436 is coupled to the driveshaft 434 for rotation therewith. The spool member 436 is further coupled to the flexible tension element 418. Said differently, the fixed end 418B of the flexible tension element 418 is coupled to the spool member 436 for movement therewith. The flexible tension element 418 is routed from the coupler 420 atthe free end 418A, passes through the guide aperture 423 between the frame 406 and the guide pin 422, and is coupled to the spool member 436 at the fixed end 418B. More specifically, the flexible tension element 418 is wrapped around the inner member 440 of the spool member 436 between the inner member 440 and the outer member 442, which prevents the flexible tension element 418 from unraveling from the tension assembly 426. When the flexible tension element 418 is coupled to the spool member 436, rotation of the traction rollers 432 imparts corresponding rotation on the spool member 436, which coils flexible tension element 418 around the spool member 436, thereby shortening the effective length of the flexible tension element 418 to facilitate moving the patient transport apparatus 100 from the lowered position PL (see Figure 3A) to the raised position PR (see Figure 3B) using torque generated by the motor 188 of the patient transport apparatus 100. Rotation of the traction rollers 432 in a first direction (e.g., clockwise) coils the flexible tension element 418 around the spool member 436 and rotation of the traction rollers 432 in a second direction (e.g., anti-clockwise) uncoils the flexible tension element 418 from the spool member 436.

[0108] In some versions, the loading device 404 may further comprise a latch assembly 416 coupled to the frame 406. The latch assembly 416 is arranged adjacent to the upper portion 412 of the frame 406 and configured for releasable engagement with the handle assembly 132 of the patient transport apparatus 100, as will be discussed in further detail below. The latch assembly 416 may be actuatable by a caregiver to move between an unlatched configuration, in which the handle assembly 132 can be removed from the latch assembly 416, and a latched configuration, in which the handle assembly 132 is retained in the latch assembly 416. In some implementations the latch assembly 416 may be spring biased toward the latched configuration and such that the latch assembly 416 automatically returns to the latched configuration from the unlatched configuration. The latch assembly 416 may be operated by first engaging the handle assembly 132 with latch assembly 416 and urging the handle assembly 132 into the latch assembly 416 such that the handle assembly 132 is retained in engagement with the upper portion of the frame 406.

[0109] Turning now to Figures 13-19, various stages of operation of the illustrated version of the loading system 400 are shown. Specifically, Figures 13-15 show the loading system 400 in a lowered position PL (see also Figure 3 A), while Figure 16 shows the loading system 400 in a raised position PR (see also Figure 3B). In Figure 13, the patient transport apparatus 100 is arranged adjacent to the transport vehicle 50 and disconnected from the loading system 400. Thepatient transport apparatus 100 is shown in the chair configuration CC suitable to transport the patient across ground or floor surfaces. Turning to Figure 14, the patient transport apparatus 100 has been placed in the stowed configuration FC with the track assemblies 154 facing the loading device 404 in preparation for coupling the patient transport apparatus 100 to the loading device 404 (see also Figure 3A which depicts the patient transport apparatus 100 in the stowed configuration FC and coupled to the frame 406 of the loading device 404 at the lowered position PL).

[0110] Turning now to Figure 15, the patient transport apparatus 100 and the loading device 404 are shown in a cross-sectional view with the loading device 404 partially coupled to the patient transport apparatus 100. The upper portion 412 of the frame 406 is tilted away from the handle assembly 132 and the hook 414 is placed around and below the cross brace 173. Here, the tension assembly 426 and the latch assembly 416 are not yet engaged with the patient transport apparatus 100. To fully engage the patient transport apparatus 100 with the loading device 404 the upper portion 412 of the frame 406 is pivoted toward the handle assembly 132 until the handle assembly 132 is seated in the latch assembly 416, thereby retaining the patient transport apparatus 100 to the loading device 404. In the fully coupled position, shown in Figures 16-19 (see also Figure 3A), the tension assembly 426 is engaged with the belts 156 of the track assembly 154 and the patient transport apparatus 100 is able to be lifted by the loading system 400.

[0111] Operation of the loading system 400 is powered by the engagement between the tension assembly 426 and the track assembly 154. Specifically, the traction rollers 432 directly contact the belts 156 of the track assembly 154 for corresponding movement therewith. Operation of the track assembly 154 in a first direction causes movement of the belts 156, which in turn rotates the traction rollers 432 in the first direction. Likewise, operation of the track assembly 154 in a second direction causes movement of the belts 156, which in turn rotates the traction rollers 432 in the second direction. As is described above, operation of the track assembly 154 is powered by the motor 188, which uses electrical energy stored the battery 206 to create torque capable of rotating the drive pulley 174 to move the belts 156. When engaged with the tension assembly 426, this powered operation of the track assembly 154 is used to lift and lower the loading device 404, and in turn the patient transport apparatus 100. Said differently, the motor 188 and track assembly 154 are utilized in cooperation with loading device 404 to effect powered loading of the patienttransport apparatus 100 into the transport vehicle by moving the patient transport apparatus 100 between the lowered position PL and the raised position PR.

