Transfer system for transferring a patient into and / or out of a rescue or ambulance cart

Abstract

The transfer system for transferring a patient to an ambulance or patient transport vehicle is equipped with a patient transport device (10), in particular in the form of a wheelchair. The patient transport device (10) has a propulsion drive (30) which includes motor-driven drive elements (38) such as wheels, rollers, or tracks. The drive elements (38) have an outer surface (52) with external teeth (55) in the form of transverse ribs (57) that rolls on a surface for contact with it. The transfer system is further equipped with a loading and unloading device (53) for driving onto the patient transport device (10), the loading and unloading device (53) having a loading ramp (60).On and / or at the loading ramp (60) tooth profiles (64) with transverse ribs (66) extending transversely to their respective longitudinal extent are formed for meshing with the external teeth (55) of the outer surfaces (52) of the drive elements (38) of the patient transport device (10).

Description

[0001] The invention relates to a transfer system for transferring a patient into and / or out of an ambulance or patient transport vehicle with a loading and unloading device for the ambulance (RTW) or the patient transport vehicle (KTW) for driving by means of a patient transport device, in particular in the form of a wheelchair, with a propulsion drive which has motor-driven drive elements such as wheels or rollers or caterpillar drives, wherein the drive elements have an external toothing provided for contact with a surface, in particular in the form of an outer side provided with transverse ribs.Furthermore, the invention relates to the use of a toothed profile with transverse ribs running transversely to its longitudinal extent for the loading ramp of a loading and unloading device of an ambulance or patient transport vehicle for driving on by means of a patient transport device, in particular in the form of a wheelchair, which has motor-driven drive elements such as wheels or rollers or caterpillar drives, which have an external toothing provided for contact with a substrate, in particular in the form of an outer side provided with transverse ribs.

[0002] To enable ergonomic loading and unloading of patients, it is advantageous if the corresponding patient transport device has a drive system (ground drive). Such patient transport devices, usually in the form of gurneys or wheelchairs, are generally known (see, for example, DE 33 46 836 A1, DE 20 2022 100 835 U1, and US Pat. No. 8 783 392 B2).

[0003] Driving onto a loading ramp can be problematic with such patient transport devices, especially if the loading ramp is wet and therefore slippery, for example, due to precipitation. This also applies to the drive elements of the patient transport device's propulsion system. Loading ramps with "rough" surface structures are described, for example, in JP 2014-201186 A and US 2011 / 0023245 A1.

[0004] The object of the invention is to remedy this situation and to create a transfer system for transferring a patient into and / or out of an ambulance or patient transport vehicle with improved accessibility of the loading ramp of the loading and unloading device.

[0005] To achieve this object, the invention proposes a transfer system for transferring a patient into and / or out of an ambulance or patient transport vehicle, with a patient transport device, in particular in the form of a hospital chair, the patient transport device being provided with a propulsion drive which has motor-driven drive elements such as wheels or rollers or caterpillar drives, the drive elements having an outer side which rolls on a surface for contact therewith and has external teeth in the form of transverse ribs, and a loading and unloading device for driving over by means of the patient transport device, the loading and unloading device being provided with a loading ramp and one or more tooth profiles arranged or formed on and / or on the loading ramp, with transverse ribs running transversely to their respective longitudinal extent for meshing with the external teeth of the outer sides of the drive elements of the patient transport device.

[0006] Furthermore, to achieve this object, the use of a toothed profile with transverse ribs running transversely to its longitudinal extent is proposed for the loading ramp of a loading and unloading device of an ambulance or patient transport vehicle for driving on by means of a patient transport device, in particular in the form of a wheelchair, which has motor-driven drive elements such as wheels or rollers or caterpillar drives, which have an external toothing provided for contact with a substrate, in particular in the form of an outer side provided with transverse ribs, by meshing the external toothing of the outer sides of the drive elements of the patient transport device with the toothed profile on and / or on the loading ramp.

[0007] According to the invention, it was recognized that a positive connection with the propulsion drive of an automatically advanceable patient transport device can be ensured in a simple manner on the inclined loading ramp of the loading and unloading device of an ambulance or KTW, in that the drive elements of the patient transport device have an external toothing, in particular in the form of an outer side provided with transverse ribs, in order to also provide toothing profiles on the loading ramp which have transverse ribs running transversely to their respective longitudinal extents for meshing with the outer sides of the drive elements of the patient transport device.

