WO2005075786A1

WO2005075786A1 - Device for limiting closure of a gap

Info

Publication number: WO2005075786A1
Application number: PCT/AU2005/000144
Authority: WO
Inventors: Neil Francis De La Coeur; Paul Anthony Mizzi
Original assignee: Neil Francis De La Coeur; Paul Anthony Mizzi
Priority date: 2004-02-04
Filing date: 2005-02-04
Publication date: 2005-08-18

Abstract

A device (10) for limiting closure of a gap (16) between two relatively movable members (12,14) when an obstruction (70) protrudes into the gap (16). The device (10) including a first component (18) adapted to be associated with a first (12) of the two relatively movable members (12,14) and a second component (20) adapted to be associated with the other (14) of the two relatively movable members (12,14) and to be pivotably movable relative to the first component (18). The device (10) further includes at least one sensor (64,66) to detect the obstruction (70) in the gap (16) and means (36,38,40,42,44,50,52,54,56) adapted to be operable when the at least one sensor (64,66) detects the obstruction (70) to restrict the relative movement between the first and second components (18,20) to limit closure of the gap (16) between the two relatively movable members (12,14).

Description

DENICE FOR LIMITING CLOSURE OF A GAP

FIELD OF THE INVENTION This invention relates to a device for limiting closure of a gap and relates particularly, though not exclusively, to a safety device for preventing the crushing of fingers from closing doors or windows.

BACKGROUND OF THE INVENTION Safety devices for preventing injuries related to door jambs are well known. US Patent No. 4,290,233 by Kawneer Company, Inc. (the 'Kawneer' patent), discloses a safety door entrance device which includes a door mounted for swinging movement on hinges connected to a door jamb and a protector for continuously bridging a gap formed between the door heel and adjacent jamb as the door swings open and closed. This protector prevents a person's fingers or toes or other objects from being accidentally inserted in the gap and being subject to damage when the door swings closed. US Patent No. 5,359,812 by Charles D. Mayfield (the 'Mayfield* patent), discloses a safety device which is described as a slidable door guard for temporarily bridging or covering the opening formed between the door heel and an adjacent door jamb. This device essentially consists of a first engaging or male member and a second receiving or female member, the female member having a pocket therein to slidingly hold at least a portion of the male member therein as the door is opened and/or closed, to prevent children, or any person for that matter, from accidentally crushing their fingers as the door is closed. US Patent No. 5,509,235 by Radhakrishnan Chander (the 'Chander' patent), discloses a safety device for hinged doors, which includes a spring- loaded wedge-shaped stopper means, connected to a bracket that is attached to a door or door jamb near its hinged side. When the spring is not loaded, the stopper means is positioned in an obtrusive manner in the front face gap near the hinge side created by the opening and closing of the hinged door, thereby preventing a partially opened door from being shut, in particular by small children who can accidentally insert their fingers or other body parts into the gap. At any stage that an adult so desires to close the door they can do so by rotating the stopper means, about its hinge pin connecting it to the bracket, against the restoring spring, away from the gap, which provides for normal closure of the door. US Patent No. 5,581,844 by Robert Raheb (the Raheb' patent), discloses a safety device which is essentially a modified door hinge that has provision for the securing of a removable block member against a leaf of the hinge on a door jamb. When in place, this block member prevents the door from completely closing, therefore preventing fingers or other body parts from getting caught and damaged between an edge of the door and the door jamb. This block member continues to prevent the door from closing until such time as it is removed and, as such, will not prevent the door from closing again until it is placed back into position. In each of the patents described above the safety devices disclosed are effective in reducing the chance of an injury associated with jambs of doors. However each device has its own drawbacks. In the case of the Kawneer and Mayfield patents, these safety devices are protective guards which need to be permanently in place if they are to protect a person, in particular a child, from jamming their fingers. These devices restrict access to hinges requiring attention and restrict door movement due to added friction or wear on the sliding guard. The Chander and Raheb patents describe devices which manually need to be placed into position and permanently restrict the door from closing. These devices are frustrating as an adult must remove or re- position the stopper means before the door can be closed. The Chander and Raheb devices will not prevent an accidental injury if they are not in place. If an adult forgets to put the device in place an injury to a child can occur. An object of the present invention is to provide an improved device and/or method for preventing jamming and/or injury of fingers, toes or other obj ects between doors/windows and j ambs. A further object of the present invention is to provide a device and/or method which allows a door or window to open and close in a normal manner, whilst there is no obstruction in the closing gap formed between the adjacent surfaces of the door or window and the jamb.