[0112] Figures 18 and 19 show two stages of operation of the loading system 400 when loading and lifting the patient transport apparatus 100. Figure 18 shows the loading device 404 in the lowered position PL with the patient transport apparatus 100 on, or near, the ground surface in preparation for loading or removal from the frame 406 of the loading device 404 (see also Figure 3A). Here, the flexible tension element 418 is nearly fully extended from the tension assembly 426 and uncoiled from the spool member 436. Figure 19 shows the loading device 404 in the raised position PR with the patient transport apparatus 100 lifted off of the ground surface for placement in the transport vehicle 50 (see Also Figure 3B). In this version, the flexible tension element 418 is retracted by the tension assembly 426 and uncoiled from the spool member 436 to a shorter length. The amount of the flexible tension element 418 that is coiled around the spool member 436 in Figure 19 is greater than the amount in Figure 18. Said differently, the coil is larger and has a greater diameter in Figure 19.

[0113] Operation of the loading system 400 may be controlled by the caregiver, such as with the user interface 204 arranged on the patient transport apparatus 100. For example, one or more of the activation input controls 214, the direction input controls, and the speed input controls 218 may be actuated by the caregiver to enable a loading mode of the controller 212. The loading mode may utilize the controls described above to operate the patient transport apparatus 100 similarly to operation on stairs. Alternatively, the loading mode may be specially implemented so as to only be accessible when the patient transport apparatus 100 is in the stowed configuration FC. For example, when the patient transport apparatus 100 is in the stair configuration SC, the user interface 204 functions as described above and when the patient transport apparatus 100 is in the stowed configuration the loading mode is enabled and the user interface 204 is changed to simplify operation of the patient transport apparatus 100. Changes to the user interface 204 may include which controls operate a particular function; the activation input controls 214 positioned on the top of the handle assembly 132 may be reconfigured to control the motor 188 and track assemblies 154 to effect lifting and lowering of the loading device 404. It is contemplated that caregiver selection or adjustment of speed as well as activation / deactivation of the motor 188 may be eliminated in the loading mode. Said differently, the controller 212 may be configured to only permit operation of the motor 188 when the appropriate user control 204 is being held (i.e., amomentary switch), and because the patient transport apparatus 100 is unoccupied and has a known weight adjustment of the lifting speed may be unnecessary.

[0114] As mentioned above, the brace 450 may be disposed at the distal end of the boom 402 to receive the handle assembly 132 of the patient transport apparatus 100 when in the raised position PR. The brace 450 may be shaped with an inverse or opposite profile of the handle assembly 132 to receive the handle assembly 132 in a nesting manner so as to cradle the handle assembly 132 and prevent substantial movement of the patient transport apparatus 100 when engaged with the brace 450. To align the handle assembly 132 with the brace 450 when lifting the patient transport apparatus 100, the coupler 420 (Figure 21), which is arranged at the free end 418 A of the flexible tensioning element 418, is coupled to the boom 402 on an inside of the brace 450. Said differently, the flexible tensioning element 418 is arranged inside a cavity of the brace 450 to lift the handle assembly 132 into the brace 450.

[0115] In addition to, or in the alternative of, the brace 450, a shelf 452 may be coupled to the transport vehicle 50 generally below the boom 402. Similar to the brace 450, the shelf 452 may be configured to receive the patient transport apparatus 100 when raised to brace the patient transport apparatus 100 when stowed. The shelf 452 may be shaped with an inverse or opposite profile of a lower portion of the patient transport apparatus 100 to receive the patient transport apparatus 100 in a nesting manner so as to cradle the patient transport apparatus 100 and prevent substantial movement when the transport vehicle 50 is in motion. To engage the patient transport apparatus 100 with the shelf 452, the patient transport apparatus 100 is first lifted to a height such that the lower portion of the patient transport apparatus 100 is above the shelf 452, and subsequently lowered onto the shelf 452. Unlike the brace 450, the shelf 452 supports the weight of the patient transport apparatus 100, which prevents the patient transport apparatus 100 from unintended lowering while stowed. In some implementations the shelf 452 may be selectively deployable having a retracted position and an extended position. In the retracted position (Figure 2) the shelf 452 is flush with the door 58 of the transport vehicle 50 and in the extended position (Figure 1) the shelf 452 protrudes to support the patient transport apparatus 100.

[0116] Turning now to Figure 22, a second implementation of the loading device 404' is shown. As will be appreciated from the subsequent description below, the second implementation of the loading device 404' is similar to the loading device 404 described above in connection with Figures 13-21. As such, the components and structural features of the second implementation ofthe loading device 404' that are the same as, or that otherwise correspond to, the first implementation of the loading device 404 are provided with the same reference numerals with the addition of a prime symbol (e.g., 404 and 404'). While the specific differences between these implementations will be described in detail, for the purposes of clarity, consistency, and brevity, only certain structural features and components common between these versions will be discussed and depicted in the drawings of the second implementation of the loading device 404'. Here, unless otherwise indicated, the above description of the first implementation of the loading device 404 may be incorporated by reference with respect to the second implementation of the loading device 404' without limitation.

[0117] Shown in Figure 22, in the second implementation of the loading device 404' the tension assembly 426' may comprise a resistance mechanism 460' operatively engaged with the driveshaft 434'. The tension assembly 426' may further comprise a pair of bevel gears 462A', 462B', which rotationally couple the resistance mechanism 460' to the driveshaft 434'. A first bevel gear 462A' is arranged on the driveshaft 434' and a second bevel gear 462B' is coupled to the resistance mechanism 460'. Engagement between the respective bevel gears 462A', 462B' facilitates simultaneous rotation of the resistance mechanism 460' and the driveshaft 434'. In various implementations of the resistance mechanism 460', rotation of the driveshaft 434' is inhibited or otherwise restricted to prevent unintended movement of the lifting device 404'. Said differently, the resistance mechanism 460' provides a braking force or resisting force against rotation of the driveshaft 434'.

