Patient support apparatus with dual control system of trundles

Abstract

The present invention relates generally to patient support devices in health care and care facilities having casters attached to a base frame or chassis of the patient support device, and in particular to the use of servomotors to double control such casters. The proposed technical solution discloses a bed that includes a patient surface articulating platform that may have a platform section, the articulating platform defining a support surface for a mattress, which in turn defines a patient support surface. The bed further includes an upper frame supporting the articulated platform, a lifting mechanism, which may be in the form of a scissor mechanism or a telescopic column or any other lifting mechanism suitable for a medical institution bed, a base frame, i.e., a chassis supported by a plurality of casters for movement relative to a support surface, such as a floor. The trundles are fixed to the bottom frame through pins. The chassis also includes an actuation pedal of a central control mechanism of the casters. An actuation pedal of a central control mechanism of the trundles mechanically actuates the trundles when rotated to a braked position (lower position), an unbraked position (upper position), or a travel position (intermediate position). The bed trundles may also be electrically controlled by motors, preferably servomotors, hydraulic motors, electric motors, or any other known motors suitable for use with medical institution beds. The presented embodiments preferably connect two types or methods of caster control, i.e., mechanical control of the caster and simultaneous electrical control of the caster, without any necessary signal or indication of in which manner the caster is actuated, and also without switching or positioning the actuation pedal of the central control mechanism of the caster to any intermediate position.

Description

Technical Field

[0001] The present invention relates generally to patient support devices in healthcare and nursing facilities having castors attached to a base frame or chassis of the patient support device, and particularly to the use of servo motors to dually control such castors. Prior art

[0002] The prior art recognizes that patient support devices used in medical and nursing facilities include castors that enable such patient support devices to be moved from an operating room to an intensive care unit, or between various hospital departments and rooms. Such patient support devices are, for example, hospital beds, cots, stretchers, examination chairs, or other suitable devices for use in health care facilities, which will hereinafter be referred to as beds.

[0003] Medical institution beds are usually equipped with caster devices and are designed to be moved from one position to another or otherwise handled in a room. During the movement of the bed, it is desirable to have free-rolling casters. On the contrary, when the desired position is reached, brakes are applied to the casters to keep the bed in a selected position. The casters can rotate around a horizontal axis as well as a vertical axis, which allows the bed to roll and turn between various positions. Medical institution beds usually have four casters, and some beds may be equipped with a fifth caster. This fifth caster is an additional auxiliary caster for easier operation of the bed. The fifth caster can be positioned under the bed, in the middle of the chassis, and can usually be actuated and driven separately by its own drive. Typically, the fifth caster is a caster and a driven caster in a parallel direction, which supports easier movement and operation of the bed.

[0004] Some beds in the prior art are equipped with four separate brake mechanisms and / or steering lock mechanisms and four separate brake pedals or actuation pedals, each brake pedal or actuation pedal being associated with only one of the four castors. Later, for safety reasons, central control mechanisms began to be used with beds in medical institutions. At least one actuation or control pedal of the central control mechanism is positioned anywhere on the chassis or any of the castors and controls the brakes of all castors simultaneously. Preferably, the bed is equipped with more than one actuation or control pedal, which are positioned on the chassis to control the movement, braking or steering lock of the castors from any side of the bed, where the caregiver can stand on the above-mentioned side of the bed at a given moment.

[0005] Typically, the central control mechanism has three positions, ie the actuating pedal of the central control mechanism can be positioned:

[0006] - Lower position, when all castors are blocked in rotation both about the horizontal axis and about the vertical axis. This position is called "braked".

[0007] - Upper position, when all castors can freely rotate about their horizontal and vertical axes, the bed can move freely in all directions. This position is called "unbraked".

[0008] - Intermediate position, when one or two casters are locked in a preselected position about the vertical axis and the other casters are free to rotate about the horizontal and vertical axes. This position is called the "ride" or straight direction of movement.