SUMMARY OF THE INVENTION According to the present invention there is provided a device for limiting closure of a gap between two relatively movable members when an obstruction protrudes into said gap, said device including: a first component adapted to be associated with a first of said two relatively movable members; a second component adapted to be associated with the other of said two relatively movable members and to be pivotably movable relative to said first component; at least one sensor to detect said obstruction in said gap; and means adapted to be operable when said at least one sensor detects said obstruction to restrict said relative movement between said first and second components to limit closure of said gap between said two relatively movable members. Preferably said means adapted to be operable includes a mechanism associated with at least one of said first or second components, said mechanism being adapted to be operable in order to restrict said pivotable movement between said first and second components about their pivot. Preferably said pivotable movement between said first and second components is effected in association with at least one shaft and preferably said mechanism includes at least one first wedge component associated with and influenced by said at least one shaft and at least one further wedge component operable to be independent of said at least one shaft and adapted to be capable of wedging said at least one first component associated with said at least one shaft in order to restrict said pivotable movement between said first and second components. It is further preferred that said at least one first wedge component and said at least one further wedge component have substantially matched crescent- shaped mating surfaces. Preferably said at least one first wedge component is internally threaded and is influenced by a worm gear formed on said at least one shaft. It is further preferred that said at least one first wedge component is adapted to be movable up and down said wonn gear formed on said at least one shaft but is restricted from rotating relative to said at least one shaft by a groove formed on said at least one first wedge component that receives a rail formed on one of said first or second components of said device. Preferably said at least one first wedge component contacts said at least one further wedge component when substantially no gap exists between said two relatively movable members, such that substantially no void exists between said mating surfaces of said at least one first and said at least one further wedge components. Preferably said at least one first wedge component moves down said worm gear formed on said at least one shaft when said two relatively movable members are moved to create said gap. Preferably said mating surfaces of said at least one first wedge component and said at least one further wedge component remain in partial contact with one another even when said gap exists between said two relatively movable members. Preferably said at least one first wedge component moves up said worm gear formed on said at least one shaft when said two relatively movable members are moved so that substantially no gap exists between said two relatively movable members. It is further preferred that said at least one further wedge component is adapted to be movable with said at least one shaft until said obstruction is detected in said gap, and wherein upon detecting said obstruction in said gap said at least one further wedge component of said device is adapted to be independent of said at least one shaft. Preferably, when said at least one further wedge component is adapted to be independent of said at least one shaft, said at least one further wedge component restricts movement of said at least one first wedge component moving upward with said at least one shaft by acting against said at least one first wedge component and restricting any further upward movement, and wherein said restricted upward movement of said at least one first wedge component restricts said pivotable movement between said first and second components of said device about said at least one shaft, which in turn restricts said relative movement between said two relatively movable members. Preferably said at least one further wedge component is adapted to be independent of said at least one shaft in association with at least one key. Preferably said at least one key is operable in association with at least one solenoid and/or at least one resiliently biased means. In a practical preferred embodiment said at least one sensor is a heat or motion detector such as a passive infrared (PIR) device, an active motion sensor such as a light, microwave or sound emitting device, or any suitable combination thereof. It is also preferred that said device is powered by a battery means or may be hard- wired and powered by a mains supply. In a further practical preferred embodiment said at least one sensor is a photosensor, and wherein said device further includes a reflector means, positioned at any suitable location, whereby said photosensor senses an obstruction if its emitted beam between said photosensor and said reflector means is breached. In a preferred embodiment said device may include control means to automatically resume normal non-restricted movement between said first and second component after said obstruction has been cleared or, alternatively, said device may include a reset means to reset said mechanism after said obstruction has been cleared in order to resume normal non-restricted operation of said device and to allow non-limited movement between said two relatively movable members. In a practical embodiment one of said two relatively movable members is a door or window and the other of said two relatively movable members is a door or window jamb. In a further practical embodiment said device is a hinge, wherein said first and second components are first and second hinge leaves respectively. Preferably