[0118] In one implementation the resistance mechanism 460' may take the form of a brake, which may be selectively activated by the caregiver once the patient transport apparatus 100 has been lifted by the lifting device 404'. When the brake is engaged rotation of the driveshaft 434' is prevented. This implementation may be desirable to prevent the weight of the patient transport apparatus 100 from back driving the track assemblies 154 and motor 188 when the patient transport apparatus 100 is supported by the loading device 404'. Similarly, the brake would prevent the loading device 404' from lowering due to slipping between the traction rollers 432' and the belts 156. Furthermore, the brake may be implemented as a friction brake, which may permit a variable amount of slip to slow or completely stop the descent of the patient transport apparatus 100, or as a mechanical interlock, which prohibits downward motion when engaged.

[0119] In another implementation the resistance mechanism 460' may take the form of an inertia reel, which is engaged in response to a sudden or rapid acceleration of the driveshaft 434'. The inertia reel is configured to engage when the acceleration of the driveshaft 434' is above a predetermined level, indicative of the flexible tension element 418' rapidly uncoiling from the spool member 436'. Typically, rapid uncoiling of the flexible tension element 418' is associated with the loading device 404' and patient transport apparatus 100 falling. For example, if a component within the track assembly 154 were to fail the patient transport apparatus 100 could fall to the ground, potentially causing further damage to the patient transport apparatus 100. The inertia reel is configured to engage in this scenario to arrest the falling patient transport apparatus 100 before contacting the ground.

[0120] In yet another implementation the resistance mechanism 460' may take the form of a retracting spring, which automatically rewinds the flexible tension element 418' around the spool member 436' when the loading device 404' is decoupled from the patient transport apparatus 100. When the patient transport apparatus 100 is unloaded from the transport vehicle 50 and decoupled from the loading device 404', the loading device 404' is generally near the lowest position with the flexible tension element 418' fully extended and may be at a height that is lower than the bottom of the storage compartment 54. In order to facilitate easy storage of the loading device 404' without the patient transport apparatus 100 the retracting spring may return the loading device 404' to a height above the bottom of the storage compartment 54. Downward movement of the loading device 404' below the bottom of the storage compartment 54 may wind the retracting spring such that when the patient transport apparatus 100 has been decoupled energy stored in the retracting spring automatically lifts the loading device 404' to a height above the bottom of the storage compartment 54.

[0121] It is contemplated that the aforementioned forms of the resistance mechanism 460' described above could be utilized individually or integrated into a single resistance mechanism 460' and utilized in combination with each other. The resistance mechanism 460' may incorporate the functions of the brake, the inertia reel, and the retracting spring into the same device. Alternatively, the resistance mechanism may incorporate a combination of any two of the brake, the inertia reel, and the retracting spring. For example, the resistance mechanism 460' may function as the inertia reel and the brake and not as the retracting spring. Alternatively, the resistance mechanism 460' may function as the brake and the retracting spring and not as the inertiareel. Finally, the resistance mechanism 460' may function as the inertia reel and the retracting spring and not as the brake.

[0122] Turning now to Figure 23, a third implementation of the loading device 404" is shown. As will be appreciated from the subsequent description below, the third implementation of the loading device 404" is similar to the loading device 404 described above in connection with Figures 13-21. As such, the components and structural features of the third implementation of the loading device 404" that are the same as, or that otherwise correspond to, the first implementation of the loading device 404 are provided with the same reference numerals with the addition of a double-prime symbol (e.g., 404 and 404"). While the specific differences between these implementations will be described in detail, for the purposes of clarity, consistency, and brevity, only certain structural features and components common between these versions will be discussed and depicted in the drawings of the third implementation of the loading device 404". Here, unless otherwise indicated, the above description of the first implementation of the loading device 404 may be incorporated by reference with respect to the third implementation of the loading device 404" without limitation.

[0123] In the third implementation of the loading device 404" shown in Figure 23, the frame 406" may further comprise a pivoting connection 470". The pivoting connection 470" is arranged between the body portion 408" and the upper portion 412" of the frame 406" to facilitate pivoting movement therebetween. Said differently, the body portion 408" and the upper portion 412" of the frame 406" may be pivotably coupled by a pivoting connection 470". As previously described above, flexibility between the upper portion 412" and the lower portion 410" or the body portion 408" may increase the engagement between the traction rollers 432" and the belts 156, thereby reducing the possibility of slip between the traction rollers 432" and the belts 156. In order to exert a force that urges the patient transport apparatus 100 into engagement with the loading device 404", the pivoting connection 470" may comprising a torsion spring 472" which is configured to bias the frame 406" to pivot about the pivoting connection 470" that the latch assembly 416" exerts a retaining force on the handle assembly 132. Because the loading device 404" is otherwise constrained by the engagement between the cross brace 173 and the hook 414", the traction rollers 432 are urged toward the belts 156, thereby increasing the friction therebetween.

