WO2011107763A1

WO2011107763A1 - Obstruction protection apparatus

Info

Publication number: WO2011107763A1
Application number: PCT/GB2011/050201
Authority: WO
Inventors: Sean Mccarroll
Original assignee: Connexions (Uk) Plc
Priority date: 2010-03-04
Filing date: 2011-02-04
Publication date: 2011-09-09
Also published as: GB201003617D0; GB2478412A; GB201103380D0

Abstract

An obstruction protection apparatus comprises a lift mechanism (106), an electrical motor (110) coupled to the lift mechanism (106) for translating the lift mechanism (106) from a first end position to a second end position, and a control unit (114). The control unit (114) is arranged to determine when translation of the lift mechanism (106) is being obstructed by an obstruction, and to halt operation of the lift mechanism (106) in response to detection of the obstruction.

Description

OBSTRUCTION PROTECTION APPARATUS

[0001] This invention relates to an obstruction protection apparatus, particularly but not exclusively, for furniture that comprises a deployable object concealed within an item of furniture when the object is stowed. The object can be any suitable item, for example a media device, such as a television or any other display device, or a compact disc player or a docking station for a digital media player. This invention also relates to an item of furniture comprising an obstruction protection apparatus, for example a bed.

[0002] It is known for a television to be stored within an item of furniture, for example, a footboard of a bed or a so-called Ottoman. In relation to beds, the television is coupled to an electromechanical lift mechanism and can be moved by the lift mechanism from a stowed state within the footboard of the bed, where the television is concealed, to a deployed state, where the television is substantially outside the footboard and exposed so as to be visible and hence viewed.

[0003] During deployment or stowing of the television, the lift mechanism rises or lowers in order to bring the television to the deployed or stowed state, respectively. Typically, the lift mechanism is electrically powered, a first microswitch being appropriately located within the footboard and used to determine when the lift reaches a fully deployed position, and a second microswitch also being appropriately located within the footboard and used to determine when the lift reaches a fully stowed position.

[0004] In this respect, the first and second microswitches are used by a control unit as inputs in order to determine when to stop supplying drive current to an electric motor that drives the lift mechanism. Consequently, when the control unit is supplying drive current to the electric motor in order to deploy or stow the television, the drive current is continuously supplied until the deployed or stowed position is reached as signalled by one of the microswitches in response to actuation thereof.

[0005] In the event that the television and/or the lift mechanism is obstructed during deployment or stowing, the electric motor experiences an unexpected resistance to motion that can result in the electric motor burning out and/or damage to the obstruction. In a particularly undesirable circumstance, the obstruction can be a part of the human or animal body. [0006] According to a first aspect the present invention, there is provided an obstruction protection apparatus comprising: a lift mechanism for an item of furniture; an electrical motor coupled to the lift mechanism for translating the lift mechanism from a first end position to a second end position; and a control unit; wherein the control unit is arranged to determine when translation of the lift mechanism is being obstructed by an obstruction, and to halt operation of the lift mechanism in response to detection of the obstruction.

[0007] The apparatus may further comprise a translation progress detector operably coupled to the lift detector in order to detect obstruction of the lift mechanism.

[0008] The obstruction may be between the first end position and the second end position.

[0009] For the avoidance of doubt, an obstruction should be understood to be broader than an object inserted that impedes translation of the lift mechanism and can include a force applied to the lift mechanism when travelling to the stowed state, thereby impeding normal operation of the lift mechanism.

[0010] The control unit may comprise a current sensor in order to measure a drive current being drawn by the electric motor.

[0011] The control unit may be arranged to use the determined drive current in order to identify an event corresponding to the lift mechanism being obstructed.

[0012] The control unit may be arranged to determine when the electric drive current does not conform to a predetermined criterion associated with substantially unfettered translation of the lift mechanism.

[0013] The predetermined criterion may be evaluated with respect to a threshold value corresponding to a predetermined current value.