each of said first and second hinge leaves includes at least one cooperating knuckle, formed along a common edge, to allow for said pivotable movement between said first and second hinge leaves in association with said at least one shaft. Preferably said mechanism of said hinge is associated with at least one of said knuckles of said first or second hinge leaves and adapted to be able to restrict said pivotable movement between said first and second hinge leaves relative to said at least one shaft. In a preferred embodiment of said hinge said mechanism is housed within said at least one knuckle of said first or second hinge leaves, said mechanism of said hinge being capable of restricting said pivotable movement between said first and second hinge leaves by restricting the rotational movement of said at least one shaft relative to said knuckle housing said mechanism. It is also preferred that said at least one sensor and any other required components of said hinge are housed within the same or any other of said at least one knuckles of said first or second hinge leaves, so that said hinge may substantially resemble a conventional hinge. According to a further aspect of the present invention there is provided a method for limiting closure of a gap between two relatively movable members when an obstruction protrudes into said gap, said two relatively movable members being movable in association with a first component adapted to be associated with a first of said two relatively movable members and a second component adapted to be associated with the other of said two relatively movable members and to be pivotably movable relative to said first component, said method including the steps of: monitoring said gap for said obstruction in said gap by said at least one sensor; and restricting said pivotable movement between said first and second components relative to their pivot when said at least one sensor detects said obstruction to limit closure of said gap between said two relatively movable members. In a preferred embodiment said two relatively movable members resume non-restricted operation automatically upon said obstruction being withdrawn from said gap. In an alternative preferred embodiment said two relatively movable members resume non-restricted operation upon manually operating a reset mechanism. It is preferred that said first and second components are adapted to be pivotably movable in association with at least one shaft. Preferably said pivotable movement between said first and second components is restricted in association with at least two wedge components which restrict said pivotable movement between said first and second components by preventing relative movement about their pivot relative to said at least one shaft. In a practical preferred embodiment said at least two wedge components have substantially matched crescent-shaped mating surfaces. Preferably a first of said at least two wedge components is adapted to move up and down said at least one shaft in association with at least one worm gear, wherein a second of said at least two wedge components is adapted to rotate with said at least one shaft until said obstruction is detected in said gap, at which time said second wedge component is independent of said at least one shaft, and wherein when said second wedge component is independent of said at least one shaft said second wedge component restricts upward movement of said first wedge component which restricts said pivotable movement between said first and second components. In a preferred embodiment said at least two wedge components are operable in association with at least one key, at least one solenoid and/or at least one resiliently biased means. In yet a further preferred embodiment said at least one sensor is a heat or motion detector such as a passive infrared (PIR) device, an active motion sensor such as a light, microwave or sound emitting device, or any suitable combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred constructions of a device for limiting closure of a gap in accordance with the invention. The ensuing description is given by way of non-limitative examples only and is with reference to the accompanying drawings, wherein: Fig. 1 is a perspective view of a door and door jamb fitted with a device made in accordance with a first preferred embodiment of the invention; Fig. 2 is a cross-sectional plan view of the door and door jamb of Fig. 1, shown with the door in a closed position; Fig. 3 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 3-3 of Fig. 2; Fig. 4 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 4-4 of Fig. 3; Fig. 5 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 5-5 of Fig. 3; Fig. 6 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 6-6 of Fig. 3; Fig. 7 is a cross-sectional plan view of the door and door jamb of Fig. 1, shown with the door in a open position; Fig. 8 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 8-8 of Fig. 7; Fig. 9 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 9-9 of Fig. 8; Fig. 10 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 10- 10 of Fig. 8; Fig. 11 is a cross-sectional view of the device of Fig. 1, taken along and in the direction of arrows 11-11 of Fig. 8; Fig. 12 is a similar view to that of Fig. 10, showing a finger obstructing the sensor of the device of Fig. 1 in the gap formed between the door and the door jamb; Figs. 13a & 13b are partial enlarged cross-sectional views of the device of Fig. 1, showing the device in an activated state after the finger of Fig. 12 has obstructed the gap formed between the door and the door jamb; Figs. 14a & 14b are partial enlarged cross-sectional views of a device made in accordance with a second preferred embodiment of the invention which is also suitable to be fitted to the door and door jamb of Fig. 1, shown in a pre-activated and an activated state, respectively; and Fig. 15 is an enlarged view of two internal components of the device of Fig. 1, shown separate from the device for illustrative purposes only. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In Fig. 1 there is shown a door 12 mounted for swinging movement on a door jamb 14 using at least one conventional hinge (not shown) and a device 10 for limiting closure of any gap 16 formed between adjacent surfaces of door 12 and door jamb 14, when door 12 is opened. Device 10 includes a pair of rectangular flat-faced mounting plates 18,20 each for fastening to a respective surface of door 12 and/or door jamb 14 via screws or the like (not shown). One edge of mounting plate 18 is formed with first and second tubular guideways 22 and 24, respectively, in linear, coaxial alignment and with a space for positioning of a third tubular guideway 26 pertaining to mounting plate 20. Guideways 24 & 26 together form a longitudinally aligned tube for reception of a shaft 28, whilst guideways 22 & 26 together form a longitudinally aligned tube for reception of a bearing 30. The combination of guideways 22,24,26, shaft 28 and bearing 30 facilitates pivotable movement between mounting plates 18,20. As shown in Figs. 3 and 8, bearing 30 is positioned between and cooperates with the concealed mating ends of guideways 22,26 such that guideways 22,26 are pivotably movable with respect to one another relative to bearing 30. Shaft 28 is integral with and projects from the concealed end of guideway 24 and extends into an opening formed in the mating concealed end of guideway 26 to facilitate pivotable movement between guideways 24,26. As best seen in Figs. 13a and 13b, near the end of shaft 28 and within guideway 26 there is formed a groove 32 which cooperates with a support 34 formed within guideway 26. Support 34 sits within groove 32 of shaft 28 and supports the relative movement between guideways 24,26 about shaft 28. Housed within guideway 26 is a rotating wedge element 36 and a cooperating nut 38. Both rotating wedge element 36 and nut 38 are preferably constructed of the same material and have matched crescent-shaped cooperating surfaces, as seen in Fig. 15, but may have any other suitably shaped surface or dimension, or may be constructed out of materials having different properties such as, for example, knurled surfaces or one hard and one softer material, in order to achieve the same result. Nut 38 is internally threaded and is adapted to move longitudinally up and down shaft 28 along a worm gear 40 (Figs. 3 and 8) formed on shaft 28 when guideways 22,24,26 rotate relative to one another as a result of opening and closing of door 12. Arranged on an internal surface of guideway 26 is a rail 42 which is received within a slot 44 formed on nut 38. Nut 38 may move up and down worm gear 40 of shaft 28 but may not rotate within and relative to guideway 26 due to rail 42 and slot 44. As a result of the arrangement of rail 42 and slot 44 the cooperating surface of nut 38, the surface that faces rotating wedge element 36, always remains uniform. Rotating wedge element 36 is rotatable relative to shaft 28 and is positioned between nut 38 and abuts against a thrust block 46 formed internally and integral with guideway 26. Arranged on the surface of rotating wedge element 36 facing thrust block 46 is a key receiving slot 48 for receiving a retractable key 50. In the non-obstructed mode of operation of device 10 (Figs. 3 to 11), key 50 is normally engaged with rotating wedge element 36 within key receiving slot 48. As a result of key 50 being engaged within key receiving slot 48, rotating wedge element 36 normally rotates with shaft 28 as a result of the same being caused to rotate as door 12 is opened and closed. The design of rotating wedge element 36 and normally engaged key 50 is such that rotating wedge element 36 always remains abutted against thrust block 46, even when rotating with shaft 28. As rotating wedge element 36 normally rotates with shaft 28 the cooperating surface of rotating wedge element 36, the surface that faces nut 38, shifts (for example, approximately 90°) with the rotation of shaft 28 relative to the uniform surface of nut 38. When door 12 is closed, as seen in Figs. 2 to 6, the cooperating surfaces of rotating wedge element 36 and nut 38 of device 10 mate with one another such that there exists substantially no void between respective surfaces of rotating wedge element 36 and nut 38. In the closed position of door 12, nut 38 abuts against rotating wedge element 36, which in turn abuts against thrust block 46, and nut 38 is as far upward of shaft 28 towards thrust block 46, as is possible due to the conformity of the cooperating crescent-shaped mated surfaces of nut 38 and rotating wedge element 36. When door 12 is open, as seen in Figs. 7 to 11, rotating wedge element 36 has moved with shaft 28 (i.e. approximately 90°) whilst still remaining in contact with thrust block 46, and nut 38 has moved down worm gear 40 due to the rotation of shaft 28 caused by door 12 being open. Due to the crescent- shaped surfaces of rotating wedge element 36 and nut 38, a portion of each of the surfaces of rotating wedge element 36 and nut 38 always remains in contact (best seen in Figs. 8 and 13b), even when nut 38 has moved downwards relative to shaft 28. Thus when door 12 is open (Figs. 7 to 11) the cooperating surface of rotating wedge element 36 has shifted relative to the uniform surface of nut 38, whilst a portion of each of rotating wedge element 36 and nut 38 still remains in contact and rotating wedge element 36 still abuts against thrust block 46. This constant contact between respective surfaces of rotating wedge element 36 and nut 38, in combination with thrust block 46, restricts upward movement of nut 38 along worm gear 40 of shaft 28 when key 50 is retracted and disengaged from the rotating wedge element 36. That is, nut 38 can no longer move upward relative to shaft 28 if key 50 is retracted (Figs. 13a and 13b) as rotating wedge element 36 will not move out of the path of nut 38 since it is disengaged