[0009] The above-specified central control mechanism can be controlled mechanically or electronically. When the patient is supported on the bed, it is necessary to make it easier to manipulate and operate the bed, and the fifth caster begins to be added to the chassis of the bed. The fifth caster can also be mechanical or equipped with an electric motor, which actuates and / or brakes the caster, or unfolds and / or retracts the caster to be used. The fifth caster with an electric motor has its own electric control mechanism for the engagement and movement of the caster. In the case where the medical institution bed is equipped with such a fifth caster, the bed controller needs to include an indication component or mechanism, which indicates that the other casters on the bed are in a "braking" or "unbraking" position, so that the caregiver can safely control the fifth caster and move the bed. In the case where the bed controller or control unit of the bed lacks such an indication mechanism, if the other casters are in the "unbraking" position, if the caregiver needs to move the bed to avoid any damage to the bed or damage to the patient's health, he needs to physically check the bed. This type of solution for maneuvering and moving the bed is inconvenient because it requires two completely separate and mutually independent systems to control the four castors mounted in the bed's chassis and also to control the fifth castor. This technical solution increases the weight of the bed as well as the production costs and the overall complexity of production.

[0010] At present, there is a trend to control the bed casters in a remote manner. This is usually convenient when the bed is equipped with a fifth caster. On the contrary, another trend is to tend to make the production of the bed cheaper and easier to operate. This trend is supported by the patent US 8365353B2 of TENTE, which claims casters with electric motors, which means that each caster installed in the bed frame has its own electric motor. These casters are remotely controlled by a controller, but in the event of voltage loss, it is impossible to mechanically brake the bed and lock it safely in one position, or on the contrary, unlock or release the casters to move the bed freely. Another disadvantage of this solution is that the economic requirements are high and an external power supply is required on the bed, for example, in the form of a battery arranged on the bed frame or directly arranged in the casters. The above-mentioned disadvantages result in a very low chance level of these casters being used with beds in medical institutions.

[0011] Another similar technical solution known in the prior art is patent US8701229B2 of Stryker. The patent discloses a mechanical switch assembly for a mechanical or electrical central control mechanism of casters. The bed of a medical institution includes a central control pedal or a central actuation pedal, which is roughly located in the middle of the bed frame. The central control or actuation pedal mechanically actuates four casters at the same time and operates all casters to all positions, i.e., braking, unbraking, and straight motion direction (travel). The central control pedal can be mechanically turned, and the mechanical central control can be switched to the electrical central control by a switch. The change of the switch position is sensed by a sensor in the mechanical switch. The mechanical central control of the casters is constructed in one position of the pedal, and the electrical central control of the casters is constructed in another position of the pedal. When the caregiver can choose how the braking and movement of the casters will be controlled and operated, this central control mechanism represents a certain progress in the central control logic. The disadvantage can be recognized in the fact that the caregiver must always find out whether the central control mechanism is actuated for mechanical control or electrical control. If the electrical central controller is activated for operation, the mechanical central controller cannot be used unless the control pedal is switched manually (mechanically) and vice versa, and the switch needs to be signaled in the bed controller.

[0012] Another close prior art is disclosed in another patent US10806653B2 of Stryker. The disclosed patent system uses manual mechanical and electrical central control of casters, but the technical solution is very different from the central dual control system of casters disclosed by the applicant in this article. The bed in the above patent includes a base frame, which includes an electric motor and a connecting rod assembly to which an actuating pedal is attached. The actuating or control pedal operates the mechanical control of the casters, and the electric motor operates the electrical control of the casters, however, only when the actuating pedal of the mechanical control of the casters is always positioned in the initial middle position. If the bed is mechanically braked and the actuating pedal is not in the initial middle position, the electrical control of the casters cannot be engaged, and vice versa. The electrical control of the casters cannot be used without switching the actuating pedal to the initial middle position. Therefore, the caregiver always physically checks the position of the actuating pedal to select the mode of caster control.

[0013] For the reasons stated above and the disadvantages disclosed, it is desirable to develop a structurally simpler, faster and safer central control mechanism for castors which can be used dually for mechanical central control of castors as well as electrical central control of castors without requiring any physical check or requiring any signal or indication which control mode is currently activated and therefore available for operation. The caregiver does not have to consider which control mode is selected and can fully concentrate on giving care to the patient. In addition, safe operation of the bed is increased. Summary of the invention

[0014] The technical solution disclosed in this article solves the above-mentioned substantial deficiencies of the existing known technical solutions. The technical solution relates to patient support equipment in medical facilities, such as hospital beds, cots, stretchers, medical examination chairs and any other equipment suitable for use in medical facilities, hereinafter referred to as beds, which have a bed base with a central dual control mechanism with castors.

