AU2016201802B2 - Safety interlock - Google Patents

Abstract

A safety interlock 10 for use with a displaceable component 14 which is displaceable relative to at least one further component 18 includes a detector mechanism 24 mountable relative to the displaceable component 14 for detecting the presence of an object located relative to the displaceable component 14 and for outputting a deactivation signal upon detecting the presence of the object. A carrier arrangement 28 carries the detector mechanism 24, the carrier arrangement 28 being configured to cause operation of the detector mechanism 24 if the carrier arrangement encounters an object out of detection range of the detector mechanism 24. A control unit is responsive to the deactivation signal from the detector mechanism 24. The control unit causes displacement of the component 14 to cease upon receipt of the deactivation signal from the detector mechanism 24. Fig. 1 28 /1 10 32 ,S30 224 ---- 18 25 40 42 44 '28 C 26 46 30 24 -------- 32 F&ig2

Description

28 /1

32 ,S30

224 ---- 18 25

40 42 44 '28

C 26

46

30 24 -------- 32

F&ig2

"Safety interlock"

Cross-Reference to Related Applications

[0001] The present application claims priority from Australian Provisional Patent Application No 2015901090 filed on 26 March 2015, the contents of which are incorporated herein by reference in its entirety.

Technical Field

[0002] This disclosure relates, generally, to a safety interlock and, more particularly, to a safety interlock for use with a displaceable component which is displaceable relative to at least one further component. The disclosure has particular, but not necessarily exclusive, application to adjustable furniture having a number of displaceable components.

Background

[0003] With a displaceable component which is displaceable relative to at least one further component upon receipt of an input signal, a danger exists that an object in the path of the displaceable component could be struck or trapped by displacement of the displaceable component, particularly where an operator is un-sighted with regard to a path of the displaceable component.

[0004] In the case of the object being an animate object, particularly a child or an animal, there is the danger of severe injury being caused to the child or animal. Such risk of injury is compounded if, once the displaceable component has come into contact with the child or animal, the displaceable component continues to be displaced to its rest position. There is the additional danger that, even if the child or animal is not struck by the displaceable component, the displaceable component, when in its rest position, closes off a volume resulting in the child or animal being trapped within that volume without a means for escape.

[0005] In the case of the object being an inanimate object, there is the danger of the displaceable component damaging such an object if it strikes the object or traps the object beneath it as it is displaced towards its rest position.

[0006] While the disclosure is applicable to the displacement of any displaceable component relative to another component, the safety interlock has been developed particularly for use with adjustable furniture which has multiple displaceable components mounted on a base, the displaceable components including a seat portion which is displaceable relative to the base, a backrest adjustably arranged relative to the seat portion and/or the base and a footrest adjustably arranged relative to the seat portion and/or the base.

[0007] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application.

Summary

[0008] In a first aspect, there is provided a safety interlock for use with a displaceable component which is displaceable relative to at least one further component, the safety interlock including a detector mechanism mountable relative to the displaceable component for detecting the presence of an object located relative to the displaceable component and for outputting a deactivation signal upon detecting the presence of the object; a carrier arrangement which carries the detector mechanism, the carrier arrangement being configured to cause operation of the detector mechanism if the carrier arrangement encounters an object out of detection range of the detector mechanism; and a control unit responsive to the deactivation signal from the detector mechanism, the control unit causing displacement of the component to cease upon receipt of the deactivation signal from the detector mechanism, in which the displaceable component is displaceable between a first, home position and a second, extended position, the control unit being responsive to the deactivation signal from the detector mechanism to move the displaceable component to its extended position irrespective of a direction in which the displaceable component was being displaced prior to receipt of the deactivation signal.

[0009] The term "object" is to be understood in a broad sense to include, unless the context clearly indicates otherwise, an animate object, such as an animal or human, or an inanimate object. Further, the term "out of detection range" is to be understood to mean a region immediately below at least one component of the detector mechanism.

[0010] The detector mechanism may comprise a transmitter which transmits a detection signal and a receiver responsive to the detection signal, the transmitter and the receiver being spaced from each other, in use, on opposed sides of a volume to be monitored, the displaceable component being displaceable relative to that volume.

[0011] The detector mechanism maybe operable to output the deactivation signal to the control unit when the receiver fails to receive the detection signal from the transmitter. In other words, the detection signal may be in the form of a beam output by the transmitter and, if the beam is broken, the detector mechanism is operable to output the deactivation signal. The transmitter may be an infrared (IR) transmitter with the receiver being a complementary IR receiver.

