AU2009200110A1 - Improved latch assembly having rotatable latch element - Google Patents

Description

P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title: "IMPROVED LATCH ASSEMBLY HAVING ROTATABLE LATCH ELEMENT" The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 LATCH ASSEMBLY INCORPORATING A ROTATABLE LATCH ELEMENT This invention relates to a latch assembly incorporating a rotatable 5 latch element for use with closure members such as doors or gates. In particular, the latch assembly of the invention is particularly applicable to a door or gate which is pivotally mounted to a suitable mount such as a post or frame. In this arrangement, a fixed component of the latch assembly incorporating the rotatable latch element is mounted to a fence post or 10 support frame. A rotatable latch assembly incorporating a rotatable latch element or catch is described in US Patent Publication 20080098658 and refers to a self-latching gate latch for securing a gate. The gate latch is mounted to a 15 fence post or gate post. The rotatable catch extends from the gate latch and is aligned in a closed position when the gate door is shut wherein the catch partially encloses a gate door or fence post when closed. Engaging a release switch allows the catch to rotate in a horizontal plane in either direction. In other words, the catch may rotate horizontally in two directions 20 relative to the closed position. When opened in either direction, the gate latch will automatically self-latch the catch when it has rotated back to the closed position. Reference also may be made to US Patent 5,688,003 which refers to 25 a retaining latch for a water pit gate which has a latch plate rotatably mounted to each end of the top of the gate and a recessed opening in the gate frame. The latch plate is provided with a plurality of steps to engage the recessed opening so that as the latch plate is rotated alternate steps of the latch plate are engaged by the recessed opening. 30 - Reference may also be made to US Patent Publication 20079296226 wherein a latch assembly is described having a latch and a base portion 2 where the latch is selectively connected to the base portion and pivotable about the base portion along a first axis. There is provided a cam mechanism for securing the latch such that the latch is secured for rotation and support for a door of a vehicle along a second axis. 5 Reference also may be made to a gate latch described in US Patent 4,083,591 which has a latch finger secured to a gate which passes through a hollow body of a latch secured to a gate post which engages with one or more pawls rotatably mounted in the body so as to trap the latch finger. 10 Reference may also be made to US Patent 5,362,116 which describes a self-latching device having a latch arm arranged to be attached to one of two members movable relative to each other. A retaining element incorporating a permanent magnet is mounted to the other member. The 15 latch arm is spring biased into a retracted position and can also move to a latched position. The latch arm is caused to move by the magnetic field generated by the magnet into the latched position where any substantial relative movement of the two members is prevented by the latch arm engaging the retaining element. The latch arm is only movable axially and 20 does not incorporate a rotatable latch element. It is therefore an object of the invention to provide a rotatable latch assembly which is particularly adapted for closure gates of swimming pools and which provides for release between a latch arm and a rotatable latch 25 arm as a member for use as a retaining element using a release mechanism which is inaccessible to young children. US Patent 5,362,116 does not use a rotatable latch element which is considered advantageous for efficient use in swimming pool gates and 30 hence, are not relevant to the present invention. This is the sake of structural or functional simplicity with regard to the first embodiment of the present invention as described hereinafter or for spreading impact loads 3 when the rotatable latch element is in a locked position over a much greater surface area having regard to the second embodiment of the present invention as described hereinafter. The remainder of the prior art discussed above was not particularly adapted for closure gates for swimming pools as 5 the release mechanism was often accessible to young children, or otherwise was not suitable for efficient latching or closing of a rotatably or pivotally mounted gate or alternatively, had a complicated operating mechanism. The rotatable latch assembly of the present invention has a movable 10 element and a fixed element wherein the movable element is attached to a rotatably or pivotally mounted door or gate and the fixed element is attached to a stationary member such as a fence post, gate post or support frame. The movable element is particularly adapted to support a gate panel such as a glass panel which may be interposed between opposed plates of the 15 movable element although this is not essential. The movable element may also have a latch member which in use, engages with a rotatable latch element of the fixed assembly. The rotatable latch element is rotatably mounted on the fixed element for movement between an open position and a latched or closed position and such movement is caused by impact with the 20 latch member. Preferably the latch member may be a latch arm, hook or plate. In a first embodiment of the invention, the rotatable latch element is a rotatable cam element which may be an elongate housing for 25 accommodating a pivot pin or bolt and which has one or more rib(s) or outwardly extending protrusion(s) which may engage with corresponding recesse(s) located in an internal surface of a channel member of the latch arm or plate of the movable element. The rotatable cam element