[0015] A new and innovative caster assembly is disclosed in international patent application WO 2022068978 filed by the same applicant, which is hereby incorporated in its entirety herein, and relates to a triple cam comprising three different cams, which allows the caster to be controlled using much less force than that required to control existing conventional casters. A new and innovative caster assembly is also disclosed in international patent application WO 2021223782 filed by the same applicant, which is hereby incorporated in its entirety herein, and relates to a caster comprising a bidirectional band brake.

[0016] Referring to the invention content disclosed in this article, the technical solution of the new invention proposed in this article eliminates the need to select the caster control method, that is, eliminates the necessary selection of only mechanical control or only electrical control, which always requires a mandatory signal or indication on the bed controller or any other part of the bed that the control method for controlling the casters is activated, that is, if mechanical control can be used to control the casters, or electrical control can be used to operate the casters.

[0017] The proposed technical solution discloses a bed, which includes a patient surface articulated platform, which may have a platform section, and the articulated platform defines a support surface for a mattress, which in turn defines a patient support surface. The bed further includes an upper frame supporting the articulated platform, a lifting mechanism, which may be in the form of a scissor mechanism or a telescopic column or any other lifting mechanism suitable for a bed in a medical institution, and a base frame, i.e., a chassis, which is supported to move relative to a support surface (e.g., a floor) by a plurality of casters. The casters are fixed to the chassis by pins. The chassis also includes an actuating pedal of a central control mechanism of the casters. The actuating pedal actuates two casters, which are positioned at the head end or foot end of the chassis and are connected by a control shaft with a hexagonal cross-section, or actuates all four casters, which use a connecting rod, which connects two control shafts with a hexagonal cross-section, thereby connecting the casters to the head end and foot end of the bed. When the actuation pedal of the central control mechanism of the caster is rotated to a braking position (lower position), an unbraking position (upper position) or a travel position (intermediate position), the actuation pedal mechanically actuates the caster.

[0018] The bed casters can also be electrically controlled by motors, preferably servomotors, hydraulic motors, electric motors or any other known motors suitable for use with beds in medical institutions. The motors can be positioned on a connecting rod or control shaft of a central control mechanism having a hexagonal cross section connecting at least two casters.

[0019] The proposed embodiment preferably connects two types or methods of caster control, namely mechanical control of the caster and simultaneous electrical control of the caster, without any necessary signaling or indication of which mode is activated, and also without the need to switch or position the actuating pedal of the central control mechanism of the caster to any intermediate position. The motor is fixed to the connecting rod so that the caster can be mechanically controlled by the actuating pedal of the central control mechanism of the caster, as well as electrically controlled by the motor in parallel. Therefore, the presented embodiment of the central control mechanism is completely dual. In the case of mechanical control of the caster, the motor is readjusted due to its internal configuration that provides the least resistance, and conversely, in the case of electrical control of the caster, the power is transmitted to the connecting rod of the central control mechanism of the caster, which displaces the position of the actuating pedal or control shaft of the central control mechanism. The control shaft connecting the casters can preferably replace the individual actuating pedals of the individual casters.

[0020] The motor, which is preferably a servomotor, is designed to have sufficient force when activated and, conversely, to move the internal servomotor assembly with minimal mechanical resistance when deactivated. A servomotor of this design, described in detail below, allows dual control of the castor.

[0021] The servomotor comprises a cogwheel and a pinion. The combination of the cogwheel and the pinion located in the servomotor enables dual control of the castors, which means that all castors are mechanically or electrically controlled regardless of the position of the actuating pedal of the central control mechanism of the castors. A toothed wheel, which means that the cogwheel and the pinion move relative to a rack, which comprises a plurality of rack protrusions on the bottom side of the rack, and the servomotor is fixed to the connecting rod of the central control mechanism of the castors via these rack protrusions. The internal arrangement or construction of the servomotor may also use another type of transmission device, such as a chain transmission device or a cogwheel / toothed belt, etc. Compared with other types of transmission devices, the embodiment of the structure using cogwheels and pinions is preferably the most suitable and has the least trouble.