[0012] The carrier arrangement may comprise a plurality of carrier elements with a carrier element associated with each of the transmitter and the receiver, the carrier elements being arranged on the opposed sides of the volume, at least one of the carrier elements carrying one of the transmitter and the receiver.

[0013] The displaceable component maybe mounted relative to the at least one further component via at least one compound linkage arm with the at least one of the carrier elements being displaceably mounted relative to the at least one compound linkage arm. By "compound linkage" is meant that the arm comprises a plurality of interconnected, articulated links for enabling the displaceable component to be displaced relative to the at least one further component.

[0014] The at least one of the carrier elements maybe pivotally mounted on the arm, the at least one of the carrier elements being displaceable from a rest position to an activation position when the at least one of the carrier elements comes into contact with the object. When the at least one of the carrier elements is in its activation position, the transmitter or receiver carried by that carrier element may rely on interaction with the at least one compound linkage arm of the displaceable component to cause the detector mechanism to generate the deactivation signal.

[0015] Further, when the at least one of the carrier elements is displaced from its rest position into its activation position, interference from the compound linkage arm of the displaceable component may cause a break in the detection signal between the transmitter and the receiver to cause generation of the deactivation signal.

[0016] The carrier arrangement may include an urging device, interconnected between the arm and its associated at least one of the carrier elements for urging that carrier element into its rest position, the at least one of the carrier elements acting against the urging device when being displaced from the rest position to the activation position.

[0017] The at least one of the carrier elements may carry one of the transmitter and the receiver with the other of the carrier elements carrying the other of the transmitter and receiver.

[0018] The displaceable component maybe mounted relative to the at least one further component by a pair of spaced compound linkage arms, each of the arms carrying one of the carrier elements and each carrier element being displaceably arranged on its associated arm.

[0019] The control unit maybe configured to move the displaceable component to its extended position, on receipt of the deactivation signal, irrespective of an input of an operator.

[0020] In a second aspect, there is provided an article of furniture which includes a base; at least one displaceable component displaceably carried relative to the base; and a safety interlock, as defined in paragraph [0008] above, optionally further including any of the integers defined in any of paragraphs [0010] to [0019] above, the detector mechanism of the safety interlock being mounted relative to the displaceable component of the article of furniture for detecting the presence of an object located relative to the displaceable component of the article of furniture and for outputting the deactivation signal upon detecting the presence of that object.

[0021] The article of furniture may include a seat portion displaceably arranged relative to the base and the at least one displaceable component may be a footrest displaceably carried by one of the seat portion and the base. Further, the article of furniture may include a backrest which is also displaceable relative to the base, the backrest moving in unison with the seat portion and footrest when the latter two are displaced relative to the base.

[0022] The article of furniture may include user-operated controls for effecting displacement of the at least one displaceable component relative to the base, the control unit of the safety interlock being responsive to user inputs via the user-operated controls. The user-operated controls may be gesture-responsive controls. More particularly, the user-operated controls may be responsive to gestures such as swiping to effect displacement of the displaceable component relative to the base. It will be appreciated that the gestures may not involve the user actually touching the controls but, instead, the controls may include proximity sensors for sensing motion, for example, of the user's hand or fingers past the user-operated controls.

Brief Description of Drawings

[0023] An embodiment of the disclosure is now described by way of example with reference to the accompanying drawings in which:

[0024] Fig. 1 shows a perspective view of an embodiment of a safety interlock, in use;

[0025] Fig. 2 shows a perspective view of a carrier element of a carrier arrangement of the safety interlock;

[0026] Fig. 3 shows a side view of a part of an article of furniture carrying the safety interlock;

[0027] Fig. 4 shows a side view of the article of furniture in a retracted, home configuration; and

[0028] Fig. 5 shows a side view of the article of furniture in an extended configuration illustrating the safety interlock.

Detailed Description of Exemplary Embodiments

[0029] In Fig. 1 of the drawings, reference numeral 10 generally designates an embodiment of a safety interlock for use with a displaceable component which is displaceable relative to at least one further component.

[0030] For ease of reference, the disclosure will be described with reference to its application to an article of furniture in the form of a seat 12 (Figs. 4 and 5). The seat 12 is either a stand alone seat such as an armchair or it may form a component of a sofa. The displaceable component is a footrest 14 which extends and retracts relative to a seat portion 16 mounted displaceably on a base 18. The seat 12 further includes a backrest 20 and a headrest 22 which are also displaceably arranged on the base 18.