may also have a cam protrusion for engaging with the latch arm or plate to initiate 30 rotation of the rotatable latch element. The channel member may be C shaped, U shaped, Y shaped or W 4 shaped as the case may be. Upon contact of the outwardly extending protrusion(s) with the corresponding recesse(s) of the latch arm hook or plate the rotatable latch element may then be rotated to a closed or latched position with at least one rib or protrusion firmly engaged or wedged in a 5 corresponding recess. In this embodiment, the rotatable latch element may also have a nose part engaged in a corner of the channel member. In a second embodiment, the rotatable latch element may support one or more locking pins wherein the or each locking pin may incorporate a 10 magnet, which in use, is repelled by a magnet located in the movable element. The arrangement is preferably such that the rotatable latch element incorporates a pair of opposed magnetised locking pins which are displaced axially in the unlocked position from an axis formed by one or more release members such as buttons or knobs each having a shank which is 15 axially aligned with each locking pin in the closed or latched position. The angular movement of each locking pin from the unlocked to locked position may be caused by the magnetic repulsion described above. In this particular embodiment the fixed element may have a housing which provides a pair of sockets for each of the shanks of the release members. In this embodiment 20 the rotatable latch element also may be supported by a rotatable pin or bolt which extends through the housing of the fixed element. Reference may also be made to a preferred embodiment(s) of the invention as shown in the attached drawings wherein: 25 FIG 1 represents an exploded view of a latch assembly constructed in accordance with the first embodiment of the invention; FIG 2 represents an assembled perspective view of a fixed element of 30 the latch assembly shown in FIG 1 and also shows a movable element of the latch assembly shown in FIG 1 moving towards the fixed element; 5 FIGS 3, 4, 5, 6, 7 and 8 show the various sequence of movements in relation to the movable element approaching the fixed element with the latch plate of the movable element becoming engaged with the rotatable latch element of the fixed element; 5 FIG 9 shows a sectional view through an assembled perspective view of the latch assembly shown in FIG 1; FIG 10 shows an exploded perspective view of a latch assembly in 10 accordance with a second embodiment of the invention; FIG 11 shows a perspective view of a fully assembled view of the latch assembly shown in FIG 10; 15 FIG 12 is a perspective view of the latch assembly of FIG 11 partially broken away to show the latch assembly in an open position; FIG 13 is a detail of area "A" shown in FIG 12; 20 FIG 14 is a detail of area "B" shown in FIG 12; FIG 15 is a plan view showing the latch assembly of FIG 12 showing the movable element clear of the fixed element; 25 FIG 16 is a view similar to FIG 12 showing the receiving element about to engage with the movable element; FIG 17 is a detail of area "C" shown in FIG 16; 30 FIG 18 is a plan view of the latch assembly shown in FIG 16; FIG 19 is a view similar to FIG 12 showing the latch assembly in a 6 locked position; FIG 20 is a detail of location "D" shown in FIG 18; 5 FIG 21 is a plan view of the latch assembly shown in FIG 18; FIG 22 is a view similar to FIG 12 showing the latch assembly in the process of being unlocked; 10 FIG 23 is a view similar to FIG 22 of the latch assembly from a different orientation; FIG 24 is a detail of location "E" shown in FIG 22; 15 FIG 25 is a detail of location "F" shown in FIG 23; FIG 26 is a view similar to FIG 12 showing the latch assembly being unlocked; 20 FIG 27 is a view of the latch assembly shown in FIG 26 from a different orientation; FIG 28 is a detail of location "G" shown in FIG 26; 25 FIG 29 is a detail of location "H" shown in FIG 27; FIG 30 is a view similar to FIG 12 showing the latch assembly in a fully open position; 30 FIG 31 is a detail of location "I" shown in FIG 30; FIG 32 is a plan view of the latch assembly shown in FIG 11; 7 FIG 33 is a sectional view through line A-A of FIG 32 showing the latch assembly in a locked position; FIG 34 is a perspective view of the latch assembly of the invention 5 with an outer wall of the housing for the fixed element removed for clarity; and FIG 35 is a detail of location "X" shown in FIG 32. 10 The latch assembly 10 shown in FIG 1 - 9 has a movable element 11 and a receiving or fixed element 12. The movable element 11 includes a casing 13 having an outer component 14 and an inner plate 15. Outer component 14 has a pair of protrusions 16 and 17 having screw threaded attachment apertures 18 and 19 for retention of screw threaded fasteners 15 (not shown). Outer component 14 also has flange 20. Inner plate 15 has a locating protrusion 21 which engages in a corresponding aperture or recess (not shown) in latch plate 22. Inner plate 15 also has apertures 23 and 24 corresponding to apertures 18 and 19 of outer component 14. 20 Latch plate 22 has a channel 55 shown in FIG 2 and a rear wall 25 as well as end wall 26. There is also provided intermediate wall 27. There is also shown adjustment aperture 28. The rotatable latch element 30 which forms part of fixed element 12 25 has a cylindrical sleeve 31 having internal bore 29 and outwardly extending ribs or protrusions 32 and 33. Rib 32 as shown in FIGS 3 - 8 is longer than rib 33 in plan view. There is also provided spring 34. There is also shown latch support 35, which has top and bottom sockets 36 and 37, web 38 and arm 39 extending away from web 38. The function of web 38 is to only 30 provide latch member with a limited amount of rotation, i.e. about 90* - 120*. The fixed element 12 also has a housing 41 which supports a 8 rotatable pin 42 which extends through a pair of apertures 43 and 44 located in horizontal flanges 45 and 46 of housing 41. Housing 41 also has a mounting plate 8 for attachment to a post of corresponding arcuate shape. There is also shown inner flange 7 best shown in FIG 9. There is also 5 provided movable knob 47 which moves in slot 49. There is also provided cover plate 51 which engages with housing 41 as shown in a snap fit for clipped relationship. There is also shown apertures 42 in mounting plate 8 for attachment to a gate post (not shown). There is also provided end wall 48. 