[0008] The toothed profiles on the loading ramp can also be designed as toothed belts with transverse ribs on one side or as "racks" with teeth on one side forming the transverse ribs. Alternatively, such a surface structure can be incorporated into the loading ramp. The loading ramp itself can be designed as a plate with, so to speak, two "tracks" of toothed profiles, or the loading ramp can consist of two webs that are parallel in use, each provided with a toothed profile. The toothing, i.e., the density of the transverse ribs per unit length of the toothed profiles of the loading ramp, is expediently equal to the transverse rib density on the outer sides of the drive elements of the propulsion drive of the patient transport device.The "external toothing" of the wheelchair's drive elements is also advantageous in that it creates a positive connection with the edges of a staircase when the wheelchair is used to travel up or down it.

[0009] The patient transport device used according to the invention is preferably a hospital chair as described in DE 10 2023 103 710, the content of which is hereby incorporated by reference into the subject matter of the present patent application.

[0010] In a further advantageous embodiment of the invention, that the loading ramp has a first end for resting on a surface and a second end facing away from the first end, that each toothed profile has a material layer on the underside from which the transverse ribs project upwards, that each transverse rib of a toothed profile has a first side wall facing the first end of the loading ramp and an upstanding second side wall facing the second end of the loading ramp and an upper side connecting both side walls, and that each transverse rib is chamfered in the transition region of the second side surface to the upper side.

[0011] By chamfering the transverse ribs of the toothed profiles on those side walls of the transverse ribs facing the second end of the loading ramp, the transverse ribs on the outer sides of the drive elements reliably engage with the transverse ribs of the toothed profiles. The transverse ribs on the outer sides of the drive elements "roll," so to speak, into the spaces between the transverse ribs of the toothed profiles of the loading ramp as the drive elements rotate. This process is facilitated by the described chamfer in the transition area between the second side surfaces facing the second end of the loading ramp and the upper side of the transverse ribs of the toothed profiles. The chamfer of the second side wall of each transverse rib preferably forms an angle of 20° to 40°, 25° to 45°, or 30° to 35° with an imaginary plane running perpendicular to the carrier layer of the toothed profiles.

[0012] When driving up and down the loading ramp, the drive element, which lies tangentially on the gear profiles, engages with the transverse ribs of its external teeth into the transverse ribs of the gear profiles of the loading ramp. The transverse rib of the external teeth of the drive gear is pressed against the upward-facing wall of the transverse rib of the gear profile. The preferably flexible transverse rib on the external teeth of the drive element thus adapts to the contour of the transverse rib of the gear profile. It is advantageous here if the two interacting surfaces—the angle of incidence of the transverse rib of the external teeth of the drive gear and the wall of the transverse rib of the gear profile—have the same angle. This reduces the shortening of the path from rib to rib, and the chamfer allows for plunging into the next "gap" to the adjacent transverse rib.

[0013] The second side walls of the transverse ribs of each tooth profile protrude vertically from the material layer to the chamfer.

[0014] The design of the first side walls of the transverse ribs is less critical, since the secure engagement of the transverse ribs of the external toothing of the drive elements with the transverse ribs of the toothing profiles of the loading ramp on the second side walls must follow, both when driving up the loading ramp and when driving down.

[0015] In an advantageous embodiment of the invention, it can therefore be provided that the first side walls of each transverse rib of each tooth profile are free of a chamfer in the transition region to the upper side of the transverse rib and / or run perpendicular to the material layer or at an acute or obtuse angle to the material layer.

[0016] An even more reliable engagement of the transverse ribs on the external toothing of the drive elements with the transverse ribs of the toothing profiles is advantageously achieved by that adjacent transverse ribs of each toothing profile each have a first distance from one another, that adjacent transverse ribs of the external toothing of each drive element each have a second distance from one another and that the first distance is in particular 5% to 15% or in particular 7% to 17% or in particular 9% to 13% greater than the second distance.

[0017] The cross ribs on the external toothing of the drive elements move in a circular line when the drive elements are driven, whereby a cross rib of the external toothing of a drive element must pass the lower or upper of the two adjacent cross ribs before entering the space between two cross ribs of the toothing profiles (depending on the direction in which the loading ramp is used, namely for driving the patient transport device into the ambulance or emergency vehicle or for driving out of the ambulance or emergency vehicle). Due to the arrangement of the cross ribs of the external toothing of the drive elements on a circular line, the center-to-center distance between two adjacent cross ribs, i.e. the distance between the side walls of the two cross ribs pointing in the same direction, is slightly greater than with an (imaginary) straight line of the external toothing.The next the distance of those side walls of the transverse ribs of the external toothing of the drive elements, which when meshing with the toothing profiles rest on the second side walls of the transverse ribs of the toothing profiles, should advantageously be 5% to 15% or 7% to 17% or 9% to 13% greater than the distance of the second side walls of adjacent transverse ribs of the external toothing.