[0124] Turning now to Figures 24A-26, a fourth implementation of the loading device 404"' is shown. As will be appreciated from the subsequent description below, aspects of the fourthimplementation of the loading device 404'" are similar to the other versions the loading device 404 described herein, such as without limitation the first implementation depicted in Figures 2-3B and 13-21. As such, the components and structural features of the fourth implementation of the loading device 404"' that are the same as, or that otherwise correspond to, the first implementation of the loading device 404 are provided with the same reference numerals with the addition of a tripleprime symbol (e.g., 404 and 404'"). While the specific differences between these implementations will be described in detail, for the purposes of clarity, consistency, and brevity, only certain structural features and components common between these versions will be discussed and depicted in the drawings of the fourth implementation of the loading device 404'". Here, unless otherwise indicated, the above description of the first implementation of the loading device 404 may be incorporated by reference with respect to the fourth implementation of the loading device 404'" without limitation.

[0125] In this version of the loading device 404'", the elevating mechanism 405'" and the actuator interface 407'" are configured differently in comparison to the other versions described above. Here in this version, the elevating mechanism 405'" includes a mount 474"' operatively attached to the transport vehicle 50 (not shown in detail in Figures 24A-24B), and a lift arm 476'" operatively attached to the frame 406'" and pivotably coupled to the mount 474'". The lift arm 476'" is disposed in torque translating relation with the actuator interface 407'" for lifting the patient transport apparatus 100'" from the lowered position PL (see Figure 24A) to the raised position PR (see Figure 24B) with torque generated by the motor 188'" of the patient transport apparatus 100'". While not depicted in detail throughout the drawings, it will be appreciated that the mount 474"' could be configured for attachment to the transport vehicle 50 in a number of different ways, such as to an interior floor within the cargo volume 56 (not shown, but generally known in the art). Other configurations are contemplated.

[0126] In this version, the elevating mechanism 405'" employs a ring gear 478'" operatively attached to the mount 474"', and a geartrain 480'" disposed in torque translating relation between the ring gear 478"' and the actuator interface 407'" to pivot the lift arm 476"' relative to the mount 474'" in response to torque generated by the motor 188'" of the patient transport apparatus 100'" to move the patient transport apparatus 100'" relative to the transport vehicle 50 between the lowered position PL and the raised position PR. In the illustrated version, and as is best depicted in Figure 26, the geartrain 480'" includes a pinion gear 482'" disposed in engagement with the ringgear 478'" and coupled to a pinion shaft 484'" rotatably supported by the lift arm 476"', as well as a lower gearset 486” disposed in rotational communication with the pinion gear 482"', an upper gearset 488"' disposed in rotational communication with the actuator interface 407'", and an arm shaft 490'" rotatably coupled to the lower gearset 486'" and to the upper gearset 488"' to translate torque between the actuator interface 407'" and the pinion gear 482'". In the illustrated version, the lift arm 476'" has a hollow profile with the arm shaft 490'" and other components of the geartrain 480"' disposed at least partially within the hollow profile of the arm shaft 490'".

[0127] As is best depicted in Figure 25, the geartrain 480'" also includes a first intermediate gearset 492'" operatively attached to the upper portion 412'" of the frame 406'" and disposed in rotational communication with the upper gearset 488'", a second intermediate gearset 494'" operatively attached to the lower portion 410'" of the frame 406'" and disposed in rotational communication with the actuator interface 407'", and an intermediate shaft 496'" rotatably coupled to the first intermediate gearset 492'" and to the second intermediate gearset 494'" to translate torque between the actuator interface 407'" and the pinion gear 482'".

[0128] In this version, as the traction rollers 432'" are rotated via movement of the belts 156 of the track assemblies 154'" effected by the motor 188'", the torque is transferred through the geartrain 480'" until it reaches the pinion gear 482'". Here, because the pinion gear 482"' is supported by the lift arm 476'" and because the ring gear 478'" is coupled to the mount 474'", the transferred torque causes the pinion gear 482'" meshed with the ring gear 478'" to move relative to the ring gear 478'" and, thus, pivot the lift arm 476'" relative to the mount 474'" to effect movement of the patient transport apparatus 100 between the lowered position PL (see Figure 24A) and the raised position PR (see Figure 24B). While the geartrain 480'" illustrated in the drawings includes various arrangements of meshed gears (e.g., miter gears), it will be appreciated that various configurations are contemplated, and various styles, sizes, and / or types of gears could be employed (e.g., worm gears to inhibit manual movement, different gear ratios, different arrangements of shafts, bearings, bushings, and the like; not shown). Moreover, it will be appreciated that torque from the motor 188 could be employed to facilitate operation of various types, styles, and / or configurations of elevating mechanisms 405'".

[0129] Several instances have been discussed in the foregoing description. However, the aspects discussed herein are not intended to be exhaustive or limit the disclosure to any particular form. Various modifications to these aspects will be readily apparent to those skilled in the art,and the generic principles defined herein may be applied to other aspects without departing from the scope of the disclosure. The terminology that has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations are possible in light of the above teachings and the disclosure may be practiced otherwise than as specifically described.