from rotating with shaft 28. The corresponding surfaces of rotating wedge element 36 and nut 38 will collide and a void (see Fig. 13b) will exist between respective mating surfaces as the rotating wedge element 36 will not shift back to the position required to allow nut 38 to travel to the closed position of door 12. When upwardly moving nut 38 collides with wedge element 36, now not rotating due to disengagement of key 50, wedge element 36 abuts hard against thrust block 46 restricting any further movement of nut 38 and hence restricting shaft 28 from rotating which in turn limits closure of door 12 relative to door jamb 14. As can be seen from Figs. 3 and 8, key 50 is held in its normally engaged position within key receiving slot 48 by means of a tripping arm 52 which holds down a spring mechanism 54 which is biased to the retracted state of key 50. Tripping arm 52 is preferably operated by a solenoid 56, but may be operated directly or indirectly in association with any other suitable mechanical or electrical means (not shown). Tripping arm 52 preferably pivots about a pivot point 53 as solenoid 56 is activated, which in turn disengages contact between tripping arm 52 and spring mechanism 54, thereby retracting key 50 out of key receiving slot 48 (Figs. 13a and 13b) against the action of spring mechanism 54. A pin (not shown) supports tripping arm 52 at pivot point 53, enabling the pivotable movement of tripping arm 52. This pin is arranged such that it will move with shaft 28 as door 12 is opened and closed, since tripping arm 52 must also move with shaft 28 to enable constant contact with spring mechanism 54. In a preferred embodiment (not shown) the pin is affixed to the top of shaft 28 above support 34, thereby moving with shaft 28 as door 12 is opened and closed. Solenoid 56 may also move with shaft 28 and therefore may also be affixed to shaft 28 in a similar manner to that of the pin. It should be understood that many variations enabling support and movement of tripping arm 52 and/or solenoid 56 could achieve a similar result to that just discussed and, as such, the invention is intended to include these variations and is not intended to be limited to the example given. Solenoid 56 is controlled by a control device 58 (preferably positioned within guideway 24), which is powered by a power supply 60 preferably housed within guideway 22. It is to be understood that control device 58 may include any components that a person skilled in the art may deem to be suitable such as, for example, logic chips and related electronics, and as such the specific components required are not essential to the present invention. Similarly power supply 60 may be any suitable power supply means, such as a battery or a mains supply regulated by a regulator and therefore the choice of power supply 60 is also not essential to the invention. In the non-obstructed mode of operation of device 10 (Figs. 3 to 11), tripping arm 52 is positioned such that it holds down spring mechanism 54 and in turn engages key 50 in the normal, non-powered state of solenoid 56. Thus solenoid 56 requires no power to maintain tripping arm 52, and hence key 50, in engagement with rotating wedge element 36. As best seen in Figs. 13a and 13b, when activated solenoid 56 moves tripping arm 52 which pivots tripping arm 52 about pivot point 53, causing tripping arm 52 to release spring mechanism 54 and in turn retract key 50 against the action of spring mechanism 54 as it returns to the rest position. As previously discussed solenoid 56, tripping arm 52, spring mechanism 54 and key 50 are all preferably arranged such that they rotate with shaft 28 of device 10 to facilitate the normal engagement and operable disengagement of key 50 from rotating wedge element 36 at varying stages of opening and closing of door 12. As explained above, once key 50 is retracted rotating wedge element 36 will no longer rotate with shaft 28 and, as a result thereof, closure of door 12 will be limited. Until such a time that key 50 is re-engaged with rotating wedge element 36, door 12 will not be able to be closed. To reset device 10 and to therefore return to normal operation of door 12 wherein it can again be closed as desired, device 10 is provided with a reset mechanism 62. As best seen in Figs. 4 and 9, reset mechanism 62 is preferably a mechanically operable arm accessible from outside of guideway 26, but may be any other suitable mechanical or electrical or electronic means able to achieve the same result. Upon activation reset mechanism 62 is able to drive spring mechanism 54 downwards, which allows tripping arm 52 to return to its rest position, preferably in cooperation with a tripping arm spring (not shown), wherein tripping arm 52 again holds spring mechanism down and in turn engages key 50. A sensor 64 is preferably mounted within guideway 24 and cooperates with a sensor focusing device 66 which protrudes from guideway 24. Sensor 64 is typically a heat or motion sensor such as a passive infrared (PIR) device, a photosensor, a microwave sensor or any suitable combination, but may be any other suitable sensor which detects movement or changes in temperature. Sensor 64 detects the presence of an obstruction within gap 16. If sensor 64 is a photosensing device a reflector (not shown) may also be positioned at the bottom of door 12 to reflect a beam 68 (Fig. 1) emitted from sensor 64 through sensor focusing device 66. If sensor 64 is a photosensing device or any other suitable active detector, sensor focusing device 66 is utilised to spread or concentrate beam 68 in the required area within gap 16. Alternatively, if sensor 64 is a PIR device, sensor focusing device 66 is a lens which is utilised to focus and direct infrared energy to sensor 64. Sensor 64 cooperates with control device 58 connected to power supply 60 which controls operation of solenoid 56 and by association the disengagement of key 50. The operation of device 10 will now be described. In Figs. 1 & 7 door