10 When assembled as shown in FIG 2 pin 42 extends through an interior 52 of spring 34 and into internal bore 29 of cylindrical sleeve 31. Pin 42 has a lower locating protrusion 54 which locates in corresponding aperture 44. 15 Also in FIG 2 the movable element 11 fixed to a door gate 9 has a latch plate 22 attached to casing 13 by the use of screw threaded fasteners (not shown) extending through mating apertures 18 and 23 and 19 and 24 shown in FIG 1. Also arm 39 engages with a mating slot (not shown) in knob 20 47. FIG 3 - 8 show the co-operation between movable element 11 and fixed element 12. In FIG 3 the movable element 11 is substantially clear of fixed element 12 and is moving towards a closed or latched position wherein 25 rotatable latch element 30 engages in channel 55 of latch plate 22. Channel 55 is also provided with notch 56. In FIG 4, rotatable latch 30 rotates on bearing pin 42 by cam protrusion flange 27 impacting on short rib 33, as shown. In FIG 5, rotatable 30 latch 30 continues to rotate until it contacts end wall 26 of latch plate 22 and also strikes inner flange 7 of housing 41. This causes rotatable latch 30 to rotate in an opposing direction as shown in FIG 6 and lobe or nose 57 of 9 rotatable latch 30 contacts an inner surface 58 of channel 55. This movement continues as shown in FIG 7 wherein short rib 33 locates in notch 56 as shown with lobe or nose 57 still contacting inner surface 58. In FIG 8, it will be noted that protrusion 33 is firmly wedged in notch 56 and this is 5 facilitated by lobe or nose 57 and adjacent surface 59 of rotatable latch 30 abutting inner surface 58. This corresponds to a latched or locked position with latch plate 22 firmly engaged with fixed element 12. It will also be appreciated that spring 34 biases latch 30 to the closed or latched position. 10 Subsequently, movement of grip knob 47 upwardly in slot 49 causes upper movement of rotatable latch 30 and its associated support 35 upwardly along pin 42 to release movable element 11 from engagement with fixed element 12. This is facilitated by arm 39 of latch support 35 engaging in a recess or notch (not shown) in grip knob 47. 15 FIG 9 shows a sectional view which corresponds with FIG 8 and clearly shows the operation of how grip knob 47 moving along slot 49 will release rotatable latch 30 from engagement with latch plate 22. 20 In the second embodiment shown in FIGS 10 - 35, reference is made to FIG 10 showing an exploded perspective view of the relevant components of a latch assembly 60 constructed in accordance with the invention. Latch assembly 60 includes a movable element 61 and a fixed element 62. Movable element 61 may be attached to a movable member such as a gate 25 or a door or more suitably a glass panel 78 shown in FIG 11 and includes a casing 63 having an outer plate 64 with protrusions 65 defining screw threaded apertures 66, a pair of inner cushions or pads made from resilient material 67 and 68 each having attachment apertures 69 and 70 and 71 and 82 respectively, which are each aligned with screw threaded apertures 66 as 30 shown and an inner cover plate 73 having attachment apertures 74 and 75 aligned with screw threaded apertures 66 and corresponding apertures 69, 70, 71 and 72, as shown. There are also shown screw threaded fasteners 10 76 and 77 wherein one fastener 76 extends through aligned apertures 74, 71, 69 and 66 and the other fastener 77 extends through aligned apertures 75, 72, 70 and 66. 5 It is evident that a glass panel 78, as shown in phantom can be slid into a space or gap 79 shown in FIG 11 for retention by fasteners 76 and 77, which pass through co-aligned apertures (not shown) in glass panel 78. There is also provided a latch plate 80 having an adjustment slot 81 and recesses 82 and 83 for retention of circular magnets 84 and 85 which allow 10 magnetic flux to pass through corresponding apertures 86 and 87. Latch plate 80 also has on its rear surface 88 ribs 89 and 90 which engage with corresponding notches or grooves 91 and 92 on cover plate 73. Latch plate 80 also has engagement bar or hook 94. 15 There is also provided latch body 95 having an arcuate recess 96 for abutment with a post (not shown) of corresponding shape. Latch body 95 also includes a slot 97 for passage of engagement bar or loop 94 as shown. Recess 96 also includes attachment apertures 98 for passage of fasteners (not shown) which attach latch body 95 to the post. There is also provided 20 apertures 99 and 100 which are aligned with corresponding apertures 86 and 87 to allow for passage of magnetic flux from magnets 84 and 85. There is also provided fasteners 101 and 102 which extend through aligned apertures 103 and 104 for attachment to housing 105 of fixed element 62. 25 There is also shown a rotatable latch element 106 which has recess 107 for engagement with engagement bar 94 when the latch is in latched or closed position. Latch element 106 also has protrusion 107A for engagement with a torsion spring 108. There is also provided a pair of locking pins 109 and a compression spring 110 which surrounds an 30 associated end of each locking pin 109 in opposed recesses 111 of latch element 106. There is also provided magnets 112 which are each retained in a socket 113 of locking pins 109.