[0130] The present disclosure also comprises the following clauses, with specific features laid out in dependent clauses, that may specifically be implemented as described in greater detail with reference to the configurations and drawings above.CLAUSESI. A loading system for use with a transport vehicle, the loading system comprising: a patient transport apparatus comprising: a support structure, a seat section and a back section operatively attached to the support structure for supporting a patient during transport, a track assembly operatively attached to the support structure and including a movable belt for engaging stairs, wherein the track assembly is arranged for selective operation between a retracted position and a deployed position where the track assembly is arranged to engage stairs, and wherein the patient transport apparatus is operable between: a chair configuration where the track assembly is in the retracted position for supporting the patient transport apparatus for movement along floor surfaces, a stair configuration where the track assembly is in the deployed position for supporting the patient transport apparatus for movement along stairs, and a stowed configuration, a motor coupled to the support structure and operably coupled to the track assembly for operating the movable belt, and a battery coupled to the support structure and in electrical communication with the motor; and a loading device configured to engage the support structure in the stowed configuration for lifting the patient transport apparatus from a lowered position to a raised position for loading into the transport vehicle, the loading device comprising:a frame engageable with the patient transport apparatus for supporting the patient transport apparatus during loading into the transport vehicle, a traction roller rotatably supported by the frame and arranged for operative engagement with the movable belt of the track assembly of the patient transport apparatus, and an elevating mechanism operably coupled between the frame of the loading device and the transport vehicle, the elevating mechanism including an actuator interface disposed in rotational communication with the traction roller and being configured to move the patient transport apparatus between the lowered position and the raised position with torque generated by the motor of the patient transport apparatus.II. The loading system of clause I, wherein the actuator interface of the elevating mechanism comprises a tension assembly disposed in rotational communication with the traction roller, and wherein the elevating mechanism includes a flexible tension element operably coupled between the tension assembly and the transport vehicle, wherein rotation of the traction roller moves the flexible tension element relative to the frame of the loading device to shorten an effective length of the flexible tension element for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.III. The loading system of clause II, wherein the frame includes an upper portion defining a guide aperture, and wherein the flexible tension element is slidably received in the guide aperture.IV. The loading system of clause III, wherein the patient transport apparatus further comprises a handle, and wherein the upper portion of the frame comprises a latch assembly for releasably engaging the handle to secure the patient transport apparatus the frame.V. The loading system of any of clauses II-IV, wherein the tension assembly further comprises a spool member coupled to the traction roller, and wherein the flexible tension element is wrapped around the spool member, and wherein rotation of the traction roller in a first direction coils the flexible tension element around the spool member to move the patient transport apparatus towards the raised position, and rotation of the traction roller in a second direction uncoils the flexible tension element from the spool member to move the patient transport apparatus towards the lowered position.VI. The loading system of any of clauses II-V, further comprising a resistance mechanism operably engaged with the tension assembly, wherein the resistance mechanism is operable to resist rotation of the tension assembly.VII. The loading system of clause VI, wherein the resistance mechanism comprises a brake selectively engageable by a caregiver to prevent rotation of the tension assembly.VIII. The loading system of clause VI, wherein the resistance mechanism comprises an inertia reel operably engaged with the tension assembly to stop rotation of the tension assembly in response to sudden acceleration of the tension assembly.IX. The loading system of clause VI, wherein the resistance mechanism comprises a retracting spring operably engaged with the tension assembly, wherein rotation of the tension assembly in a first direction winds the retracting spring, and wherein the retracting spring rotates the tension assembly in a second direction for raising the loading device in response to disengagement of the patient transport apparatus from the loading device.X. The loading system of any of clauses II- IX, further comprising a lifting boom coupled to the transport vehicle, wherein the flexible tension element is coupled to the lifting boom.XI. The loading system of clause X, wherein the transport vehicle further comprises a storage compartment having a door, and wherein the lifting boom is coupled to the door.XII. The loading system of clause X, wherein the transport vehicle further comprises a storage compartment defining a cargo volume, and wherein the lifting boom is slidably coupled to the transport vehicle and configured for movement between a first position within the cargo volume and a second position extending from the cargo volume.XIII. The loading system of any of clauses I-XII, wherein the elevating mechanism includes a mount operatively attached to the transport vehicle, and a lift arm operatively attached to the frame of the loading device and pivotably coupled to the mount, the lift ami being disposed in torque translating relation with the actuator interface for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.XIV. The loading system of clause XIII, wherein the elevating mechanism further includes a ring gear operatively attached to the mount, and a geartrain disposed in torque translating relation between the ring gear and the actuator interface to pivot the lift arm relative to the mount in response to torque generated by the motor of the patient transport apparatus to move the patienttransport apparatus relative to the transport vehicle between the lowered position and the raised position.XV. The loading system of clause XIV, wherein the geartrain of the elevating mechanism includes a pinion gear disposed in engagement with the ring gear and coupled to a pinion shaft rotatably supported by the lift arm.XVI. The loading system of clause XV, wherein the geartrain of the elevating mechanism further includes a lower gearset disposed in rotational communication with the pinion gear, an upper gearset disposed in rotational communication with the actuator interface, and an arm shaft rotatably coupled to the lower gearset and to the upper gearset to translate torque between the actuator interface and the pinion gear.XVII. The loading system of clause XVI, wherein the lift arm has a hollow profile with the arm shaft disposed at least partially therein.XVIII. The loading system of any of clauses XVI-XVII, wherein the geartrain of the elevating mechanism further includes a first intermediate gearset operatively attached to an upper portion of the frame and disposed in rotational communication with the upper gearset, a second intermediate gearset operatively attached to a lower portion of the frame and disposed in rotational communication with the actuator interface, and an intermediate shaft rotatably coupled to the first intermediate gearset and to the second intermediate gearset to translate torque between the actuator interface and the pinion gear.XIX. The loading system of any of clauses I-XVIII, wherein the loading device further includes a trunnion arm operatively attached to the frame and supporting the traction roller for operative engagement with the movable belt of the track assembly of the patient transport apparatus.XX. The loading system of clause XIX, wherein the trunnion arm is further defined as a first trunnion arm and a second trunnion arm, and wherein the traction roller is further defined as a first traction roller and a second traction roller.XXI. The loading system of any of clauses I-XX, wherein the patient transport apparatus further comprises a controller in electrical communication with the motor, and wherein the controller is configured to operate the motor to drive the movable belt of the track assembly when the patient transport apparatus is engaged with the loading device and in the stowed configuration.XXII. The loading system of clause XXI, wherein engagement between the movable belt of the track assembly and the traction roller is configured to rotate the traction roller when the track assembly is operated by the motor in the stowed configuration to move the patient transport apparatus between the lowered position and the raised position.XXIII. The loading system of clause XXII, wherein the track assembly is further defined as a first track assembly and a second track assembly, and further comprising a cross brace extending laterally between the first track assembly and the second track assembly, and wherein the frame of the loading device includes a lower portion with a hook arranged for engagement with the cross brace for supporting the patient transport apparatus when lifting.XXIV. The loading system of any of clauses I-XXIII, wherein the frame of the loading device includes a body portion, an upper portion, and a lower portion, and wherein the frame is flexible between the upper portion and the lower portion such that when the patient transport apparatus is engaged with the upper portion the traction roller is biased into engagement with the movable belt