[0022] The servomotor further comprises a position sensor, which senses the position of the cogwheel / toothed wheel, which refers to the position of the cogwheel and the pinion. The position sensor comprises two mechanical micro switches. The micro switch has two positions, namely the closed and open positions. The micro switch transmits information about four positions, and for dual control, it is necessary to have information about three basic positions, namely the braked, unbraked and travel (straight motion direction) positions. The intermediate position can preferably be used as the fourth position, which means that the servomotor is placed in an uncertain position and is not placed in any defined position, namely the braked, unbraked and travel (straight motion direction) positions. Other types of position sensors can also be used, such as optical sensors, magnetic sensors, Hall sensors, etc.

[0023]

[0006] Various advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.

[0024] List of Figures

[0025] Various advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings:

[0026] Figure 1 The arrangement of the castors on the bed frame is shown, excluding the base frame which is not shown, and the detailed attachment of the servomotors for the central control of the castors.

[0027] Figure 2 A detailed view of the internal arrangement of a servomotor is schematically shown.

[0028] Figure 3 An exploded view of a servo motor is shown.

[0029] Figure 4 A chassis with a servo motor is shown.

[0030] Figure 5 Detailed view showing the position of the servo motor.

[0031] Figure 6 An exploded view of a servo motor is shown.

[0032] Exemplary Embodiments of the Invention

[0033] A patient support device such as a hospital bed, cot, stretcher, examination chair or other suitable device for use in a health care facility (hereinafter referred to as a bed) includes a chassis with casters to easily move the bed to a desired position. Figure 1A detailed view of a base frame 1 with castors 2 and the entire central dual control system 3 of the castors is schematically shown. The castors 2 may be conventional castors, however preferably these castors 2 comprise a triple cam as disclosed in international patent application WO2022068978 filed by the same applicant, which is hereby incorporated in its entirety. The base frame 1 of the bed may comprise another type of castor 2 comprising a bidirectional band brake as disclosed in international patent application WO 2021223782 filed by the same applicant, which is hereby incorporated in its entirety, and this castor may also comprise the triple cam as described above.

[0034] The central dual control system 3 of the castors comprises a control shaft 5 with a hexagonal cross section, which connects two opposing castors at the head end or foot end relative to the base frame of the bed. In a preferred embodiment, a connecting member 6 is located in the middle of the control shaft 5, attached to the control shaft 5 at one end and to one end of a connecting rod 7 at the other end. The other end of the connecting rod 7 is connected to another control shaft 5 via a second connecting member 6, which connects the second pair of castors 2. In another embodiment, the connecting member 6 can be positioned anywhere on the control shaft 5. In a preferred embodiment, the motor 8 is located in the middle of the connecting rod 7 relative to the base frame 1. It should be noted that the motor 8 can be located anywhere on the connecting rod 7, or anywhere on at least one of the control shafts 5.

[0035] The central dual control system 3 of the castors is actuated mechanically by an actuation pedal 4 or remotely by a remote control (not shown) attached to the support plate, side rails or headboard or footboard via a cable or wirelessly. The remote control can be directly connected to the bed 8 or control unit (not shown). The remote control is not shown in the picture, but it is currently a conventional standard component of many types of beds. Figure 1 A part of a chassis 1 with castors 2 is shown, which are coupled via a control shaft 5, which preferably has a hexagonal cross section. At least one actuating pedal 4 is located at one end of the control shaft 5. The actuating pedals 4 can be arranged radially on opposite sides of the control shaft 5, or can be located in the middle of a connecting rod 7. By actuating at least one actuating pedal 4, the control shaft 5 turns and changes the position of the other actuating pedal 4 on the opposite end of the control shaft 5. Actuation of at least one actuating pedal 4 causes a transmission of movement on the connecting rod 7, which is coupled to the second control shaft 5 via a connecting member 6, and thus causes the operation of the second pair of castors 2 on the opposite end of the chassis 1. This mechanical control of the central dual control system 3 of the castors 1 can be operated using an actuating pedal 4 on either side of the chassis 1.