12 is shown open, with no obstruction within gap 16 formed between door 12 and adjacent door jamb 14. Device 10 with sensor 64 is preferably fitted at a point high up on the door 12 relative to the floor (not shown) to ensure protection for persons of all heights. Key 50 is normally engaged, as shown in Figs. 3 to 11, since no obstruction in the path of beam 68 is detected by sensor 64. Tripping arm 52 will continue to hold key 50 in engagement with rotating wedge element 36 by means of holding spring mechanism 54 in its biased state. If no obstruction is detected then door 12 can be fully closed, as shown in Figs. 2 to 6, and sensor focusing device 66 will be located between mounting plates 18,20. Fig. 12 shows an obstruction 70, as for example a child's finger, located in gap 16. As door 12 swings closed in the direction of arrow a, finger 70 is sensed by sensor 64. If device 10 incorporates a photosensor as sensor 64 which cooperates with a reflector (not shown) positioned at the bottom of door 12, then finger 70 is sensed when beam 68 (Fig. 1) between sensor 64 and the reflector is broken. Sensor 64 signals control device 58 to activate solenoid 56 which trips tripping arm 52 releasing the action of spring mechanism 54 and in turn disengaging key 50 (see Figs. 13a and 13b) from rotating wedge element 36. As door 12 moves further in the direction of arrow a to the closed position, rotating wedge element 36 no longer rotates with shaft 28, which causes upwardly moving nut 38 to collide with rotating wedge element 36 which abuts hard against thrust block 46 stopping nut 38 from travelling upwardly any further relative to shaft 28. Any further closing of door 12 is therefore restricted, since shaft 28 in association with wedge element 36 and nut 38 restricts any further pivotable movement between mounting plates 18,20 about guideways 22,24,26. Thus finger 70 will not be crushed between door 12 and adjacent jamb 14. Key 50 remains in its retracted state until being reset as explained earlier. Alternatively, reset mechanism 62 could be replaced with a reset switch (not shown) which operates additional components (not shown), for example a further solenoid, to electrically actuate re-engagement of key 50. It may also be desirable for control device 58 to automatically re-engage key 50 upon sensor 64 detecting removal of finger 70. In Figs. 3 to 13b tripping arm 52 and spring mechanism 54 of device 10 are shown arranged off-center to the axis of rotation of shaft 28. In an alternative embodiment, as shown in Figs. 14a and 14b, tripping arm 52 and spring mechanism 54 can be arranged axially with respect to shaft 28 to facilitate manufacture of device 10. Referring to Figs. 14a and 14b, which show device 10 in a pre-activated and activated state respectively, it can be seen that key 50 is operably engaged and disengaged with rotating wedge element 36 by spring mechanism 54 which is positioned on top of shaft 28 above support 34 of guideway 26. Spring mechanism 54 cooperates with key 50 via a rod 55 which passes through an aperture 57 in shaft 28. Aperture 57 is axially located with respect to the direction of rotation of shaft 28 and has an enlarged opening 59 to one side of shaft 28 relative to key 50. Enlarged opening 59 provides a suitable area for key 50 to be engaged and disengaged with rotating wedge element 36 by the action of spring mechanism 54 and rod 55. Although not shown device 10 may include a compression spring or the like horizontally arranged between respective vertical mating surfaces 72, 74 (see Fig. 15) of rotating wedge element 36 and nut 38. This spring (not shown) may be utilised to urge rotating wedge element 36 and nut 38 apart relative to their vertical mating surfaces 72, 74 during operation of device 10. It has been found that over time through continued use of device 10 that wear and build-up relative to mating surfaces 72, 74 can hinder operation of device 10. By utilising a compression spring or the like disposed between vertical mating surfaces 72, 74, proper unhindered operation of device 10 can be ensured throughout its life. If a compression spring disposed between surfaces 72, 74 is used with device 10 this spring will urge rotating wedge element 36 and nut 38 of device 10 to move as desired during opening and closing of door 12 relative to jamb 14. Such a compression spring is merely a preferred way of guaranteeing that device 10 will continue to operate as intended throughout its life. It should be understood that many other similar means could be used to achieve the same result. Device 10 may also include an additional sensor (not shown) strategically located on or around door 12 or door jamb 14. This additional sensor can communicate with control device 58 to also activate solenoid 56 to disengage key 50. If the additional sensor is fitted to the non-hinged side of door 12 it could prevent finger injuries between the opposite door jamb (not shown) and the non-hinged side of door 12. Another option that could be included in device 10 is a device (not shown) for detecting the position of the door 12 in relation to its jamb 14. This device could be used to detect whether door 12 is opened far enough for a finger 70 to be inserted into gap 16. The calculation of this distance, or crucial angle, upon which the door 12 becomes a potential danger could be useful for controlling when sensor 64 becomes active, which could be utilised to reduce power consumption of device 10. In this preferred construction of device 10, control device 58 may only allow sensor 64 to start detecting obstructions when door 12 is within, for example, 30 degrees of door jamb 14, and thus power consumption could be greatly reduced. Although explained in detail as being a separate device for adaptation/association to any door or window jamb 14, it is to be understood that device 10 can simply be a modified hinge wherein mounting plates 18,20 are respective hinge leaves and guideways 22,24,26 are respective cooperating hinge knuckles for effecting the required pivotable hinge movement. It is therefore to be understood that one or more devices 10 can simply be used as a replacement for any hinge in any one of many varying situations in which two members 12, 14 are adapted to be pivotably movable relative to one another and wherein it is desired to be able to restrict the pivotable movement between the members 12, 14 upon an obstruction 70 entering the gap 16 formed therebetween. It should be understood that, although device 10 of the present invention has been described as having three cooperating guideways or hinge knuckles 22, 24, 26, device 10 may alternatively have only two guideways, or may have more than three guideways depending on the application of device 10. For example, if device 10 was to be embodied with two guideways such as only guideways 24 and 26 (not shown), power supply 60 of device 10 could be located alongside control device 58 in guideway 24. In this alternative embodiment (not shown), bearing 30 would not be required and mounting plates 18, 20 would merely need to be attached to a respective guideway 24, 26. It should therefore be evident that various modifications and changes can be made without departing from the broader scope of the invention. Finally, although preferred embodiments have been described with reference to a door or window 12 and a door or window jamb 14, it is to be understood that the device 10 of the invention may also be applied to any other pivoting device e.g. folding doors, motor vehicle doors, motor vehicle bomiets, etc. The invention will be understood to embrace many further modifications, as will be readily apparent to persons skilled in the art and which will be deemed to reside within the broad scope and ambit of the invention, there having been set forth herein only the broad nature of the invention and certain specific embodiments by way of example.