of the track assembly of the patient transport apparatus to increase friction therebetween.XXV. The loading system of clause XXIV, wherein the upper portion of the frame is pivotably coupled to the body portion of the frame and wherein the loading device further comprises a torsion spring biasing the upper portion relative to the body portion.XXVI. A loading system for use with a transport vehicle, the loading system comprising: a patient transport apparatus comprising: a support structure having a seat section and being movable between a chair configuration and a stowed configuration, a motor coupled to the support structure, a battery coupled to the support structure and in electrical communication with the motor, and a drive element coupled to the support structure and operably coupled to the motor for powered operation, wherein the drive element is moveable between a retracted position and a deployed position; and a loading device configured to engage the support structure in the stowed configuration for lifting the patient transport apparatus from a lowered position to a raised position for loading into the transport vehicle, the loading device comprising:a frame engageable with the patient transport apparatus for supporting the patient transport apparatus during loading into the transport vehicle, a traction roller rotatably supported by the frame and arranged for operative engagement with the drive element of the patient transport apparatus, and an elevating mechanism operably coupled between the frame of the loading device and the transport vehicle, the elevating mechanism including an actuator interface disposed in rotational communication with the traction roller and being configured to move the patient transport apparatus between the lowered position and the raised position with torque generated by the motor of the patient transport apparatus.XXVII. The loading system of clause XXVI, wherein the actuator interface of the elevating mechanism comprises a tension assembly disposed in rotational communication with the traction roller, and wherein the elevating mechanism includes a flexible tension element operably coupled between the tension assembly and the transport vehicle, wherein rotation of the traction roller moves the flexible tension element relative to the frame of the loading device to shorten an effective length of the flexible tension element for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.XXVIII. The loading system of clause XXVII, wherein the frame includes an upper portion defining a guide aperture, and wherein the flexible tension element is slidably received in the guide aperture.XXIX, The loading system of clause XXVIII, wherein the patient transport apparatus further comprises a handle, and wherein the upper portion of the frame comprises a latch assembly for releasably engaging the handle to secure the patient transport apparatus the frame.XXX. The loading system of any of clauses XXVII-XXIX, wherein the tension assembly further comprises a spool member coupled to the traction roller, and wherein the flexible tension element is wrapped around the spool member, and wherein rotation of the traction roller in a first direction coils the flexible tension element around the spool member to move the patient transport apparatus towards the raised position, and rotation of the traction roller in a second direction uncoils the flexible tension element from the spool member to move the patient transport apparatus towards the lowered position.XXXI. The loading system of any of clauses XXVII-XXX, further comprising a resistance mechanism operably engaged with the tension assembly, wherein the resistance mechanism is operable to resist rotation of the tension assembly.XXXII. The loading system of clause XXXI, wherein the resistance mechanism comprises a brake selectively engageable by a caregiver to prevent rotation of the tension assembly.XXXIII. The loading system of clause XXXI, wherein the resistance mechanism comprises an inertia reel operably engaged with the tension assembly to stop rotation of the tension assembly in response to sudden acceleration of the tension assembly.XXXIV. The loading system of clause XXXI, wherein the resistance mechanism comprises a retracting spring operably engaged with the tension assembly, wherein rotation of the tension assembly in a first direction winds the retracting spring, and wherein the retracting spring rotates the tension assembly in a second direction for raising the loading device in response to disengagement of the patient transport apparatus from the loading device.XXXV. The loading system of any of clauses XXVII-XXXIV, further comprising a lifting boom coupled to the transport vehicle, wherein the flexible tension element is coupled to the lifting boom.XXXVI. The loading system of clause XXXV, wherein the transport vehicle further comprises a storage compartment having a door, and wherein the lifting boom is coupled to the door.XXXVII. The loading system of clause XXXV, wherein the transport vehicle further comprises a storage compartment defining a cargo volume, and wherein the lifting boom is slidably coupled to the transport vehicle and configured for movement between a first position within the cargo volume and a second position extending from the cargo volume.XXXVIII. The loading system of any of clauses XXVI-XXXVII, wherein the elevating mechanism includes a mount operatively attached to the transport vehicle, and a lift arm operatively attached to the frame of the loading device and pivotably coupled to the mount, the lift arm being disposed in torque translating relation with the actuator interface for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.XXXIX. The loading system of clause XXXVIII, wherein the elevating mechanism further includes a ring gear operatively attached to the mount, and a geartrain disposed in torque translating relation between the ring gear and the actuator interface to pivot the lift arm relative to the mount in response to torque generated by the motor of the patient transport apparatus to move the patient transport apparatus relative to the transport vehicle between the lowered position and the raised position.XL. The loading system of clause XXXIX, wherein the geartrain of the elevating mechanism includes a pinion gear disposed in engagement with the ring gear and coupled to a pinion shaft rotatably supported by the lift arm.XLI. The loading system of clause XL, wherein the geartrain of the elevating mechanism further includes a lower gearset disposed in rotational communication with the pinion gear, an upper gearset disposed in rotational communication with the actuator interface, and an arm shaft rotatably coupled to the lower gearset and to the upper gearset to translate torque between the actuator interface and the pinion gear.XLII. The loading system of clause XLI, wherein the lift arm has a hollow profile with the arm shaft disposed at least partially therein.XLIII. The loading system of any of clauses XLI-XLII, wherein the geartrain of the elevating mechanism further includes a first intermediate gearset operatively attached to an upper portion of the frame and disposed in rotational communication with the upper gearset, a second intermediate gearset operatively attached to a lower portion of the frame and disposed in rotational communication with the actuator interface, and an intermediate shaft rotatably coupled to the first intermediate gearset and to the second intermediate gearset to translate torque between the actuator interface and the pinion gear.XLIV. The loading system of any of clauses XXVI-XLIII, wherein the loading device further includes a trunnion arm operatively attached to the frame and supporting the traction roller for operative engagement with the drive element of the patient transport apparatus.XLV. The loading system of clause XLIV, wherein the trunnion arm is further defined as a first trunnion arm and a second trunnion arm, and wherein the traction roller is further defined as a first traction roller and a second traction roller.XLVI. The loading system of any of clauses XXVLXLV, wherein the patient transport apparatus further comprises a controller in electrical communication with the motor, and whereinthe controller is configured to operate the motor to power the drive element when the patient transport apparatus is engaged with the loading device and in the stowed configuration.XLVII. The loading system of clause XL VI, wherein the drive element comprises a track assembly including a movable belt for engaging stairs in the deployed position, and wherein engagement between the movable belt of the track assembly and the traction roller is configured to rotate the traction roller when the track assembly is operated by the motor in the stowed configuration to move the patient transport apparatus between the lowered position and the raised position.XLVIII. The loading system of clause XLVII, wherein the track assembly is further defined as a first track assembly and a second track assembly, and further comprising a cross brace extending laterally between the first track assembly and the second track assembly, and wherein the frame of the loading device includes a lower portion with a hook arranged for engagement with the cross brace for supporting the patient transport apparatus when lifting.XLIX. The loading system of any of clauses XXVI-XLVIII, wherein the frame of the loading device includes a body portion, an upper portion, and a lower portion, and wherein the frame is flexible between the upper portion and the lower portion such that when the patient transport apparatus is engaged with the upper portion the traction roller is biased into engagement with the drive element of the patient transport apparatus to increase friction therebetween.L. The loading system of clause XLIX, wherein the upper portion of the frame is pivotably coupled to the body portion of the frame and wherein the loading device further comprises a torsion spring biasing the upper portion relative to the body portion.