[0014] The control unit may be coupled to a translation progress detector arranged to monitor translation of the lift mechanism and to generate an error signal in response to the lift mechanism being impeded from translating from a first predetermined location to a second predetermined location. [0015] The translation progress detector may comprise an array of progress detecting devices.

[0016] The array of progress detecting devices may disposed linearly; the array of progress detecting devices may comprise a pair of neighbouring progress detecting devices; and impediment of the translation of the lift mechanism may be detectable in response to progress of the lift mechanism not being detected within a predetermined time period by a first of the neighbouring progress detecting devices after detection of progress of the lift mechanism by a second of the neighbouring progress detecting devices.

[0017] The array of progress detecting devices may be an array of switching devices and/or sensor devices.

[0018] The translation progress detector may comprise a rotation detector arranged to generate an output signal in response to rotation of the electric motor.

[0019] The rotation detector may comprise a toothed wheel coupled to the electric motor and a sensor device arranged to respond to rotation of the toothed wheel.

[0020] The sensor device may be an electromagnetic radiation sensor. The sensor device may be a magnetic sensor.

[0021] The control unit may be coupled to a presence detector device arranged to detect a presence of an object within an area being monitored by the presence detector device, and to generate an output signal in response to detection of the object.

[0022] The presence detector may be arranged to provide an area through which an intended object can translate without detection thereof.

[0023] The presence detector device may be a light curtain device.

[0024] The control unit may be arranged to translate the lift mechanism in an opposite direction of travel to a direction of travel when the lift mechanism is obstructed; the translation in the opposite direction of travel may be initiated following the obstruction being detected. [0025] The translation in the opposite direction of travel may be for a predetermined period of time or distance.

[0026] According to a second aspect the present invention, there is provided a footboard for a bed comprising the obstruction protection apparatus as set forth above in relation to the first aspect of the invention.

[0027] The footboard may further comprise: a closable aperture arranged to allow a media device to pass when open.

[0028] According to a third aspect the present invention, there is provided a bed comprising the obstruction protection apparatus as set forth above in relation to the first aspect of the invention.

[0029] According to a fourth aspect the present invention, there is provided an item of furniture comprising: a housing, the housing having a closable opening for passage of a media device therethrough; a lift mechanism disposed within the housing for translating the media device; an electrical motor coupled to the lift mechanism for translating the lift mechanism from a first end position to a second end position; and a control unit; wherein the control unit is arranged to determine when translation of the lift mechanism is being obstructed by an obstruction, and to halt operation of the lift mechanism in response to detection of the obstruction.

[0030] It is thus possible to provide an obstruction protection apparatus that prevents damage to the electric motor and/or an obstruction that hinders or impedes translation of a lift mechanism.

[0031] At least one embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of a bed footboard comprising a lift mechanism and an electric motor;

Figure 2 is a schematic diagram of the bed footboard of Figure 1 from a different viewing angle and having a television in a deployed state; Figure 3 is a schematic diagram of an obstruction protection apparatus coupled to a lift assembly via an electric motor and constituting an embodiment of the invention;

Figure 4 is a schematic diagram of a control unit of Figure 3 in greater detail;

Figure 5 is a flow diagram of a method of operation of the apparatus of Figure 3 and constituting a further embodiment of the invention;

Figure 6 is a graph of electrical current vs. time during normal operation of a lift mechanism in respect of a first direction;

Figure 7 is a graph of electrical current vs. time covering a period of time during which an obstruction event takes place in respect of the first direction;

Figure 8 is a graph of electrical current vs. time during normal operation of a lift mechanism in respect of a second direction;

Figure 9 is a graph of electrical current vs. time covering a period of time during which another obstruction event takes place in respect of the second direction;

Figure 10 is a schematic diagram of an electromechanical sensor arrangement constituting another embodiment of the invention;

Figure 11 is a schematic diagram of a light curtain arrangement constituting a further embodiment of the invention; and

Figure 12 is a schematic diagram of an electric motor sensor arrangement constituting yet another embodiment of the invention.