[0018] It is also advantageous if the width of a transverse rib of the external toothing of a drive element is smaller than the distance between the two facing side walls of two adjacent transverse ribs of the external toothing. The difference is advantageously 5% to 20%, preferably 10% to 15%, which means, for example, that the "holes" of the loading ramp's toothing profiles are larger by the said percentage than the width of the transverse ribs of the external toothing of the drive elements. For example, if a toothed belt profile is used for the external toothing of the drive elements, in which the teeth and the gaps between the teeth are each 5 mm, the transverse ribs of the toothing profiles should have a width of 4 mm and the "holes" between these transverse ribs should be 7 mm. This would result in the "pitch" of the external toothing of the drive elements being 10 mm and the pitch of the toothing profiles being 11 mm.This difference, necessary for secure engagement, is explained above and, in this example, applied to a drive element with a diameter of approximately 10 cm. Approximately 10 cm, or more precisely, 97 mm.

[0019] In principle, one would think that the spacing of the transverse ribs of the external toothing of the drive element and the spacing of the transverse ribs of the toothing profile should be the same, as should the pitch (division into transverse ribs and gaps). However, tests have shown this to be undesirable. As stated above, the spacing of the transverse ribs of the toothing profile of the loading ramp should be slightly larger than the transverse rib spacing of the external toothing of the drive element. This is because the deflection of the timing belt around the idler pulley causes a "spreading" of adjacent transverse ribs of the timing belt, which must be taken into account when designing the spacing of adjacent transverse ribs of the toothing profiles.The "gap" between any two adjacent transverse ribs of the tooth profile should also be slightly larger than the width of the transverse ribs of the external toothing of the drive element (in order to be able to access the loading ramp at its lower end, which is on the ground, with the transverse ribs securely interlocking, even when the patient transport device is slightly tilted). Finally, the chamfer described above is also beneficial for the secure engagement of the transverse ribs of the external toothing of the drive element and the transverse ribs of the tooth profile.

[0020] The external toothing of each drive element is expediently designed as a toothed belt, wherein each toothed belt has, in addition to its external toothing, also an internal toothing facing away from it, and wherein each drive element has a roller or a wheel with a toothed circumferential surface for meshing with the internal toothing of the toothed belt.

[0021] The toothed profiles on the loading ramp are expediently designed as racks or toothed plates with transverse ribs on one side. These racks or toothed plates have a material layer that can be defined as a carrier layer, from which the transverse ribs protrude. The carrier layer is fixed to the loading ramp in a shear-resistant manner, which can be achieved using fastening elements such as screws, rivets, etc. Alternatively, the toothed profiles can be glued to the loading ramp. This can be done by first using a double-sided adhesive tape that is thicker than the height of the local unevenness / surface textures of the loading ramp to compensate for profiles or unevenness in the recesses of the loading ramp. The toothed profile is then applied to the double-sided adhesive tape and pre-assembled or pre-fixed.The areas of the loading ramp around and between the adhesive tapes, in which the toothed profiles are to be arranged, are then provided with liquid adhesive, after which the toothed profiles are placed.

[0022] The toothed profiles, or the racks or toothed plates, can also be glued together as individual pieces. It is advantageous if adjacent individual pieces are connected and held together by a tongue-and-groove connection with an undercut. When the loading ramp is folded down when not in use and placed in the vehicle, the toothed profile is separated at the joints of the loading ramp.

[0023] Within the scope of the invention, a transverse rib of both the external toothing of the drive elements and the toothing profiles of the loading ramp does not necessarily mean a continuous projection. Thus, the transverse ribs can be designed as divided projections in the form of, for example, a "row of studs," i.e., individual adjacent studs, or in the form of individual adjacent webs.

[0024] As already mentioned above, the ground-driven patient transport device can be designed in various forms (such as the type shown in US Pat. No. 8,783,392 B2). The embodiment of the wheelchair according to DE 20 2022 100 835 U1 has the advantage that a preferably removable crawler drive is mounted on the backrest and frame of the wheelchair, which can be pivoted between a rest position and a drive position. In the rest position, the crawler drive rests essentially against the back of the wheelchair, with the wheelchair's casters forming contact with the ground.In the drive position, the lower deflection ends of the crawler tracks of the crawler drive are positioned below the contact surface of the wheelchair's rear rollers, thus forming the ground drive for moving the wheelchair along a surface. The ground drive's contact with the surface is achieved by the rolling circumferential surface of a roller, cylinder, or wheel, each of which can act as a deflection element for a crawler track belt. In these cases, the outer side of the belt forms the aforementioned circumferential surface of the drive element rolling on the surface. Likewise, in the drive position of the crawler tracks, the wheelchair can be automatically moved up and down stairs, which is advantageous for transporting patients in stairwells and on curved staircases.