11 There is also shown lock release buttons 114 each having a stem or shank 115 for engagement with corresponding sockets or bores 116 in housing 105. Each shank is surrounded by compression spring 117 and 5 held in place by circlip 118 in recess 120 of shank 115. There is also provided pivot pin 119 engageable in aperture 121 in housing 105. There is also provided lock assembly 122 which comprises lock barrel 123, lock housing or casing 124 and lock cam 125. 10 In FIGS 12 - 14 there is shown the latch 60 in an open position with each locking pin 109 held in an unlocked position via a shoulder 126 on rotatable latch element 106. The locking pin 109 has a pair of protrusions or lugs 127 and 128 best shown in FIG 17, which each hold magnet 112 and are located on each side of socket 113, shown in FIG 10. Between each of 15 protrusions 127 and 128 is a flat bearing surface 128A also best shown in FIG 17. Thus, the bottom surface 129 of shoulder 126 abuts bearing surface 128A to retain each pin 109 in an unlocked position. It will also be appreciated that the torsion spring 108 holds the rotatable latch element 106 in an unlocked or open position so that hook 94 is clear of recess 107 as 20 shown in FIG 15. In FIG 15 there.is also shown the lines of magnetic flux 130 which results in repulsion between movable element 62 and fixed element 61. In FIG 14 is shown compression spring 110 located between adjacent ends of each locking pin 109. 25 In FIGS 16 - 18, there is shown movable element 62 in the process of being locked with fixed element 61 whereby hook 94 engages with recess 107. In FIG 17 it will be noted that locking pins 109 are still held in the unlocked position via shoulder 126 as described above. In FIG 17, there is also shown gap 112B between the adjacent ends of shoulder 126 which 30 provides space for bearing surface 128A and each protrusion 127 and 128 to move axially under the influence of compression spring 110 when free of adjacent shoulder 126. However, FIG 18 shows that as magnets 84 and 85 12 approach magnets 112 in locking pins 109 the repulsive force increases and this causes locking pins 109 to rotate as shown by the arrow in full outline in FIG 17 and thus, become free of engagement with shoulder 126 whereby each pin 109 will move upwardly and downwardly respectively under the 5 influence of compression spring 110. In FIGS 19 - 20 it will be noted that hook 94 is now fully engaged with recess 107 and thus movable element 61 is now fully engaged with and locked with fixed element 62. In FIG 19, each locking pin 109 is now free 10 from shoulder 126 and each locking pin 109 is in full axial alignment with shanks 115 of lock release buttons 124. Thus, each locking pin 109 has rotated about 30* from the position shown in FIG 12 to the position shown in FIG 19 and is in full abutment with shank 115. In FIG 20, it will be appreciated that the magnetic force between magnets 84 and 85 on movable 15 element 62 and magnets 112 on locking pins 109 is at a stage of maximum repulsion enabling the rotation of locking pins 109 as described above. Internal compression spring 110 is now free to push both locking pins axially to the locked position shown in FIG 19. 20 In FIGS 22 - 25, actuation or depression of each of lock release buttons 124 downwardly results in axial movement of each locking pin 109 to the open position shown in FIGS 12 - 14. Such movement is facilitated by engagement of chamfer 131 on rotatable element 106 with chamfer 132 on locking pins 109 as shown in FIG 24. This causes downward axial 25 movement and then angular displacement of each pin 109 as shown by the arrow in bold outline in FIG 25. In FIGS 26 - 29 there is shown partial unlocking of hook 94 with recess 107 of rotatable latch element 106 wherein each locking pin 109 30 returns to engagement with shoulder 126 as shown in FIG 12. Thus, in FIG 29 each pin 109 is moving partly out of alignment with adjacent shank 115, as shown.