[0031] It will be appreciated that the safety interlock 10 is able to be used for monitoring and controlling displacement of any other displaceable component of the adjustable furniture. Still further, it will be appreciated that the article of furniture could be something other than a seat. For example, the article of furniture could be a sofa or a bed having a storage compartment closed off by a mattress carrying portion, etc.

[0032] In addition, it will further be appreciated that the safety interlock 10 could be used in applications other than furniture, for example, a pivoting garage door having a compound linkage for controlling opening and closing of the garage door or any other closure member or displaceable member having such a compound linkage.

[0033] The safety interlock 10 includes a detector mechanism 24. The detector mechanism 24 is mounted to the footrest 14 of the seat 12 and monitors a volume 25 beneath the footrest 14. The footrest 14 is connected to the seat portion 16 by a pair of laterally spaced, compound linkage arms 26. The detector mechanism 24 is mounted to the arms 26 to be displaced together with the arms 26 as the footrest 14 is displaced relative to the seat portion 16.

[0034] The detector mechanism 24 is carried on a carrier arrangement 28. The carrier arrangement 28 comprises a pair of carrier elements, each in the form of a carrier plate 30 laterally spaced relative to the volume 25. Each carrier plate 30 carries a component of the detector mechanism 24.

[0035] In this embodiment, the detector mechanism 24 comprises an infrared (IR) transmitter 32 carried by one of the carrier plates 30 and a complementary IR receiver 34 carried by the other of the carrier plates 30. The transmitter 32 transmits a detection signal, in the form of an IR beam, to be detected by the receiver 34. Provided the IR beam between the transmitter 32 and the receiver 34 remains unbroken, the footrest 14 is able to be displaced relative to the seat portion 16. As soon as the IR beam is broken by an obstruction in the volume 25, for example, when an object in the volume 25 causes a break in transmission of the signal from the transmitter 32 to the receiver 34, the detector mechanism 24 generates a deactivation signal. The deactivation signal causes displacement of the footrest 14 of the seat 12 to cease immediately.

[0036] The safety interlock 10 includes a control unit 36 (Fig. 5) mounted on the base 18 of the seat 12. In normal operation of the seat 12, the control unit 36 is operable to control displacement of the components of the seat 12, such as the footrest 14, the seat portion 16, the backrest 20 and the headrest 22 relative to the base 18 on receipt of control signals from user operated controls 38 mounted on the seat portion 16 of the seat 12. The control unit 36 is, however, also responsive to the deactivation signal output by the detector mechanism 24.

[0037] More particularly, as described above, upon receipt of the deactivation signal by the control unit 36, the control unit 36 is configured to cease displacement of the footrest 14 immediately. Moreover, the control unit 36 is operable, upon receipt of the deactivation signal from the detector mechanism 24, to cause the footrest 14 to move to an extended position, as shown, for example, in Fig. 5 of the drawings, relative to the base 18 irrespective of the control signals that may have been received via the user-operated controls 38.

[0038] Each carrier plate 30 is displaceably mounted on its associated arm 26 of the footrest 14. More particularly, each carrier plate 30 is pivotally mounted on its associated arm 26 and is pivotally displaceable from a rest position, as shown in Fig. 3 of the drawings, to an activation position (not shown). When the carrier plates 30 are in their rest position, the transmitter 32 and the receiver 34 are in line of sight of each other enabling the receiver 34 to receive the detection beam from the transmitter 32.

[0039] The safety interlock 10 includes an urging device, in the form of a coil spring 40, interposed between each carrier plate 30 and its associated arm 26. The coil spring 40 includes engaging formations 42 and 44 for engaging the arm 26 and the carrier plate 30, respectively, for urging the carrier plate 30 into its rest position. The coil spring 40 is carried on a stub axle 46 which defines a pivot axis for the carrier plate 30.

[0040] In use, the seat 12 is electrically operable to be able to be extended or reclined or reversed into a retracted or upright configuration as shown in Fig. 4 of the drawings. As described above, the seat 12 is operated by the user operated controls 38 to effect extension of the seat 12 from the position shown in Fig. 4 of the drawings to a position, for example, as shown in Fig. 5 of the drawings where at least the footrest 14 is extended relative to the seat portion 16 and the seat portion 16, in turn, is displaced relative to the base 18 of the seat 12.

