BED, PREFERABLY HOSPITAL OR CARE BED

Abstract

Bed, comprising a lower frame (1) and an upper frame (2) with a supporting surface for a mattress, and where the upper frame (2) is connected to the lower frame (1) so that the upper frame can be raised and lowered in proportion to the lower frame by means of one or more adjusting means (5, 6) driven by an electric motor. In order to prevent squeezing between the upper and lower frame when the upper frame is lowered, the bed is provided with anti squeezing means. These comprise a light source and a receiver positioned in a corner of the lower frame. The light source sends a light beam which follows the lower frame all the way around and runs just above the top side of the lower frame. When the light beam is interrupted the control unit reacts by cutting off the current for the motors.

Claims

1-4. (canceled)

5. A bed comprising: a lower frame equipped with drive wheels, and defining four corners, an upper frame having a supporting surface for a mattress, an adjusting means driven by an electric motor for raising and lowering the upper frame relative to the lower frame, a control unit which can be activated with a controller for controlling the adjusting means, said control unit comprising a bus, and squeezing protection means for preventing anything from being squeezed under the upper frame, said squeezing protection means comprising a light source master means on the top side of a first corner of the lower frame wherein said light source master means include light source and receiver, a first repeater means at a second corner, a second repeater means at a third corner, a third repeater means at a fourth corner, said light source master means being connected to said bus, wherein said light source master means emitting a single first light beam directly at said first repeater means, said first repeater means, upon receipt of said single first light beam, emitting a single second light beam directly at said second repeater means, said second repeater means, upon receipt of said single second light beam, emitting a single third light beam directly at said third repeater means, and said third repeater means, upon receipt of said single third light beam, emitting a single fourth light beam directly at said light source master means; wherein an interruption of any one of said first, second, third or fourth light beams will prevent said fourth light beam reaching said light source master means which is configured to send a signal to said control unit to stop said electric motor.

6. The bed according to claim 5 wherein each of the light source master means, the first repeater means, the second repeater means and the third repeater means includes a respective housing having an opening for transmitting a light beam and an opening for receiving a light beam.

7. The bed according to claim 5, wherein each of the first, second and third repeater means are positioned on the top side of the lower frame.

8. The bed of claim 5 wherein the control unit is further configured to reverse for a time said electric motor to thereby raise said upper frame a distance.

9. The bed of claim 8 wherein said control unit reverses said electric motor when said interruption occurs while the upper frame is being lowered.

10. The bed of claim 6 wherein each of the light source master means, the first repeater means, the second repeater means and the third repeater means includes the respective housing having a respective lens in the opening for transmitting the light beam and a respective lens in the opening for receiving the light beam, wherein a lower part of at least one of said lenses has a matte finish to block disruptive reflections.

11. The bed of claim 6 further including a switch mounted on an upper side of each housing, which when activated when the upper frame is lowered, stops the electric motor.

12. The bed of claim 6 further including a plate in each of the housings which with one end by means of a spring load protrudes through an opening in an upper side of the housing, and when urged into the housing, another end of the plate is brought into the respective light beam and interrupts the light beam.

13. The bed of claim 5 wherein said controller comprises a hand controller.

14. The bed of claim 5 wherein said light source master means is configured to emit said first light beam as a predetermined number, plurality of pulses, said light source master means being further configured to determine when all of said plurality of pulses are detected in said fourth light beam according to predetermined criteria, and to set a bit in a frame on said bus indicating to said control unit that said squeeze protection means is connected.

15. The bed of claim 5 wherein said signal sent to said control unit to stop said electric motor occurs on said bus and comprises setting a bit in a frame on said bus.

16. A bed comprising: a lower frame equipped with drive wheels, and defining four corners, an upper frame having a supporting surface for a mattress, an adjusting means driven by an electric motor for raising and lowering the upper frame relative to the lower frame, a control unit which can be activated with a controller for controlling the adjusting means, and squeezing protection means for preventing anything from being squeezed under the upper frame, said squeezing protection means comprising a light source master means on the top side of a first corner of the lower frame, a first repeater means at a second corner, a second repeater means at a third corner, a third repeater means at a fourth corner, and a detector means near said light source master means which is connected to said electric motor, said light source master means emitting a single first light beam directly at said first repeater means, said first repeater means, upon receipt of said single first light beam, emitting a single second light beam directly at said second repeater means, said second repeater means, upon receipt of said single second light beam, emitting a single third light beam directly at said third repeater means, and said third repeater means, upon receipt of said single third light beam, emitting a single fourth light beam directly at said detector means, so that interruption of any one of said first, second, third or fourth light beams will prevent said fourth light beam reaching said detector means and thus cause said control unit to stop said electric motor.

17. The bed according to claim 16, wherein each of the light source master means, the first repeater means, the second repeater means and the third repeater means includes a respective housing having an opening for transmitting a light beam and an opening for receiving a light beam, further including a switch mounted on an upper side of each housing, which when activated when the upper frame is lowered, stops the electric motor.