13 In FIGS 30 - 31 there is shown the hook 94 released from recess 107 of rotatable latch element 106 as also shown in FIG 15. It will be noted in FIG 31 that each shank 115 is now axially displaced from locking pin 109 5 and that locking pin 109 is again in engagement with shoulder 126. The reason why rotatable element 106 is not movable in the locked position is shown in FIGS 33 - 34, wherein FIG 34 is a section through line A-A of FIG 33. Thus, each pin 109 has a part 109A and 109B respectively 10 held in bore 116 of housing 105 by compression spring 110. These parts 109A and 109B abut the internal surface of bore 116 and hence, are locked in position preventing any rotatable movement of rotatable element 106. In FIGS 34 - 35 there is shown a view of latch assembly 60 in a 15 locked position with hook 94 engaged in recess 107 of rotatable element 106 as shown. In this locked position each pin 109 is shown axially aligned with adjacent shank 115. There is also shown pivot pin 119 having ends 11 9A and 11 9B which is mounted in a bore 11 3A formed in protrusion 107A and bottom protrusion 107B. There is also shown cam 125 in engagement with 20 shoulder 134 of rotatable latch element 106. Rotatable latch element 106 also has a sleeve 135 which has interior passage or socket 111 for retaining each pin 109. It will also be noted in FIG 35 that shoulder 126 is free of engagement with bearing surface 128A of bottom pin 109. 25 Having regard to the above, it will also be appreciated that the rotatable element 106 will rotate freely when in the unlocked position as shown in FIG 15 and if pressure is exerted on the rotatable element 106, it will return to its original position due to the force of the torsion spring 108. When the hook 94 enters recess 107 of the rotatable element 106 this will 30 cause rotation of the rotatable element 106 from the position shown in FIG 15 when in the unlocked position to the locked position shown in FIG 20.