[0025] A hospital chair which can be used advantageously as a patient transport device is provided with the features according to the invention, in addition to a chair having a frame with a seat, a backrest and legs provided with castors and / or swivel castors, and a crawler drive for traveling over one or more steps, e.g. a staircase, with the chair, wherein the crawler drive is provided with a drive module arranged on the frame of the chair, which has two crawler tracks with deflection elements and a crawler belt loop that can be driven in rotation around the deflection elements, a drive unit for the two crawler tracks, a control unit for controlling the drive unit and an operating device that is in communication with the control unit and has manually operable operating elements for entering commands for the control unit.

[0026] For maneuverability, it may be useful that by operating the control elements, the crawler tracks can be driven at different speeds in the same and / or opposite directions by means of the drive unit controlled by the control unit, so that the chair can be steered when driving over, for example, one or more steps of a staircase or on a different type of surface.

[0027] The drive module of the crawler drive of the preferably usable wheelchair has a drive unit by means of which the two crawler tracks equipped with external gearing can be controlled jointly or independently of one another. The control unit provided for this purpose communicates with an operating device with manually operable operating elements for inputting commands to the control unit. By operating the operating elements, the crawler tracks can be driven by the drive unit controlled by the control unit at either the same or different speeds in the same and / or opposite directions, allowing the wheelchair to be steered when traveling over one or more steps of a staircase, for example. This now makes it possible to use the wheelchair even on curved stairs.

[0028] The drive unit, for example, has two drive motors, each of which, if necessary, drives the externally toothed crawler belt loops of the two crawler tracks via a gearbox. Alternatively, the drive unit has a (single) motor that drives both crawler belt loops via a gearbox with two output shafts. By controlling the gearbox, which can be a differential gear, for example, the two output shafts can be moved at the same speed or at different speeds in the same direction or in opposite directions.

[0029] The control device is typically located at the upper end of the backrest, and the upper part of the backrest may be extendable. This places the control device in a comfortable operating position for the paramedic. The communication connection between the control device and the control unit can be wireless or wired. In addition to the two tracked tracks and the control unit, the drive module typically also has a power supply in the form of batteries or accumulators.

[0030] As already mentioned above, the drive module can be moved between a rest position in which the drive module is pivoted towards the rear of the backrest of the chair and the crawler belt loops of the two crawler tracks are aligned substantially parallel to the vertical extent of the backrest of the chair, and a drive position in which the drive module is pivoted away from the backrest of the chair and in which the lower deflection ends of the crawler tracks facing the rollers of the frame of the chair are at a smaller distance from the frame than the opposite upper deflection elements of the crawler tracks.

[0031] In the previously described feature of an advantageous embodiment of the invention, it can further be provided that the lower deflection elements of the crawler tracks are positioned above the contact surfaces of the chair's castors in the rest position of the drive module and below the contact surfaces of the chair's castors in the drive position. Thus, in its drive position, the drive module lifts the wheelchair at its rear end, leaving the rear castors free and allowing the wheelchair to be driven via the crawler tracks for fast, straight-ahead travel or for accessing ramps to, for example, an ambulance or patient transport vehicle. With this design of the drive module and its interaction with the wheelchair, the wheelchair thus has a type of ground drive. Due to the ability to drive the two crawler belt loops in opposite directions, the wheelchair can now rotate on the spot.The external teeth of the track belt loops ensure a certain degree of "adhesion", even when driving on a surface that is not provided with "counter teeth".

[0032] The contact of the crawler tracks with the ground occurs at the lower deflection ends, where the crawler belt loops run around the lower deflection elements / rollers, thus resulting in the situation that the ground drive is provided like a drive roller, the outer side of which is similar to the outer profile of the crawler loop belt.

[0033] If the patient transport device does not need to be designed for climbing stairs, two ground drive rollers with external gearing can be used instead of the crawler tracks. Such ground drive rollers, i.e., drive rollers with external gearing, can also be mounted on a stretcher carriage or on the legs of a wheelchair, without necessarily requiring a crawler track with a looped track.

[0034] In a further practical embodiment of the advantageously usable wheelchair, the operating device can be provided with two manually adjustable operating elements for selecting the drive speed of the two crawler tracks. When both operating elements are actuated for forward travel, the starting movement and speed are controlled with a time delay by the control unit, thus allowing both crawler tracks to be synchronized. Suitable operating elements include slide switches or so-called thumb joysticks for the separate control of both drive motors. To facilitate starting the wheelchair, after an initial operation of both operating elements, a synchronized control of both crawler tracks occurs automatically with a time delay, so that the wheelchair initially moves forward or backward in a straight line.Maneuvering in curves or when reversing (the latter, for example, over a loading ramp) can then be carried out by operating the control elements accordingly.