[0032] Throughout the following description, identical reference numerals will be used to identify like parts. [0033] Referring to Figure 1 , a footboard 102 of a bed 100 comprises a cavity 104 for storing a lift mechanism 106 therein. The cavity 104 can be accessed through a hinged lid 108. The footboard 102 constitutes a housing for a television 200 (Figure 2) and defines the cavity 104. In this example, the lift mechanism 106 is coupled to and carries a television 200 (Figure 2) is coupled. When in a stowed state, the television 200 is located within the footboard 102. An upper surface 118 (Figure 1 ) of the footboard 102 comprises an opening 202 (Figure 2) therein, the opening 202 being covered by the lid 108 when the lid 108 is in a closed state. When in an open state, the opening 202 provides a port through which the television 200 can pass.

[0034] The lift mechanism 106 is coupled to an electric motor 1 10 by linkage 1 12 comprising, for example a drive shaft. The electric motor 1 10 is coupled to a control unit 1 14 and the control unit 1 14 is coupled to a button or switch 1 16.

[0035] The lift mechanism, the electric and the control unit are part of an obstruction protection apparatus.

[0036] In the stowed state (Figure 1 ), the television 200 is concealed within the footboard 102 of the bed 100, whereas when the television 200 is in a deployed state (Figure 2), a viewable area 204 of the television 200 is located beyond the upper surface 1 18 of the footboard 102.

[0037] Turning to Figure 3, the control unit 1 14 is coupled to a mains electrical power supply 300, for example a mains 240V or 120V AC supply. The controller 1 14 is, as described above, coupled to the electric motor 1 10 and the electric motor 1 10 is coupled to the lift mechanism 106 to drive the lift mechanism 106.

[0038] Referring to Figure 4, in this example, the control unit 1 14 comprises a drive circuit 400 for converting the electric power supplied by the mains electrical power supply 300 to a power supply suitable for driving the electric motor 1 10. The drive circuit 400 can be arranged to convert the electric supply to a suitable DC supply. In this example, the drive circuit 400 is a switched mode power supply that outputs a 12 volt DC power supply to power the electric motor 110 and control logic 402. The drive circuit 400 comprises a first output terminal 406 and a second output terminal 408. [0039] The drive circuit 400 is coupled to control logic 402 in order to power the control logic 402 and to be controlled by the control logic 402, the control logic 402 also being coupled to the switch 1 16 and a current sensor 404. In this example, the current sensor 404 comprises a resistance, for example a very low resistance such as a 0.1 Ohm resistor 410, located in series between the first output terminal 406 of the drive circuit 400 and an input terminal (not shown) of the electric motor 1 10. The resistor 410 is therefore, when in use, located within a current path to be measured. The current sensor 404 also comprises a voltage meter 412 coupled across terminals of the resistor 410, the voltage meter 412 being coupled to the control logic 402 by appropriate interfacing (not shown). The control logic 402 is, in this example, supported by a microcontroller, which comprises an analogue to digital converter (ADC - not shown) in order to convert an analogue output signal generated by the voltage meter 142 to the digital domain. The microcontroller also comprises a memory for recording predetermined threshold values relating to, for example maximum torque values associated with the electric motor 1 10.

[0040] In operation (Figure 5), the control unit 1 14 awaits (Step 500) the button or switch 1 16 to be pressed by a user in order to deploy the television 200 or to stow the television 200 depending upon the current state of the television 200 and, hence, the lift mechanism 106 (stowed or deployed). In this respect, the control logic 402 of the control unit 1 14 records the current positional status of the lift mechanism 106 (a first position) so that the control logic 1 14 can determine (Step 502) the state of the lift mechanism 106. In the event that the lift mechanism 106 is in the stowed state, the control logic 402 instructs (Step 504) the drive circuit 400 to set a drive current for the electric motor 1 10 such that the polarity and magnitude of the drive current results in the electric motor 1 10 causing the lift to translate into the deployed state (a second position).