Claims

1. A device for limiting closure of a gap between two relatively movable members when an obstruction protrudes into said gap, said device including: a first component adapted to be associated with a first of said two relatively movable members; a second component adapted to be associated with the other of said two relatively movable members and to be pivotably movable relative to said first component; at least one sensor to detect said obstruction in said gap; and means adapted to be operable when said at least one sensor detects said obstruction to restrict said relative movement between said first and second components to limit closure of said gap between said two relatively movable members.

2. The device as claimed in claim 1, wherein said means adapted to be operable includes a mechanism associated with at least one of said first or second components, said mechanism being adapted to be operable in order to restrict said pivotable movement between said first and second components about their pivot.

3. The device as claimed in claim 1 or claim 2, wherein said pivotable movement between said first and second components is effected in association with at least one shaft.

4. The device as claimed in claim 3, wherein said mechanism includes at least one first wedge component associated with and influenced by said at least one shaft and at least one further wedge component operable to be independent of said at least one shaft and adapted to be capable of wedging said at least one first wedge component associated with said at least one shaft in order to restrict said pivotable movement between said first and second components.

5. The device as claimed in claim 4, wherein said at least one first wedge component and said at least one further wedge component have substantially matched crescent-shaped mating surfaces.

6. The device as claimed in claim 4 or claim 5, wherein said at least one first wedge component is internally threaded and is influenced by a worm gear formed on said at least one shaft.

7. The device as claimed in claim 6, wherein said at least one first wedge component is adapted to be movable up and down said worm gear formed on said at least one shaft but is restricted from rotating relative to said at least one shaft by a groove formed on said at least one first wedge component that receives a rail formed on one of said first or second components of said device.

8. The device as claimed in any one of claims 5 to 7, wherein said at least one first wedge component contacts said at least one further wedge component when substantially no gap exists between said two relatively movable members, such that substantially no void exists between said mating surfaces of said at least one first and said at least one further wedge components.

9. The device as claimed in claim 7 or claim 8, wherein said at least one first wedge component moves down said worm gear formed on said at least one shaft when said two relatively movable members are moved to create said gap.

10. The device as claimed in claim 9, wherein said mating surfaces of said at least one first wedge component and said at least one further wedge component remain in partial contact with one another even when said gap exists between said two relatively movable members.

11. The device as claimed in any one of claims 7 to 10, wherein said at least one first wedge component moves up said worm gear formed on said at least one shaft when said two relatively movable members are moved so that substantially no gap exists between said two relatively movable members.

12. The device as claimed in any one of claims 4 to 11 , wherein said at least one further wedge component is adapted to be movable with said at least one shaft until said obstruction is detected in said gap, and wherein upon detecting said obstruction in said gap said at least one further wedge component of said device is adapted to be independent of said at least one shaft.

13. The device as claimed in claim 12, wherein when said at least one further wedge component is adapted to be independent of said at least one shaft, said at least one further wedge component restricts movement of said at least one first wedge component moving upward with said at least one shaft by acting against said at least one first wedge component and restricting any further upward movement, and wherein said restricted upward movement of said at least one first wedge component restricts said pivotable movement between said first and second components of said device about said at least one shaft, which in turn restricts said relative movement between said two relatively movable members.

14. The device as claimed in claim 12 or claim 13, wherein said at least one further wedge component is adapted to be independent of said at least one shaft in association with at least one key.