Claims

CLAIMSWhat is claimed is:

1. A loading system for use with a transport vehicle, the loading system comprising: a patient transport apparatus comprising: a support structure, a seat section and a back section operatively attached to the support structure for supporting a patient during transport, a track assembly operatively attached to the support structure and including a movable belt for engaging stairs, wherein the track assembly is arranged for selective operation between a retracted position and a deployed position where the track assembly is arranged to engage stairs, and wherein the patient transport apparatus is operable between: a chair configuration where the track assembly is in the retracted position for supporting the patient transport apparatus for movement along floor surfaces, a stair configuration where the track assembly is in the deployed position for supporting the patient transport apparatus for movement along stairs, and a stowed configuration, a motor coupled to the support structure and operably coupled to the track assembly for operating the movable belt, and a battery coupled to the support structure and in electrical communication with the motor; and a loading device configured to engage the support structure in the stowed configuration for lifting the patient transport apparatus from a lowered position to a raised position for loading into the transport vehicle, the loading device comprising: a frame engageable with the patient transport apparatus for supporting the patient transport apparatus during loading into the transport vehicle, a traction roller rotatably supported by the frame and arranged for operative engagement with the movable belt of the track assembly of the patient transport apparatus, and an elevating mechanism operably coupled between the frame of the loading device and the transport vehicle, the elevating mechanism including an actuator interfacedisposed in rotational communication with the traction roller and being configured to move the patient transport apparatus between the lowered position and the raised position with torque generated by the motor of the patient transport apparatus.

2. The loading system of claim 1, wherein the actuator interface of the elevating mechanism comprises a tension assembly disposed in rotational communication with the traction roller, and wherein the elevating mechanism includes a flexible tension element operably coupled between the tension assembly and the transport vehicle, wherein rotation of the traction roller moves the flexible tension element relative to the frame of the loading device to shorten an effective length of the flexible tension element for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.

3. The loading system of claim 2, wherein the frame includes an upper portion defining a guide aperture, and wherein the flexible tension element is slidably received in the guide aperture.