[0041] During translation, the control logic 402 monitors the output of the current sensor 404 and times translation of the lift mechanism 106. The control logic 402 continually monitors the current being drawn by the electric motor 1 10 in order to determine (Step 506) whether the electric current being drawn exceeds a predetermined threshold value (for example, current) stored by the microcontroller, the value corresponding to a maximum permitted torque. In the event that the current being drawn exceeds or equals the threshold current, the control logic 402 analyses (Step 508) the time elapsed to determine if the draw of addition current occurred after a time corresponding to the lift mechanism 106 reaching the fully deployed state (Figure 6), for example a maximum translation time. If this is the case, the control logic 402 instructs (Step 510) the drive circuit 400 to cut power to the electric motor 1 10 and the control logic 402 continues to await (Step 500) further depression of the button 1 16.

[0042] In the event that the time elapsed is less than an expected deployment time (Figure 7), the reason for the current being equal to or above the threshold current is assumed to be attributable to the lift mechanism 106 experiencing an unexpected physical resistance, for example due to an obstruction impeding or preventing movement of the lift mechanism 106. In this respect, the electric drive current does not conform to a predetermined criterion associated with substantially unfettered translation of the lift mechanism 106. In such circumstances, the control logic 402 instructs (Step 512) the drive circuit 400 to cut the power to the electric motor 1 10 and then, optionally, instructs (Step 514) the drive circuit 400 to reverse the electric motor 1 10 for a predetermined period of time or translation distance of the lift mechanism 106. By reversing the electric motor 1 10, it may be possible to allow the obstruction to be freed from a path of the lift mechanism 106. In this example, a reset procedure then needs to be executed, for example holding the switch 1 16 depressed for a predetermined period of time, such as 5 seconds, before normal operation of the lift mechanism 106 can resume.

[0043] Hence, the control unit 1 14 determines when translation of the lift mechanism 106 has been obstructed by an obstruction and halts operation of the lift mechanism 106 in response to detection of the obstruction.

[0044] The above technique is similarly applied in relation to translating the lift mechanism 106 to a stowed state. In this regard, the control unit 1 14 again awaits (Step 500) the button or switch 1 16 to be pressed by a user in order to deploy the television 200 or to stow the television 200 depending upon the current state of the television 200 and, hence, the lift mechanism 106 (stowed or deployed). In this example, the lift mechanism 106 is now in the deployed state (a first position) and so the control logic 1 14 determines (Step 502) that the lift mechanism 106 is in the deployed state. The control logic 402 therefore then instructs (Step 516) the drive circuit 400 to set a drive current for the electric motor 1 10 such that the polarity and magnitude of the drive current results in the electric motor 1 10 causing the lift to translate into the stowed state (a second position).

[0045] During translation, the control logic 402 again monitors the output of the current sensor 404 and the time the lift mechanism 106 takes to translate. The control logic 402 continually monitors the current being drawn by the electric motor 1 10 in order to determine (Step 518) whether the electric current being drawn exceeds another predetermined threshold value (for example, current) stored by the microcontroller, the value corresponding to a maximum permitted torque. In the event that the current being drawn exceeds or equals the threshold current, the control logic 402 analyses (Step 520) the time elapsed to determine if the draw of addition current occurred after a time corresponding to the lift mechanism 106 reaching the fully stowed state (Figure 8), for example the maximum translation time. If this is the case, the control logic 402 instructs (Step 522) the drive circuit 400 to cut power to the electric motor 1 10 and the control logic 402 continues to await (Step 500) further depression of the button 1 16.

[0046] In the event that the time elapsed is less than an expected deployment time (Figure 9), the reason for the current being equal to or above the threshold current (in magnitude) is assumed to be attributable to the lift mechanism 106 experiencing an unexpected physical resistance, for example due to an obstruction impeding or preventing movement of the lift mechanism 106 for a predetermined period of time or translation distance of the lift mechanism 106. In this scenario, the electric drive current does not conform to a predetermined criterion associated with substantially unfettered translation of the lift mechanism 106. In such circumstances, the control logic 402 instructs (Step 524) the drive circuit 400 to cut the power to the electric motor 1 10 and then, optionally, instructs (Step 526) the drive circuit 400 to reverse the electric motor 1 10. By reversing the electric motor 1 16, it may be possible to allow the obstruction to be freed from the path of the lift mechanism 106. In this example, a reset procedure then needs to be executed, for example holding the switch 1 16 depressed for a predetermined period of time, such as 5 seconds, before normal operation of the lift mechanism 106 can resume.