[0041] The user operated controls 38 comprise two sets of buttons 48 and 50. The buttons 48 are used to extend and retract the seat portion 16 relative to the backrest 20 while the buttons 50 are used to extend and retract the footrest 14 relative to the seat portion 16. The buttons 48 and are touch control buttons but are also gesture responsive. In other words, the buttons 48 and have proximity detection capabilities so that, by appropriate gestures by the user, the components of the seat 12 can be extended or retracted, as the case may be.

[0042] For example, by a user waving his or her hand or fingers 52 past the buttons, as shown schematically in Fig. 5 of the drawings, in the direction of arrow 54, the footrest 14 is extended relative to the seat portion 16 and/or the seat portion 16 is extended relative to the backrest 20. Conversely, if the user waves his or her hand/fingers 52 past the buttons 48 and 50 in the direction of arrow 56, the footrest 14 is retracted relative to the seat portion 16 to the position shown in Fig. 4 of the drawings and/or the seat portion 16 is retracted relative to the backrest 20 to the position shown in Fig. 4 of the drawings.

[0043] The control unit 36 also includes a memory function whereby a user is able to insert his or her preferred settings for the seat 12. By appropriate gestures, for example, the user waving his or her hand/fingers 52 past the controls 38 a predetermined number of times, the seat 12 is placed in the preferred settings for that user. The user is also able to reverse the operation of the seat 12 to its upright or retracted position to enable the user more easily to get off the seat 12 by appropriate manipulation of the controls 38.

[0044] A danger exists that, when the footrest 14 is in the extended position, as shown in Fig. 5 of the drawings, a child or animal could, unbeknown to an occupier of the seat 12, enter the volume 25 beneath the footrest 14 or some other inanimate object could enter the volume 25.

[0045] When the user wishes to alight from the seat 12 and operates the controls 38 to cause the seat 12 to revert to its retracted position, the volume 25 is out of the sight of the user. An object, be it an animate object or an inanimate object, could be struck by the footrest 14 causing injury, in the case of an animate object, or damage to an inanimate object. Further, in the case of the object being a child or animal, there is the additional danger, even if the child or animal is not injured, of the child or animal being trapped within the volume 25 under the seat 12 with no means for escape.

[0046] The provision of the detector mechanism 24, to a large extent, solves this problem in that, if the object is detected by the detector mechanism 24, by the IR beam being broken due to the presence of the object, a deactivation signal is sent by the detector mechanism 24 to the control unit 36. The control unit 36 immediately causes retraction of the footrest 14 to cease and, further, reverses the motion of the footrest 14 so that it reverts to its extended position as shown in Fig. 4 of the drawings.

[0047] If the object is directly below one of the arms 26 of the footrest 14, the detector mechanism 24 may not detect the presence of the object until the object has already been struck by the arm 26 of the footrest 14.

[0048] By mounting the transmitter 32 and the receiver 34 of the detector mechanism 24 on the carrier plates 30, this problem is, to a large extent, obviated. It is to be noted that each carrier plate 30 is shaped so that it extends operatively below its associated arm 26 of the footrest 14. Hence, if the object is located directly beneath the arm 26, as the footrest 14 is displaced towards its retracted position, the carrier plate 30 comes into contact with the object before the arm 26. The carrier plate 30, upon coming into contact with the object, pivots in the direction of arrow 58 (Fig. 3) about the pivot axis of the stub axle 46.

[0049] As the carrier plate 30 pivots away from its rest position, the transmitter 32 or receiver 34, as the case may be, moves into alignment with the arm 26 breaking transmission of the IR beam between the transmitter 32 and receiver 34. When this occurs, the detector mechanism 24 generates the deactivation signal and sends it to the control unit 36 causing the control unit 36 immediately to cease retraction of the footrest 14 and reversing the retraction of the footrest 14 so that the footrest 14 again adopts its extended position as shown in Fig. 5 of the drawings.

[0050] Once the danger has passed, i.e. the object has been removed from below the carrier plate 30, the spring 40 urges the carrier plate 30 back to its rest position so that the transmitter 32 and the receiver 34 are, once again, in line of sight of each other.

[0051] It is therefore an advantage of the described safety interlock 10 that an interlock 10 is provided which is safer and further reduces the likelihood of injury to children or animals present in the path of a displaceable component or damage to an object present in the path of the displaceable component. The safety interlock 10 is able to be easily retro-fitted to existing displaceable components and is easy to install in the case of new equipment.

