GB2622368A

GB2622368A - A lift lock mechanism

Info

Publication number: GB2622368A
Application number: GB2213336.7A
Authority: GB
Inventors: Evans Samantha; Clements Claire; Brooker Steven
Original assignee: Cubis Systems Ltd
Current assignee: Cubis Systems Ltd
Priority date: 2022-09-13
Filing date: 2022-09-13
Publication date: 2024-03-20
Also published as: GB202213336D0; WO2024056992A1

Abstract

A lift lock mechanism for releasably locking a manhole cover, the lift lock mechanism comprising a latch bolt provided relative to an underside of the cover, a lock body provided relative to a wall of the in-ground chamber and a latch member 13 provided relative to the lock body and movable between a latched position in which the latch bolt is captive and a free position in which the latch bolt is removable from the latch member. A locking member 14 is provided relative to the lock body and movable between a locking position to lock the latch member in the latched position and a released position in which the latch member is movable to the free position. The lift lock mechanism further comprises a threaded locking pin associated with the locking member to force the locking member into the locking position when tightened and to contemporaneously release the locking member from the locking position and lift the cover when loosened.

Description

A LIFT LOCK MECHANISM

Technical Field of the Invention

The present invention relates generally to the field of in-ground chambers and covers and more particularly to a lift lock mechanism for releasably locking a cover relative to an in-ground chamber and elevating the cover in one motion, when unlocking the cover from the in-ground chamber.

Background to the Invention

In-ground chambers with covers are often used to provide access to underground utilities infrastructure such as gas lines, electricity lines, water lines and other infrastructure such as internet cabling and the like The in-ground chamber is usually embedded into a larger structure such as a footpath or sidewalk with the cover provided to be coplanar with the footpath or sidewalk when in the closed condition.

Known in-ground chambers are provided with simple, rotatable latches located below the cover and accessible through one or more openings provided in the cover.

An elongate tool may be inserted into the opening and downwardly to engage with a member or assembly associated with a rotatable latch bar to rotate the latch bar between the latched and unlatched positions These covers can be removed by any person with an appropriate tool.

As the in-ground chambers are provided outside and sometimes in high traffic areas, detritus such as dust and dirt can build up over time between the edge of the cover and the frame within which the cover sits. This detritus can become wedged and compacted in position which greatly increases the difficulty in raising the cover, even when the cover has been unlatched by an operator.

Once unlatched, the cover must then be physically lifted clear of the cover frame within which the cover sits. The covers can be sometimes quite heavy and need to be lifted vertically, which can be difficult enough, but it is exacerbated with there is detritus can become wedged and compacted in position.

It would be a significant advance in the field to provide a mechanism to allow a cover to be releasably locked or latched relative to an in-ground chamber. It would further be an advance in the field to provide a mechanism for allowing the cover to be raised out of the closed position, even when there may be significant amounts of detritus wedged and compacted in between the edge of the cover and the frame within which the cover sits.

Summary of the Invention

According to one aspect of the invention, there is provided a lift lock mechanism for releasably locking a cover relative to an in-ground chamber, the lift lock mechanism comprising.

a) A latch bolt provided relative to an underside of the cover; b) A lock body provided relative to a wall of the in-ground chamber; c) A latch member provided relative to the lock body and movable between a latched position in which the latch bolt is captive and a free position in which the latch bolt is removable from the latch member; d) A locking member provided relative to the lock body and movable between a locking position to lock the latch member in the latched position and a released position in which the latch member is movable to the free position; and characterized in that the lift lock mechanism further comprises: e) A threaded locking pin associated with the locking member to force the locking member into the locking position when tightened and to contemporaneously release the locking member from the locking position and lift the cover when loosened.

Providing a lift lock mechanism for releasably locking a cover relative to an in-ground chamber and also allowing the threaded locking pin to contemporaneously release the locking member from the locking position and lift the cover when loosened allows the locking pin to separate the cover from the cover frame within which the cover sits, even if there is a significant amounts of detritus wedged and compacted in between the edge of the cover and the frame within which the cover sits. This will in turn allow an operator to gip the cover more easily for removal from the opening in the cover frame.

Loosening the threaded locking pin may act to lower the cover into position relative to the in-ground chamber contemporaneously with forcing the locking member into the locking position when tightened Moving the latching member to the latched position may occur contemporaneously with the forcing the locking member into the locking position when tightened.