[0047] In a simpler implementation than described above, elapse of translation time is not monitored and as soon as a sufficiently high resistance to translation is encountered by the electric motor 1 10, the power supplied to the electric motor 1 10 is removed. In such circumstances, the halting of the electric power to the electric motor 1 10 can be necessary due to the lift mechanism 106 having reached a fully deployed state, for example an end position: a fully stowed state or an obstruction having been encountered. Once the electric motor 1 10 has been deprived of electric power, the control logic 402 responds to a subsequent depression of the switch 1 16 by reversing the direction of motion of the electric motor 1 10 so that the lift mechanism 106 translates in an opposite direction to that immediately before the lift mechanism 106 was halted.

[0048] In the above example, the use of the current sensor 404 in conjunction with the control unit 402 constitutes an example of a translation progress detector, which can be operably coupled to the electric motor 1 10 or, in another embodiment, the lift mechanism 106, in order to detect obstruction of the lift mechanism 106.

[0049] Although the above embodiment has been described in the context of use of a current sensor to detect obstruction of the lift mechanism 106, the skilled person should appreciate that other techniques can be employed to detect obstruction of the lift mechanism 106 so that the control logic 402 can instruct the drive circuit 400 to halt supply of electric current to the electric motor 1 10 in the event of an obstruction or overweight event.

[0050] As an example, an electromechanical sensor arrangement 600 (Figure 10), for example a series of switches 602 or other sensor devices, can be deployed and activated in series as the lift mechanism 106 translates to deploy or stow the television 200. This is another example of a translation progress detector, which comprises in this example an array of progress detecting devices. The switches can either be coupled to the lift mechanism 106 or an interior 604 surface of the cavity 104 in which the lift mechanism 106 resides. In this example, the series of switches 602 is arranged linearly. In the case of the switches being coupled to the interior surface 604 of the lift mechanism 106, a complementary actuating protrusion 605 can be attached to or formed on a corresponding part of the footboard 102 that does not carry the switches, for example the lift mechanism 106 or the internal surface 604 of the cavity 104. In this example, the actuating protrusion 605 is coupled to the internal surface 604 of the cavity 104. The control logic 402 is arranged to analyse time intervals between actuations of neighbouring switches 606, for example from actuation of a first switch of the neighbouring switches to actuation of a second switching of the neighbouring switches and halt current supply to the electric motor 1 10 if a predetermined time period or interval is exceeded. For accuracy, the switches can be relatively closely spaces.

[0051] This technique can be used to monitor translation of the lift mechanism 106 to deploy the television 200 and/or to stow the television 200 and an error signal can be generated in response to detection of an obstruction or other source of resistance to the lift mechanism 106. If desired, the electric motor can be halted in response to detection of a so-called "over-weight" event, which will cause the lift mechanism 106 to translate to the stowed state faster than expected. In such circumstances, the time elapsed between translation of neighbouring switches 606 is measured by the control logic 402 and if a predetermined time threshold is exceeded, the electrical power supplied to the electric motor 1 10 is cut, because the faster than expected successive actuating of the switches 606 is indicative of application of an unexpected downward force of the lift mechanism 106.

[0052] As suggested above, other sensor devices can be employed, including magnetic and/or electromagnetic sensors, for example optical sensors. Although, a single series of switches is employed in this example, the skilled person should appreciate that two separate series of sensors can be employed in order to monitor the deployment and stowing of the television 200, respectively.