[0036] In a preferred embodiment, a motor 8, preferably a servomotor, is located in the middle of the connecting rod 7. It should be noted that the motor 8 can be arranged anywhere on the connecting rod 7. The servomotor 8 is fixed to the connecting rod 7 at the point of the protrusion 9 on the connecting rod 7. The servomotor 8 operates the connecting rod 7, which then operates the caster 2 by remotely positioning the caster 2 to three positions by a remote control. The servomotor 8 can be controlled by the remote control via a cable or wirelessly using a wireless controller. It should be noted that the servomotor 8 can be replaced by any electric motor, hydraulic motor or any other known motor suitable for operating a bed in a medical institution. The central dual control system 3 of the caster can be operated (or actuated) in parallel mechanically by an actuating pedal 4 or electrically by an electric motor 8, which means that dual operation is possible.

[0037] Figure 2 The motor 8 and its internal mechanical part 10 are shown, which is operated by the motor 8 and the internal transmission device, which enables the dual operation and actuation of the central dual control system 3 of the castor 2. Figure 2 The detailed arrangement of the servomotor 8 including the rack 13 is shown. The rack protrusion 14 is visible on the bottom side of the rack 13. The rack protrusion 14 forms a groove that engages with the protrusion 9 of the central dual control system 3 of the link 7 of the castor 2. This structure forms a mechanical connection between the link 7 and the servomotor 8. The pinion 12 of the servomotor 8 interlocks with the cogwheel 11 that operates the rack 13, and a higher transmission number is achieved through the rack 13. This internal mechanical part 10 of the servomotor 8 can operate and control the various positions of the castor 2 in a dual manner. This means that the link 7 of the central dual control system 3 of the castor 2 is operated and controlled by the servomotor 8, so that the castor 2 is positioned in a position of braking, unbraking or straight motion direction (travel), or manually using the actuating pedal 4 and the link 7 of the central dual control system 3 of the castor 2, so that the castor 2 is positioned in a position of braking, unbraking or straight motion direction (travel). The above two ways can be operated in parallel at the same time without returning any component to the initial intermediate position. Both mechanisms of the dual control can be operated from any position where the central dual control system 3 of the castor 2 is located.

[0038] Figure 3An exploded view of a servomotor 8 is shown, comprising a cogwheel 11, which is in contact with a pinion 12 of the servomotor 8, which by using the cogwheel 11 moves a rack 13. The rack 13 comprises rack projections 14 on the bottom side of the rack 13. The rack projections 14 form openings on their bottom side, through which the servomotor 8 is fixed to the connecting rod 7 of the central dual control system 3 of the castor 2. The fixing of the connecting rod 7 is not shown. The lateral sides of the bracket 13 comprise two bottom holes 18 for micro switches and two upper holes 19 for micro switches, which engage two micro switches: a bottom micro switch 16 and an upper micro switch 17. The two micro switches 16 and 17 signal or indicate the position of the internal mechanical part 10 of the servomotor 8, depending on the combination of the on / off states of the micro switches 16 and 17. The micro switches 16 and 17 are located on a printed circuit board 15, on which the entire control logic of the servomotor 8 is located. It should be noted that the control logic of the servomotor 8 can be analog or digital, however, the type of logic is not the subject of the invention in this context.

[0039] Figure 4 The position of a servomotor 8 relative to the chassis 2 is shown, while the servomotor 8 is fixed to a control shaft 5 having a hexagonal cross section, which operates the castors 2 and couples two oppositely positioned castors 2 together. Figure 4 It is clearly shown that the base frame comprises four castors 2, while two opposing castors 2 at the head end of the bed and two opposing castors 2 at the foot end of the bed are connected to the connecting rod 7 of the central dual control system 3 of the castors 2 via a connecting member 6 on a control shaft 5 with a hexagonal cross section. The connecting rod 7 of the central dual control system 3 of the castors 2 connected to the control shaft 5 transmits the movement of one pair of castors 2 to the other pair of castors 2. One pair of castors 2 is operated and controlled by an actuating pedal 4, preferably by a plurality of actuating pedals 4, while the other pair of castors 2 is remotely operated by using a servomotor 8 operated by a remote control (not shown). The remote control can be located anywhere on the side rails, bed frame or headboard or footboard of the bed and connected to the servomotor 8 by a cable. It should be noted that in another embodiment, the remote control can communicate wirelessly with the servomotor 8 via wifi, bluetooth or any other wireless technology (not shown). The servomotor 8 is preferably a rotary servomotor, in which the outlet movement of the servomotor 8 is rotational and the internal mechanical part 10 of the servomotor 8 moves along the axis of the toothed section 21.