[0052] The safety of the equipment is further enhanced in that the control unit 36 is responsive to receipt of a deactivation signal to reverse movement of the displaceable component to a position where the child or animal will not be injured or trapped and/or an object will not be damaged.

[0053] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (17)

CLAIMS:

1. A safety interlock for use with a displaceable component which is displaceable relative to at least one further component, the safety interlock including a detector mechanism mountable relative to the displaceable component for detecting the presence of an object located relative to the displaceable component and for outputting a deactivation signal upon detecting the presence of the object; a carrier arrangement which carries the detector mechanism, the carrier arrangement being configured to cause operation of the detector mechanism if the carrier arrangement encounters an object out of detection range of the detector mechanism; and a control unit responsive to the deactivation signal from the detector mechanism, the control unit causing displacement of the component to cease upon receipt of the deactivation signal from the detector mechanism, in which the displaceable component is displaceable between a first, home position and a second, extended position, the control unit being responsive to the deactivation signal from the detector mechanism to move the displaceable component to its extended position irrespective of a direction in which the displaceable component was being displaced prior to receipt of the deactivation signal.

2. The safety interlock of claim 1 in which the detector mechanism comprises a transmitter which transmits a detection signal and a receiver responsive to the detection signal, the transmitter and the receiver being spaced from each other, in use, on opposed sides of a volume to be monitored, the displaceable component being displaceable relative to that volume.

3. The safety interlock of claim 2 in which the detector mechanism is operable to output the deactivation signal to the control unit when the receiver fails to receive the detection signal from the transmitter.

4. The safety interlock of claim 2 or claim 3 in which the carrier arrangement comprises a plurality of carrier elements with a carrier element associated with each of the transmitter and the receiver, the carrier elements being arranged on the opposed sides of the volume, at least one of the carrier elements carrying one of the transmitter and the receiver.

5. The safety interlock of claim 4 in which the displaceable component is mounted relative to the at least one further component via at least one compound linkage arm with the at least one of the carrier elements being displaceably mounted relative to the at least one compound linkage arm.

6. The safety interlock of claim 5 in which the at least one of the carrier elements is pivotally mounted on the arm, the at least one of the carrier elements being displaceable from a rest position to an activation position when the at least one of the carrier elements comes into contact with the object.

7. The safety interlock of claim 6 in which, when the at least one of the carrier elements is in its activation position, the transmitter or receiver carried by the carrier element relies on interaction with the at least one compound linkage arm of the displaceable component to cause the detector mechanism to generate the deactivation signal.

8. The safety interlock of claim 7 in which, when the at least one of the carrier elements is displaced from its rest position into its activation position, interference from the compound linkage arm of the displaceable component causes a break in the detection signal between the transmitter and the receiver to cause generation of the deactivation signal.

9. The safety interlock of any one of claims 6 to 8 in which the carrier arrangement includes an urging device, interconnected between the arm and its associated at least one of the carrier elements for urging that carrier element into its rest position, the at least one of the carrier elements acting against the urging device when being displaced from the rest position to the activation position.

10. The safety interlock of any one of claims 5 to 9 in which the at least one of the carrier elements carries one of the transmitter and the receiver with the other of the carrier elements carrying the other of the transmitter and receiver.

11. The safety interlock of claim 10 in which the displaceable component is mounted relative to the at least one further component by a pair of spaced compound linkage arms, each of the arms carrying one of the carrier elements and each carrier element being displaceably arranged on its associated arm.

12. The safety interlock of any one of the preceding claims in which the control unit is configured to move the displaceable component to its extended position, on receipt of the deactivation signal, irrespective of an input of an operator.

13. An article of furniture which includes a base; at least one displaceable component displaceably carried relative to the base; and a safety interlock, as claimed in any one of the preceding claims, the detector mechanism of the safety interlock being mounted relative to the displaceable component of the article of furniture for detecting the presence of an object located relative to the displaceable component of the article of furniture and for outputting the deactivation signal upon detecting the presence of that object.

14. The article of furniture of claim 13 which includes a seat portion displaceably arranged relative to the base and in which the at least one displaceable component of the article of furniture includes a footrest displaceably carried by one of the seat portion and the base.

15. The article of furniture of claim 14 which includes a backrest which is also displaceable relative to the base.

16. The article of furniture of any one of claims 13 to 15 which includes user-operated controls for effecting displacement of the at least one displaceable component relative to the base, the control unit of the safety interlock being responsive to user inputs via the user-operated controls.

17. The article of furniture of claim 16 in which the user-operated controls are gesture responsive controls.