[0053] In another example, a strain gauge or pressure sensor can be coupled to the controller 114 and the lift mechanism 106 and used by the control logic 402 to determine when the lift mechanism 106 is being impeded or obstructed or forced, for example when translating between deployed and stowed states. This force-related information is then used in a like manner to that described above in order to halt current supply to the electric motor 1 10 if an obstruction is detected, and optionally to reverse the electric motor 1 10. In this example, a predetermined strain value or pressure value is stored by the microcontroller as a threshold value in order to determine when the lift mechanism 106 is being impeded.

[0054] In a further example (Figure 1 1 ), a presence detector device or devices can be employed, for example a so-called "light curtain" (available, for example from SICK AG) or other optoelectronic devices. In this example, the presence detector is formed from pairs of elongate light curtain devices 700 that are arranged to form a substantially rectangular monitored area 700 that extend around the periphery of the opening 202. An unmonitored, smaller, rectangular area 704 is disposed within the substantially rectangular monitored area 702 in order to allow the television 200 to pass therethrough.

[0055] The light curtain devices 700 are coupled to the control unit 1 14 and used to detect the presence of an obstruction. The light curtain is a beam-based device that emits an array of beams, the breach of any of the beams by, for example an object such as one or more fingers, being detectable by the device. In response to one or more beams being detected, the device generates a breach detection signal that can be used, with suitable interfacing, by the control logic 402. In this respect, the control logic 402 uses the breach detection signal to determine when the lift mechanism 402 is being impeded or obstructed, for example when the lift mechanism 106 translates between deployed and stowed states. This information is then used in a like manner to that described above in order to halt current supply to the electric motor 1 10 if an obstruction is detected, and optionally to reverse the electric motor 1 10.

[0056] In yet another example, the translation progress detector comprises a rotation detector, for example a toothed wheel 800 or a patterned wheel, coupled to the electric motor 1 10, and a sensor 802 in order to detect motion of the lift mechanism 106 or a lack of motion of the lift mechanism 106 during a time interval when the lift mechanism 106 should be translated between the deployed and stowed states. In this example, a source of electromagnetic radiation, for example a light source 804, is provided and aimed at the sensor 802, the toothed wheel 800 being located between the sensor 802 and the light source 804, the sensor 802 detects electromagnetic radiation incident thereupon.

[0057] When the toothed wheel 800 rotates, an alternating signal, for example a pulsed signal, is generated by the sensor 802 operating in conjunction with the light source 804, and used by the control unit 1 14 to detect when the lift mechanism 106 is obstructed. In this respect, the frequency of the alternating signal is associated with the speed at which the electric motor 1 10 rotates. Consequently, if the frequency of the alternating signal reduces, this is indicative of the electric motor 1 10 experiencing resistance, and if the frequency of the alternating falls below a predetermined frequency value set sufficiently low then the electric motor 1 10 has slowed to a stop or close to a stop. This information is then used in a like manner to that described above in order to halt current supply to the electric motor 1 10 if an obstruction is detected, and optionally to reverse the electric motor 110.

[0058] In another embodiment, the sensor 802 can be a magnetic sensor and the source of electromagnetic radiation is not required.

[0059] Similarly, the alternating signal can be generated by a changing linear pattern, for example an alternating pattern of black and white blocks, carried in a substantially vertical manner by the lift mechanism 106 or affixed to the internal surface 604 of the cavity 104. Depending upon the location of the linear pattern, a source of electromagnetic radiation and a sensor can be coupled to the lift mechanism 106 or the internal surface 604 so as to face the pattern. Hence, the alternating signal can be generated by the sensor in conjunction with the source of electromagnetic radiation, and used by the control unit 1 14 to detect a reduction in the motion of the electric motor 1 10 when the lift mechanism 106 is obstructed. This information is then used in a like manner to that described above in order to halt current supply to the electric motor 1 10 if an obstruction is detected, and optionally to reverse the electric motor 1 10.

[0060] Although the above example has been described in the context of the deployment or stowing of the television 200, the skilled person should appreciate that the above examples are applicable to other objects, for example a media device, such as another type of display device, a compact disc player, or a docking station for a digital media player.