[0035] With regard to maneuvering when reversing, it is advantageous to ensure that when only one of the two control elements for forward travel is operated, or when both control elements for opposite movements of the crawler belt loops of the two crawler tracks are operated, or when both control elements for reversing are operated, the control unit limits the drive speed of the two crawler tracks to a lower or the same value than, or as, when traveling forward.

[0036] It is also advisable to equip the wheelchair with the track drive only when necessary. This allows the wheelchair to be used both with and without the track drive. The track drive module is therefore removable from the frame. If a wired communication connection is used between the control device and the control unit, this cable must then be disconnected. This can be achieved using plug-in and detachable connectors. Alternatively, a wireless communication connection between the control device and the control unit is also particularly suitable for this case.

[0037] The advantageously usable wheelchair provided with the external toothed drive elements according to the invention can, for example, can be turned on the spot using a thumb joystick, for example (stairs, platform), has a first operating device at the upper end of the backrest and a second operating device on the typically present foot-side carrying and operating handles of the wheelchair, whereby this second operating device can also be operated using a thumb joystick, for example, and is in wired or wireless communication with the control unit, can be moved on curved stairs and can be driven up and down on vehicle loading ramps.

[0038] Intelligent control allows fast straight-line travel when, for example, both thumb joysticks are pressed in the same direction, whereby the drive module accelerates to full speed with a start-up curve / synchronization of both crawler tracks, whereby the start-up curve at low speed and the time delay until the start of acceleration to full speed compensates for the thumb joysticks not being pressed at the same time (timing by the paramedic) when only one thumb joystick is pressed or both thumb joysticks are pressed in opposite directions, that the crawler drive travels at a slow speed, whereby this makes shunting / manoeuvring predictable and intuitive and thus minimizes the risk of accidents.

[0039] The complete crawler drive can be easily docked to and detached from the wheelchair using a quick-release system, which means that the wheelchair can be used either with or without the crawler drive.

[0040] The invention is explained in more detail below using an embodiment and with reference to the drawing.

[0041] In detail: Fig. 1 shows a side view of the situation in which the wheelchair is moved on a staircase with the crawler drive in the drive position, Fig. 2 shows a side view of the wheelchair with the crawler drive in the rest position, Fig. 3 shows a view of the wheelchair from the rear, Fig. 4 shows a side view of the wheelchair when moving across a level with the crawler drive used for ground propulsion, Fig. 5 shows a perspective view (simplified) of an ambulance or emergency medical vehicle with a loading ramp having two strips with toothed profiles, Fig. 6 shows a side view of the situation in which the wheelchair is traveling on the loading ramp, and Fig. 7 shows an enlarged view corresponding to VII of the Fig. 6 .

[0042] In the following, a wheelchair that can be advantageously used within the scope of the invention as a patient transport device with a propulsion drive is described. The interaction of this wheelchair with the transfer system according to the invention is described in the Figs. 5 to 7 shown.

[0043] Two side views of the wheelchair 10 in the two possible operating states of the drive module 12 are shown in the Fig. 1 , 2 and 4 shown. According to Fig. 2 The wheelchair 10 has a frame 14 provided with a seat 16, a backrest 18, and legs 20 on which casters and / or swivel casters 22 are located. The backrest 18 is extendable and has a telescopic bar 24 on which an operating device 26 with, for example, slide switches 28 is located.

[0044] The drive module 12 with a caterpillar drive 30 is located on the back of the backrest 18. The drive module 12 is pivotably or tiltably mounted on the frame 14 of the wheelchair 10 and is located in Fig. 2 in its rest position. In this rest position, the crawler drive 30 has no contact with the ground 32.

[0045] As shown by Fig. 3 As can be seen, the crawler drive 30 has two crawler tracks 34, each of which has two deflection elements 36 (see Fig. 2 ) and a crawler belt loop 38 guided around it. The crawler belt loop 38 can be designed as a preferably ribbed belt (toothed belt) or in the form of a chain.

[0046] The drive module 12 has a drive unit 39 for driving the crawler tracks 34 either at the same speed or at different speeds in the same direction or in different directions. In this exemplary embodiment, the drive unit 39 has a separate drive motor 40 for each crawler track 34, with an electronic control unit 42 being provided for controlling both motors. The operating device 26 is in communication with this control unit 42 (in Fig. 3 indicated by the dashed line 44). The drive module 12 further comprises a power supply unit 46 in the form of a battery or accumulator.