15. The device as claimed in claim 14, wherein said at least one key is operable in association with at least one solenoid and/or at least one resiliently biased means.

16. The device as claimed in any one of the preceding claims, wherein said device includes control means to automatically resume non- restricted movement between said first and second components after said obstruction has been removed from said gap in order to resume normal non- restricted movement between said two relatively movable members.

17. The device as claimed in any one of claims 1 to 15, wherein said device includes reset means operable to reset said mechanism after said obstruction has been removed from said gap, in order to resume non-restricted operation of said device and to allow non-limited movement between said two relatively movable members.

18. The device as claimed in any one of the preceding claims, wherein said at least one sensor is a heat or motion detector such as a passive infrared (PIR) device, an active motion sensor such as a light, microwave or sound emitting device, or any suitable combination thereof.

19. The device as claimed in any one of the preceding claims, wherein said at least one sensor is a photosensor, and wherein said device further includes a reflector means, positioned at any suitable location, whereby said photosensor senses an obstruction if its emitted beam between said photosensor and said reflector means is breached.

20. The device as claimed in any one of the preceding claims, wherein one of said two relatively movable members is a door or window and the other of said two relatively movable members is a door or window jamb.

21. The device as claimed in any one of the preceding claims, wherein said device is powered by battery means or is hard- wired and powered by a mains supply.

22. The device as claimed in any one of the preceding claims, wherein said device is a hinge and wherein said first and second components are first and second hinge leaves respectively.

23. The device as claimed in claim 22, wherein each of said first and second hinge leaves includes at least one cooperating knuckle, formed along a common edge, to allow for said pivotable movement between said first and second hinge leaves in association with said at least one shaft.

24. The device as claimed in claim 23, wherein said mechanism of said hinge is associated with at least one of said knuckles of said first or second hinge leaves and is adapted to be able to restrict said pivotable movement between said first and second hinge leaves relative to said at least one shaft.

25. The device as claimed in claim 24, wherein said mechanism of said hinge is housed within said at least one knuckle of said first or second hinge leaves.

26. The device as claimed in claim 25, wherein said mechanism of said hinge is capable of restricting said pivotable movement between said first and second hinge leaves by restricting the rotational movement of said at least one shaft relative to said knuckle housing said mechanism.

27. The device as claimed in any one of claims 23 to 26, wherein said at least one sensor and any other required components of said hinge are housed within said hinge or any of said at least one knuckles of said first or second hinge leaves so that said hinge may substantially resemble a conventional hinge.

28. A method for limiting closure of a gap between two relatively movable members when an obstruction protrudes into said gap, said two relatively movable members being movable in association with a first component adapted to be associated with a first of said two relatively movable members and a second component adapted to be associated with the other of said two relatively movable members and to be pivotably movable relative to said first component, said method including the steps of: monitoring said gap for said obstruction in said gap by said at least one sensor; and restricting said pivotable movement between said first and second components relative to their pivot when said at least one sensor detects said obstruction to limit closure of said gap between said two relatively movable members.

29. The method as claimed in claim 28, wherein said two relatively movable members resume non-restricted operation automatically upon said obstruction being withdrawn from said gap.

30. The method as claimed in claim 28, wherein said two relatively movable members resume non-restricted operation upon manually operating a reset mechanism.

31. The method as claimed in any one of claims 28 to 30, wherein said first and second components are adapted to be pivotably movable in association with at least one shaft.

32. The method as claimed in claim 31 , wherein said pivotable movement between said first and second components is restricted in association with at least two wedge components which restrict said pivotable movement between said first and second components by preventing relative movement about their pivot relative to said at least one shaft.

33. The method as claimed in claim 32, wherein said at least two wedge components have substantially matched crescent-shaped mating surfaces.

34. The method as claimed in claim 33, wherein a first of said at least two wedge components is adapted to move up and down said at least one shaft in association with at least one worm gear, wherein a second of said at least two wedge components is adapted to rotate with said at least one shaft until said obstruction is detected in said gap, at which time said second wedge component is independent of said at least one shaft, and wherein when said second wedge component is independent of said at least one shaft said second wedge component restricts upward movement of said first wedge component which restricts said pivotable movement between said first and second components.

35. The method as claimed in any one of claims 32 to 34, wherein said at least two wedge components are operable in association with at least at least one key, at least one solenoid and/or at least one resiliently biased means.

36. The method as claimed in any one of claims 28 to 35, wherein said at least one sensor is a heat or motion detector such as a passive infrared (PIR) device, an active motion sensor such as a light, microwave or sound emitting device, or any suitable combination thereof.

37. The method as claimed in any one of claims 28 to 36, wherein one of said two relatively movable members is a door or window and the other of said two relatively movable members is a door or window jamb.