4. The loading system of claim 3, wherein the patient transport apparatus further comprises a handle, and wherein the upper portion of the frame comprises a latch assembly for releasably engaging the handle to secure the patient transport apparatus the frame.

5. The loading system of claim 2, wherein the tension assembly further comprises a spool member coupled to the traction roller, and wherein the flexible tension element is wrapped around the spool member, and wherein rotation of the traction roller in a first direction coils the flexible tension element around the spool member to move the patient transport apparatus towards the raised position, and rotation of the traction roller in a second direction uncoils the flexible tension element from the spool member to move the patient transport apparatus towards the lowered position.

6. The loading system of claim 2, further comprising a resistance mechanism operably engaged with the tension assembly, wherein the resistance mechanism is operable to resist rotation of the tension assembly.

7. The loading system of claim 6, wherein the resistance mechanism comprises a brake selectively engageable by a caregiver to prevent rotation of the tension assembly.

8. The loading system of claim 6, wherein the resistance mechanism comprises an inertia reel operably engaged with the tension assembly to stop rotation of the tension assembly in response to sudden acceleration of the tension assembly.

9. The loading system of claim 6, wherein the resistance mechanism comprises a retracting spring operably engaged with the tension assembly, wherein rotation of the tension assembly in a first direction winds the retracting spring, and wherein the retracting spring rotates the tension assembly in a second direction for raising the loading device in response to disengagement of the patient transport apparatus from the loading device.

10. The loading system of claim 2, further comprising a lifting boom coupled to the transport vehicle, wherein the flexible tension element is coupled to the lifting boom.

11. The loading system of claim 10, wherein the transport vehicle further comprises a storage compartment having a door, and wherein the lifting boom is coupled to the door.

12. The loading system of claim 10, wherein the transport vehicle further comprises a storage compartment defining a cargo volume, and wherein the lifting boom is slidably coupled to the transport vehicle and configured for movement between a first position within the cargo volume and a second position extending from the cargo volume.

13. The loading system of claim 1, wherein the elevating mechanism includes a mount operatively attached to the transport vehicle, and a lift arm operatively attached to the frame of the loading device and pivotably coupled to the mount, the lift arm being disposed in torque translating relation with the actuator interface for lifting the patient transport apparatus from the lowered position to the raised position with torque generated by the motor of the patient transport apparatus.

14. The loading system of claim 13, wherein the elevating mechanism further includes a ring gear operatively attached to the mount, and a geartrain disposed in torque translating relation between the ring gear and the actuator interface to pivot the lift arm relative to the mount in response to torque generated by the motor of the patient transport apparatus to move the patient transport apparatus relative to the transport vehicle between the lowered position and the raised position.

15. The loading system of claim 14, wherein the geartrain of the elevating mechanism includes a pinion gear disposed in engagement with the ring gear and coupled to a pinion shaft rotatably supported by the lift arm.

16. The loading system of claim 15, wherein the geartrain of the elevating mechanism further includes a lower gearset disposed in rotational communication with the pinion gear, an upper gearset disposed in rotational communication with the actuator interface, and an arm shaft rotatably coupled to the lower gearset and to the upper gearset to translate torque between the actuator interface and the pinion gear.

17. The loading system of claim 16, wherein the lift arm has a hollow profile with the arm shaft disposed at least partially therein.

18. The loading system of claim 16, wherein the geartrain of the elevating mechanism further includes a first intermediate gearset operatively attached to an upper portion of the frame and disposed in rotational communication with the upper gearset, a second intermediate gearset operatively attached to a lower portion of the frame and disposed in rotational communication with the actuator interface, and an intermediate shaft rotatably coupled to the first intermediate gearset and to the second intermediate gearset to translate torque between the actuator interface and the pinion gear.

19. The loading system of claim 1, wherein the loading device further includes a trunnion arm operatively attached to the frame and supporting the traction roller for operative engagement with the movable belt of the track assembly of the patient transport apparatus.

20. The loading system of claim 19, wherein the trunnion arm is further defined as a first trunnion arm and a second trunnion arm, and wherein the traction roller is further defined as a first traction roller and a second traction roller.

21. The loading system of claim 1, wherein the patient transport apparatus further comprises a controller in electrical communication with the motor, and wherein the controller is configured to operate the motor to drive the movable belt of the track assembly when the patient transport apparatus is engaged with the loading device and in the stowed configuration.

22. The loading system of claim 21, wherein engagement between the movable belt of the track assembly and the traction roller is configured to rotate the traction roller when the track assembly is operated by the motor in the stowed configuration to move the patient transport apparatus between the lowered position and the raised position.

23. The loading system of claim 22, wherein the track assembly is further defined as a first track assembly and a second track assembly, and further comprising a cross brace extending laterally between the first track assembly and the second track assembly, and wherein the frame of the loading device includes a lower portion with a hook arranged for engagement with the cross brace for supporting the patient transport apparatus when lifting.

24. The loading system of claim 1, wherein the frame of the loading device includes a body portion, an upper portion, and a lower portion, and wherein the frame is flexible between the upper portion and the lower portion such that when the patient transport apparatus is engaged with the upper portion the traction roller is biased into engagement with the movable belt of the track assembly of the patient transport apparatus to increase friction therebetween.

25. The loading system of claim 24, wherein the upper portion of the frame is pivotably coupled to the body portion of the frame and wherein the loading device further comprises a torsion spring biasing the upper portion relative to the body portion.

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