18. The bed according to claim 16, wherein each of the first, second and third repeater means are positioned on the top side of the lower frame.

19. The bed of claim 16, wherein the control unit is further configured to reverse for a time said electric motor to thereby raise said upper frame a distance.

20. The bed of claim 17, wherein each of the light source master means, the first repeater means, the second repeater means and the third repeater means includes the respective housing having a respective lens in the opening for transmitting the light beam and a respective lens in the opening for receiving the light beam, wherein a lower part of at least one of said lenses has a matte finish to block disruptive reflections.

Description

[0009] An embodiment for the invention will be explained more fully below with reference to the accompanying drawing, in which:

[0010] FIG. 1, shows a schematic view of a hospital bed,

[0011] FIG. 2, shows a schematic view of the squeezing protection on the bed,

[0012] FIG. 3, shows a table,

[0013] FIG. 4, shows a timing diagram of IR- transmitter and IR-receiver,

[0014] FIG. 5, shows a simplified flow chart of the method of operation of the squeezing protection, and

[0015] FIG. 6 shows a perspective view of a master with an IR-transmitter and receiver.

[0016] The hospital bed shown in FIG. 1 of the drawing comprises a lower frame 1 equipped with drive wheels and an upper frame 2. On the upper frame is mounted an adjustable supporting surface for a mattress, which with actuators can be adjusted to assume various contours. The upper frame 2 is coupled to the lower frame by means of a link mechanism 3,4 at each end. The upper frame can be raised and lowered by two actuators 5,6 connected to the link mechanism. The actuators are linear actuators driven by a low voltage DC-motor of the type described in EP 531 247 B1, EP 647 799 B1 or WO 02/29284 all to Linak A/S. The actuators are connected to a control unit 7 comprising a power supply and a control. The actuators are operated by means of a hand control 8.

[0017] The bed is equipped with a protection against squeezing mounted on the top side of the lower frame 1 and the structure of the squeezing protection is suggested in FIG. 2. In one corner of the lower frame 1 is mounted a master 9 with a IR-transmitter, which sends a light beam directly along and immediately above one of the side members in the lower frame 1 to the adjacent corner, where a slave 10 is positioned, which receives and repeats the signal, and sends it along and immediately above the traverse by the foot of the bed to the adjacent corner, where a corresponding slave 11 is positioned, which sends the light on along the other side member of the lower frame to yet another slave 12 in the adjacent corner, which finally sends the signal back to the master 9 wherein a receiver is positioned. If the IR-signal is interrupted during its trip around the lower frame, a signal for stopping the actuators is sent to the control unit, and the control unit obstructs lowering the upper frame further, while it is still possible to raise the upper frame if it is found necessary.

[0018] In FIG. 6 of the drawing a perspective view of a master 9 comprising an IR-transmitter and receiver is shown. The IR-transmitter sends a light beam through a lens/filter also known as the window 9a. The slaves 10-12 consist of a corresponding housing, but comprise a receiver/repeater, which receives and sends the light beam on until it returns to the master 9, where the light beam enters the window 9a. In order to ease the assembly process the direction of the light beam is indicated with arrows on top of the housings. In order to block disruptive reflections from the top side of the lower frame the lower part of the lens/filter can have a matt finish 9c. As a matter of form 9d indicates a screw hole for mounting on the lower frame.

[0019] The control unit can comprise a bus, to which the various electric units such as actuators, hand controls, control panels etc. can be connected. The master 9 of the squeezing protection can be connected to the bus correspondingly. For initiating the squeezing protection the master transmits six IR-impulses with 38 kHz modulation, and all six signals must be received and be at least 400 s in order to be accepted. The master subsequently waits for a RESERVED 1-frame in the bus system and when detected, bit 30 is set to indicate that the squeezing protection system is connected to the control unit. Bit 31 is set, merely, if one of the received IR-impulses is below 400 s. Timing diagram for IR-transmitter and IR-receiver is incidentally shown in

[0020] FIG. 3. The control unit will stop a potential lowering of the upper frame if the system sets bit 31, cf. diagram FIG. 4. A simplified flow chart of the method of operation of the squeezing protection appears from FIG. 5 and this flow chart speaks for itself.

[0021] It is not very likely that something will get squeezing between the upper frame 2 and the upper side of the housings which constitute the master 9 and the slaves 10-12 without the light beam being interrupted. But to shut out the possibility, a switch for stopping the actuators if the upper frame is lowered can be positioned on the upper side of the master 9 and the slaves 10-12. Alternatively a spring loaded plate, guided in the housings and protruding through an opening in the upper side can be located in the housings of the master and the slaves 10-12. If the plate is pressed downwards it is pushed in the course of the light beam and interrupts said light beam. The spring load will see to that the plate of its own again is pulled upwards and away from the course of the light beam when released.

[0022] The invention thus brings about a bed with an extensive protection against squeezing all the way around it.