[0040] Figure 5 Two views of a portion of a chassis 1 are shown. The left figure shows a castor 2 attached to a control shaft 5 having a hexagonal cross section, which comprises a connecting member 6 located centrally relative to the control shaft 5. The connecting member 6 is coupled at its opposite ends to a link 7 of a central dual control system 3 of the castor 2. A servomotor 8 is positioned on the control shaft 5 next to the connecting member 6. Figure 5 Only a part of a servomotor 8 with a toothed section 21 is shown. The right view also shows a servomotor 8 with a toothed section 21. In this embodiment of the servomotor 8, an internally rotating toothed section 21 is used instead of the rack 13. This toothed section 21 is directly attached to the control shaft 5 with a hexagonal cross section. The toothed section 21 includes holes 18 and 19 to operate the micro switches 16 and 17.

[0041] Figure 6 An exploded view of a rotary servomotor 8 is shown. The servomotor 8 comprises an inner mechanical part 10 of the servomotor 8, a pinion 12, a holder 22, a cogwheel 11, a printed circuit board 15 with micro switches 16 and 17, a toothed section 21 with holes for connecting a control shaft 5 with a hexagonal cross section, and holes 18 and 19, and micro switches 16 and 17. The entire servomotor 8 is located under a housing 20 of the servomotor 8. The toothed section 21 comprises a hexagonal opening which engages the control shaft 5 with a hexagonal cross section. Figure 6 Also shown are holes 18 and 19 in the toothed section 21 for sensing the position by means of micro switches 16 and 17 , thereby defining the position of the control shaft 5 with hexagonal cross section, which is coupled and operates the castor 2 .

[0042] Reference numerals

[0043] 1. Base frame

[0044] 2. Casters

[0045] 3. Central dual control system (of casters)

[0046] 4. Actuating pedal (central control mechanism)

[0047] 5. Control shaft (with hexagonal cross section)

[0048] 6. Connecting components

[0049] 7. Connecting rod

[0050] 8.Servo motor (motor)

[0051] 9. Protrusion (to fix the servo motor)

[0052] 10. Internal mechanical parts of servo motor

[0053] 11. Cogwheel

[0054] 12. Small gear

[0055] 13. Rack

[0056] 14. Rack protrusion (for attachment to connecting rod)

[0057] 15. Printed Circuit Board (PCB)

[0058] 16. Bottom micro switch

[0059] 17.Upper micro switch

[0060] 18. Bottom hole (of micro switch)

[0061] 19. Upper hole (of micro switch)

[0062] 20. Encapsulation

[0063] 21. Toothed section

[0064] 22. Retaining parts

Claims

1. A patient support device with a central dual control system (3) for castors, comprising two pairs of castors (2), said castors having at least one actuating pedal (4) and at least one remote control, wherein: Two opposing castors are always connected via a control shaft (5) with a hexagonal cross section, wherein the two control shafts (5) with a hexagonal cross section are connected to each other via a connecting member (6) to a connecting rod (7) of a central dual control system (3) of the castors (2), a servomotor (8) being positioned on the connecting rod (7), characterised in that the servomotor (8) comprises a printed circuit board (15) with micro switches (16, 17) and internal mechanical components (10), a pinion (12), a cogwheel (11) and a rack (13), the rack comprising a rack protrusion (14) on its bottom side for attachment to the connecting rod (7), wherein the lateral side of the rack comprises a bottom hole (18) on the bottom side, and at least one upper hole (19) on the upper side.

2. Patient support device with central dual control system (3) of castors according to claim 1, characterized in that The servomotor (8) comprises a pinion (12), a holder (22), a cogwheel (11), a printed circuit board (15) with at least one microswitch (16, 17), and a toothed section (21) with at least one hole (18, 19) for at least one microswitch (16, 17).

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