14 It also will be appreciated that when each pin 109 is in the locked position shown in FIG 20 that the rotatable element 106 is prevented from rotating. When in the process of being locked each pin 109 will rotate out of engagement with shoulder 126 by the magnetic force being greater than the 5 functional force exerted by compression spring 110. This will also cause axial movement of each pin 109 to the locked position. When release buttons 114 are actuated this will force pins 109 from being aligned with an associated shank 115 and thus, rotate counter clockwise to the unlocked position, which is facilitated by chamfers 131 and 132. 10 From the foregoing it is shown that the latch assembly of the invention is efficient in use and is of structural and functional simplicity as shown in the first embodiment of FIGS 1 - 9 as well spreading of impact forces over a large surface area as shown in the second embodiment of FIGS 10 - 35.

Claims (15)

1. A latch assembly for use with closure members such as doors or 5 gates including: (i) a movable element in use attachable to the closure member, which has a latch member extending therefrom; and (ii) a fixed element in use attachable to a stationary post or 10 other support member wherein said fixed element includes a rotatable latch element, which is rotatably mounted to the fixed element and which in use, is rotatable from an open position wherein the rotatable latch element is spaced from the latch member to a 15 closed position where the latch member is in abutment with the rotatable latch element.

2. A latch assembly as claimed in claim 1, wherein the fixed element includes a housing for enclosing the rotatable latch element which is pivotally 20 mounted to a pivot pin supported within the housing,

3. A latch assembly as claimed in claim 1 or 2, wherein the housing also includes one or more release members for initiating movement of the rotatable latch element from a latched or closed position to an open position 25 wherein the latch member is spaced or is clear of the rotatable latch element.

4. A latch assembly as claimed in any one of claims 1 - 3, wherein the latch member is in the form of a latch plate having a channel incorporating one or more recesse(s) and the rotatable latch element has one or more 30 protrusion(s) or rib(s) engageable with the recesse(s) when the rotatable latch element is in a latched or locked position. 16

5. A latch assembly as claimed in claim 4, wherein the rotatable latch element also has a cam protrusion which initiates the rotatable movement of the rotatable latch element when the latch plate is adjacent the rotatable latch element. 5

6. A latch assembly as claimed in claims 2, 3, 4 or 5, wherein the pivot pin is surrounded by a helical spring which biases the rotatable latch element to the open position. 10

7. A latch assembly as claimed in claims 1, 2 or 3, wherein the movable element is provided with a magnet which repels one or more magnetised locking pins or members associated with the rotatable latch element to provide a magnetic force which causes movement of the rotatable latch element from an open to a closed position. 15

8. A latch assembly as claimed in claim 7, wherein there is provided a pair of locking pins which when the rotatable latch element is in an open position are each axially displaced from an adjacent axis formed by a pair of release members and when in the closed position said pair of locking pins 20 have undergone angular displacement so as to have an axis which coincides with the axis of-tTe release members.

9. A latch assembly as claimed in claim 8, wherein respective inner ends of each of the locking pins are surrounded by a helical compression spring. 25

10. A latch assembly as claimed in claim 8 or 9, wherein in the closed position each of the locking pins are in abutment with an adjacent shank of the closure member. 30

11. A latch assembly as claimed in claim 10, wherein each of the shanks of the release members are surrounded by a spring biasing each closure member to an upper or non-operational position. 17

12. A latch assembly as claimed in any one of claims 8 - 11, wherein the rotatable latch element incorporates an abutment shoulder for retaining each locking pin in an immovable position when the rotatable latch element is in 5 an open position before movement of each locking pin is initiated by the magnetic force.

13. A latch assembly as claimed in claim 13, wherein there is provided a recess in each locking pin for incorporating a magnet wherein each recess is 10 bounded by a pair of protrusions defining a bearing surface for contact with the abutment shoulder when the rotatable latch element is in the open position.

14. A latch assembly as claimed in any one of claims 7 - 13, wherein the 15 rotatable latch element is retained in the open position by a torsion spring before moving to the closed position.

15. A latch assembly as claimed in any one of claims 10 - 14, wherein each locking pin is maintained in a fixed or locked position when the 20 rotatable latch element has moved to the closed position by abutment with said shank in a hollow bore or socket located in the fixed element.