Claims

1. An obstruction protection apparatus comprising:

a lift mechanism for an item of furniture;

an electrical motor coupled to the lift mechanism for translating the lift mechanism from a first end position to a second end position; and

a control unit; wherein

the control unit is arranged to determine when translation of the lift mechanism is being obstructed by an obstruction, and to halt operation of the lift mechanism in response to detection of the obstruction.

2. An apparatus as claimed in Claim 1 , wherein the control unit comprises a current sensor in order to measure a drive current being drawn by the electric motor.

3. An apparatus as claimed in Claim 1 or Claim 2, wherein the control unit is arranged to use the determined drive current in order to identify an event corresponding to the lift mechanism being obstructed.

4. An apparatus as claimed in Claim 3, wherein the control unit is arranged to determine when the electric drive current does not conform to a predetermined criterion associated with substantially unfettered translation of the lift mechanism.

5. An apparatus as claimed in Claim 4, wherein the predetermined criterion is evaluated with respect to a threshold value corresponding to a predetermined current value.

6. An apparatus as claimed in Claim 1 , wherein the control unit is coupled to a translation progress detector arranged to monitor translation of the lift mechanism and to generate an error signal in response to the lift mechanism being impeded from translating from a first predetermined location to a second predetermined location.

7. An apparatus as claimed in Claim 6, wherein the translation progress detector comprises an array of progress detecting devices.

8. An apparatus as claimed in Claim 7, wherein

the array of progress detecting devices is disposed linearly;

the array of progress detecting devices comprises a pair of neighbouring progress detecting devices; and

impediment of the translation of the lift mechanism is detectable in response to progress of the lift mechanism not being detected within a predetermined time period by a first of the neighbouring progress detecting devices after detection of progress of the lift mechanism by a second of the neighbouring progress detecting devices.

9. An apparatus as claimed in Claim 7 or Claim 8, wherein the array of progress detecting devices is an array of switching devices and/or sensor devices.

10. An apparatus as claimed in Claim 6, wherein the translation progress detector comprises a rotation detector arranged to generate an output signal in response to rotation of the electric motor.

1 1 . An apparatus as claimed in Claim 10, wherein the rotation detector comprises a toothed wheel coupled to the electric motor and a sensor device arranged to respond to rotation of the toothed wheel.

12. An apparatus as claimed in Claim 1 1 , wherein the sensor device is an electromagnetic radiation sensor.

13. An apparatus as claimed in Claim 1 1 , wherein the sensor device is a magnetic sensor.

14. An apparatus as claimed in Claim 1 , wherein the control unit is coupled to a presence detector device arranged to detect a presence of an object within an area being monitored by the presence detector device, and to generate an output signal in response to detection of the object.

15. An apparatus as claimed in Claim 14, wherein the presence detector is arranged to provide an area through which an intended object can translate without detection thereof.

16. An apparatus as claimed in Claim 14 or Claim 15, wherein the presence detector device is a light curtain device.

17. An apparatus as claimed in any one of the preceding claims, wherein the control unit is arranged to translate the lift mechanism in an opposite direction of travel to a direction of travel when the lift mechanism is obstructed, the translation in the opposite direction of travel being initiated following the obstruction being detected.

18. An apparatus as claimed in Claim 17, wherein the translation in the opposite direction of travel is for a predetermined period of time or distance.

19. A footboard for a bed comprising the obstruction protection apparatus as claimed in any one of the preceding claims.

20. A footboard as claimed in Claim 19, further comprising:

a closable aperture arranged to allow a media device to pass when open.

21 . A bed comprising the obstruction protection apparatus as claimed in any one of Claim 1 to 18.

22. An item of furniture comprising:

a housing, the housing having a closable opening for passage of a media device therethrough;

a lift mechanism disposed within the housing for translating the media device; an electrical motor coupled to the lift mechanism for translating the lift mechanism from a first end position to a second end position; and

a control unit; wherein