[0047] A typical application for the drive module with wheelchair 10 is in Fig. 1The crawler tracks 34, which can be manually controlled by means of the slide switches 28, allow the crawler belt loops 38 to be driven in the same direction at different speeds as well as in opposite directions. This allows the Fig. 1 The wheelchair 10 can also be maneuvered along a curved staircase, i.e. along a staircase with a "curve". On a level surface (see Fig. 5 ) the crawler drive 30 can be used as a ground drive in that the lower deflection elements 36 of the two crawler tracks 34 are located below the rear running and / or steering rollers 22 of the wheelchair 10, i.e. the wheelchair is raised at the rear when the drive module 12 is in its drive position.

[0048] In the Fig. 1 and 4The inventive detail of the drive module 12 of the wheelchair 10 is shown in an enlarged scale. The drive elements, in this exemplary embodiment in the form of the crawler belt loops 38, have an internal surface with teeth in the form of an internal toothed belt 48 with, for example, trapezoidal projections 50 ("teeth"), which mesh with the deflection elements 36 designed as gears (not shown in detail), of which at least one is driven per crawler track 34. On their outer sides 52, the crawler belt loops 38 each have a further toothed belt 54 with, for example, trapezoidal projections 56 ("teeth"), which form an external toothing 55 with transverse ribs 57. Both toothed belts 48 and 54 are firmly connected to one another, for example by adhesive bonding. The (outer) projections 56 serve in the usage situation of the wheelchair 10 according to Fig. 1 as additional support of the wheelchair 10 on, for example, the front edges 58 of the steps by a type of form fit.

[0049] In the Figs. 5 to 7 a further advantage of the external toothing 55, ie the projections 56 of the crawler belt loops 38, is shown, namely when driving onto a loading ramp 60 of a loading and unloading device 53 of an ambulance or KTW 62. The loading ramp 60, which has a first end 59 for resting on the ground 32 and a second end 61 facing away from the first end 59 on the loading edge of the ambulance / KTW 62, is provided with toothing profiles 64 which are fixed at a distance from the two crawler belt loops 38 of the wheelchair 10 on the loading ramp 60 and have protruding transverse ribs 66. When driving onto the loading ramp 60 with the wheelchair 10, the projections 56 (cross ribs 57) on the outer side 52 of the crawler belt loops 38 mesh with the cross ribs 66 of the toothed profiles 64 of the loading ramp 60 (see the enlarged illustration of area VII of the Fig. 6 in Fig. 7 ).

[0050] The external toothing 55 on the (floor) drive elements of the wheelchair 10, ie on the crawler belt loops 38, in their respective section moving around the lower deflection elements or rollers 36, thus ensure, in addition to potential friction properties of the material on the outer side 52 of the drive elements of the wheelchair 10 when driving on a floor step of a staircase or on the loading ramp according to Figs. 5 to 7 for additional form-lock interaction.

[0051] The design of the transverse ribs 66 described below serves to ensure reliable engagement of the transverse ribs 57 of the toothed belt 54 with the transverse ribs 66 of the toothed profiles 64. Each of these transverse ribs 66 has a first side wall 68 facing the upper second end 61 of the loading ramp 60 and a second side wall 70, which in this exemplary embodiment both protrude essentially perpendicularly from a carrier layer 72 of the toothed profiles 64, from which the ribs 66 protrude. The two aforementioned side walls 68, 70 of each rib are connected to one another via an upper side 74. In the transition region between the first side wall 68 and the upper side 74 of each rib 60, the latter is provided with a chamfer 76 having an inclined surface 78 forming an angle 82 of preferably 25° to 35° with a plane 80 perpendicular to the carrier layer 72.

[0052] In this exemplary embodiment, the transverse ribs 57 of the toothed belt 54 are essentially trapezoidal in shape, with the gap 84 between two adjacent transverse ribs 57 of the toothed belt 54 being complementary to the shape of the ribs. In this exemplary embodiment, the toothed belt 54 also has an internal toothing 86 that meshes with a corresponding and, in particular, complementary external toothing 88 of the idler pulley 36.

[0053] As previously mentioned, the transverse ribs 57 of the external toothing 55 of the toothed belt 54 are trapezoidal. The side walls or side flanks form an angle 92 of, for example, 20° to 30° with a plane 90 running perpendicular to the toothed belt 54.

[0054] The distance (center distance) between adjacent transverse ribs 66 of the toothed profiles 64 is 10% to 30% greater than the center distance between adjacent transverse ribs 57 of the external toothing 55 of the toothed belt 54. This is advantageous in that the next submerged transverse rib 57 of the toothed belt 54 safely enters the gap 94 between two adjacent transverse ribs 66, namely by a side wall or side flank of the said transverse rib 57 on the second side wall 68 of the transverse rib 66. This is in Fig. 7 shown in the area in which the toothed belt 54 tangentially touches the tooth profile 64 or is shortly before tangential contact.

[0055] It should also be noted that the width of a transverse rib 57 of the toothed belt 54 on its outer side is slightly smaller than the gaps 94 between adjacent transverse ribs 66 of the toothed profile 64. The advantage of this is that it is now possible to safely approach the loading ramp 60 even when the wheelchair 10 is slightly tilted. If the floor drive of the wheelchair 10 is then in engagement with the toothed profile 64, the wheelchair 10 should be centered, so to speak, i.e., its direction of travel should be parallel to the extension of the toothed profiles 64.

[0056] For fastening the toothed profile 64 on the loading ramp 60, please refer again briefly to Fig. 7By means of transverse double-sided adhesive tapes 96, in particular, a specific distance between the carrier layer 72 and the surface of the loading ramp 60 is achieved, so that the carrier layer 72 bridges any surface structural irregularities of the loading ramp 60. The space between the loading ramp and the underside of the carrier layer 72 of the toothed profiles 64 is then filled with liquid adhesive 98.

[0057] In the Fig. 5 and 6 Another detail is shown, which will be discussed below.

[0058] When driving the patient transport device 10 into the vehicle 62, care should be taken to ensure that the drive elements 38 are always in contact with the loading ramp 60. If the floor drive is located substantially vertically below the rear wheel of the wheelchair, as in Fig. 6This contact is always present. The situation may be different if, for example, Fig. 2shown, the floor drive is located behind the rear castors of the wheelchair. Such a floor drive, which is in contact with the ground behind said castors and would also raise the rear castors of the wheelchair, would result in the floor drive no longer being available due to a lack of contact with the loading ramp when the rear castors, like the front castors, are already on the floor of the vehicle 62 in the final phase of loading. Therefore, the loading ramp 60 has run-up blocks 97 at its second end 61, via which the floor drive then continues to have contact with the ground and thus the wheelchair can be driven into the vehicle 62 by motor even in the final phase of a loading process. In the exemplary embodiment, the run-up blocks 97 are essentially trapezoidal in shape, and other shapes with drive-up surfaces are also conceivable.The run-up blocks 97 can also have a profile in the form of transverse ribs, but this is not mandatory. The upper surfaces of the run-up blocks 97 should be able to be passed over by the ground drive with a force fit.

[0059] Finally, the possibility of connecting adjacent sections of the toothed profiles 64 by means of a tongue and groove connection 99, as shown in the enlarged illustration of the Fig. 7 can be seen. The tongue and groove connection 99 shown is based on interlocking complementary undercuts and corresponding formations on the mutually facing ends of adjacent parts of the tooth profiles 64. LIST OF REFERENCE SYMBOLS

[0060] 10 Hospital chair, patient transport device 12 Drive module 14 Frame 16 Seat 18 Backrest 20 Legs 22 Castors and / or steering wheels 24 Bar 26 Operating device 28 Slide switch 30 Crawler drive 32 Surface 34 Crawler tracks 36 Deflection elements 38 Crawler belt loop 39 Drive unit 40 Drive motor 42 Control unit 44 Communication connection 46 Energy supply unit 48 Internal toothed belt of each crawler belt loop 50 Projections (teeth) of the internal toothed belt 52 Outside of each crawler belt loop 53 Loading and unloading device 54 External toothed belt of each crawler belt loop 55 External toothing 56 Projection (teeth) of each external toothed belt 57 Cross ribs 58 Front edge of a step 59 First end of the loading ramp 60 Loading ramp 61 Second end of the loading ramp 62 Hospital or ambulance 64 Toothed profile 65 Toothed profile on the loading ramp 66 Cross ribs 68 Side walls 70 Side walls,72 Carrier layer 74 Top side 76 Chamfer 78 Inclined surface 80 Level 90 Level 82 Angle 92 Angle 84 Gap 86 Internal toothing 88 External toothing 94 Gap 96 Double-sided adhesive tape 97 Overrun blocks 98 Liquid adhesive 99 Tongue and groove joint,

Claims

1. Transfer system for transferring a patient into an ambulance or patient transport vehicle, comprising - a patient transport device (10), in particular in the form of a hospital chair, wherein the patient transport device (10) is provided with - a movement drive (30) which comprises motor-driven drive elements (38) such asWheels or rollers or caterpillar drives, - wherein the drive elements (38) have an outer side (52) rolling on a surface for contact therewith, said outer side having external toothing (55) in the form of transverse ribs (57), and - a loading and unloading device (53) for driving over by means of the patient transport device (10), - wherein the loading and unloading device (53) is provided with - a loading ramp (60) and - one or more toothing profiles (64) arranged or formed on and / or at the loading ramp (60) with transverse ribs (66) running transversely to their respective longitudinal extent for meshing with the external toothings (55) of the outer sides (52) of the drive elements (38) of the patient transport device (10).

2. Transfer system according to claim 1, characterized by - that the loading ramp (60) has a first end (59) for resting on a surface and a second end (61) facing away from the first end (59), - thateach tooth profile (64) has a lower support layer (72) from which the transverse ribs (66) project upwards, - that each transverse rib (66) of a toothed profile (64) has a first upstanding side wall (68) facing the first end (59) of the loading ramp (60), a second upstanding side wall (70) facing the second end (61) of the loading ramp (60), and an upper side (74) connecting both side walls (68, 70), and - that each transverse rib (66) is chamfered in the transition region of the second side wall (70) to the upper side (74).

3. Transfer system according to claim 2, characterized in that the chamfer (76) of the second side wall (70) of each transverse rib (66) forms an angle of 20° to 40° or of 25° to 45° or of 30° to 35° with an imaginary plane running perpendicular to the carrier layer (72).

4. Transfer system according to claim 2 or 3, characterized in thatthe second side walls (70) of the transverse ribs (66) of each tooth profile (64) protrude vertically from the carrier layer (72) to the chamfer (76).

5. Transfer system according to one of claims 2 to 4, characterized in that the first side walls (68) of each transverse rib (66) of each toothed profile (64) are free of a chamfer in the transition region to the upper side (74) of the transverse rib (66) and / or run perpendicular to the carrier layer (72) or at an acute or obtuse angle to the carrier layer (71).

6. Transfer system according to one of claims 2 to 4, characterized by - that adjacent transverse ribs (66) of each tooth profile (64) each have a first distance from each other, - that adjacent transverse ribs (57) of the external toothing (55) of each drive element (38) each have a second distance from each other and - that the first distance is 5% to 15% or 7% to 17% or 9% to 13% greater than the second distance.

7. Transfer system according to one of claims 1 to 6, characterized in that adjacent transverse ribs (66) of each toothing profile (64) define a gap (84) between their mutually facing first and second side walls (68, 70) which is wider than the width of the transverse ribs (57) of the external toothing of each drive element (38) and in particular by 20% to 80% or 30% to 70% or 40% to 60% or 45% to 65% wider than the width of the transverse ribs (57) of the external toothing of the drive element (38).

8. Transfer system according to one of claims 1 to 7, characterized in that the external toothing (55) of each drive element (38) is designed as a toothed belt (54).

9. Transfer system according to claim 8, characterized in thateach toothed belt (54) has, in addition to its external toothing (55), also an internal toothing (86) facing away from it, and that each drive element (38) has a roller or a wheel with a toothed circumferential surface for meshing with the internal toothing (86) of the toothed belt (64).

10. Transfer system according to one of claims 1 to 9, characterized in that each drive element 38 is designed as a drivable crawler track (34) with a deflection element (36), preferably in the form of a deflection roller and a toothed belt (54) provided with external teeth for meshing with the toothing profile (64) of the loading ramp (60), wherein the drivable toothed belt (54) movable around the deflection element (36) is provided as contact with a ground and as an outer side rolling on this.

11. Transfer system according to one of claims 1 to 10, characterized in thatthe toothed profile(s) (64) are designed as surface structures formed in and / or on the upper side of the loading ramp (60).

12. Transfer system according to one of claims 1 to 11, characterized in that the loading ramp (60) is designed as a plate or in the form of two webs which are parallel in use, each of which has a toothed profile (64) with transverse ribs (66).

13. Transfer system according to one of claims 1 to 12, characterized in that at the end (61) of the loading ramp (60) facing the rescue or ambulance (62), in extension of the toothed profiles (64) or on the toothed profiles (64), run-up blocks (97) for the drive element (38) are arranged to ensure their contact with the ground when the patient transport device (10) is in the final phase of driving into the rescue or ambulance (62).

14. Use of a toothed profile (64) with transverse ribs (66) running transversely to its longitudinal extent for the loading ramp (60) of a loading and unloading device (53) of an ambulance or patient transport vehicle for driving on by means of a patient transport device (10), in particular in the form of a wheelchair, which has motor-driven drive elements (38) such as wheels or rollers or caterpillar drives, which have an external toothing (55) provided for contact with a substrate, in particular in the form of an outer side (52) provided with transverse ribs (57), by meshing the external toothing (55) of the outer sides (52) of the drive elements (38) of the patient transport device (10) with the toothed profile (64) on and / or on the loading ramp (60).

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