The lift lock mechanism is preferably provided for releasably locking a cover relative to an in-ground chamber. The in-ground chamber may have any shape, any size and any construction but will typically define an internal volume. The internal volume will preferably be defined by at least one side wall. Each at least one side wall may have an upper edge of the side wall. The respective upper edges of the at least one side wall may be coplanar. The respective upper edges of the at least one side wall may define the upper end of the in-ground chamber. Alternatively, a cover frame may be associated with the at least one side wall of the in-ground chamber to receive the cover.

Where provided, the cover frame may be mounted relative to and/or attached relative to the at least one side wall. The cover frame may define an opening into which the cover is received. An upper surface of the cover may be coplanar with an upper periphery of the cover frame when the cover is in place relative to the in-ground chamber. An outer edge of the cover may be adjacent to a portion of the cover frame.

A clearance gap may be provided on at least one side of the cover in between the outer edge of the cover and an inner portion of the cover frame.

The cover is preferably sized and shaped to fit within the cover frame (or an upper portion of the in-ground chamber) with a clearance gap on at least one side of the cover between the cover and an inner portion of the cover frame (or in-ground 25 chamber).

At least one opening may be provided in, and preferably through the cover to allow access through the cover to the locking pin of the lift lock mechanism. A tool may be used, inserted into or through the at least one opening A rebate or depression may be provided into an underside of the cover about the opening to seat an enlarged head of the locking pin The enlarged head of the locking pin may preferably seat in the rebate or depression and abut a portion of the underside of the cover. An engagement portion provided on the enlarged head of locking pin is preferably accessible through the opening in the cover to allow rotation of the locking pin. The enlarged head of the locking pin will preferably prevent the locking pin passing through the opening and the cover. As the locking pin is loosened, the enlarged head of the locking pin may abut the recess or depression in the underside of the cover to force the cover away from the lock body. The recess or depression is preferably shaped to receive the enlarged head of the locking pin. The enlarged head of the locking pin may rotate within the recess or depression or alternatively, the enlarged head of the locking pin may not rotate within the recess or depression despite the locking pin itself rotating.

A latch bolt may be provided relative to an underside of the cover. The latch bolt may be mounted to or relative to an underside of the cover. The latch bolt may extend laterally outwardly from a central part of the cover. The latch bolt is preferably provided substantially parallel to an upper surface of the cover. The latch bolt is preferably spaced beneath the lower side of the cover to allow clearance for the latch member to engage the latch bolt when the cover is being latched or locked.

The latch bolt is preferably provided within the perimeter of the cover, that is without any portion of the latch bolt extending laterally further than the perimeter of the cover. The latch bolt may have any shape but may preferably be cylindrical. The latch bolt may be mounted relative to an underside of the cover from one end an extend laterally outwardly to a free end. An enlarged portion may be provided at or adjacent to a free end of the latch bolt.

The latch bolt may extend substantially perpendicularly to a side edge of the cover (if the cover is rectangular) or radially oriented relative to the centre of the cover (if the cover is circular).

The latch bolt may be made of any material but a strong and robust material such as a metal is preferred.

A cover retention assembly may be provided on at least one side of the cover. The cover retention assembly may be provided on an underside of the cover, substantially opposite to the latch bolt. The cover retention assembly may include a substantially L-shaped member. The substantially L-shaped member may include a downcomer portion and a laterally extending portion. The laterally extending portion may extend laterally outwardly from the centre of the cover (if the cover is circular) or substantially perpendicular to a side edge of the cover (if the cover is rectangular). An opening may be provided in the at least one side wall of the in-ground chamber and/or the cover frame if provided to receive at least a part of the laterally extending portion.

The substantially L-shaped member may be planar to resist rotation. The opening may preferably correspond with the shape and configuration of the substantially L-shaped member. In one embodiment, the opening may be a slot opening.

Locating the laterally extending portion into the opening may act to fix the side of the cover relative to the at least one side wall and/or cover frame on one side of the cover and the lift lock mechanism can then be used to latch and lock the cover relative to the in-ground chamber, the cover retention assembly may be provided with a laterally extending mounting portion, extending in a direction opposite to the laterally extending portion, and used to mount the cover retention assembly relative to the cover, for example using fasteners such as threaded screws or bolts.

The lift lock mechanism may include a lock body provided relative to a wall of the in-ground chamber. The lock body may be provided on the cover frame, if provided, at the top of the at least one side wall of the in-ground chamber. The lock body will preferably be provided on one lateral side of the in-ground chamber.

The lock body may comprise a hollow body with an associated, removable faceplate in order to close the lock body. The components of the lift lock mechanism including the latch member, locking member and threaded locking sleeve which receives the threaded locking pin may be located within the lock body.

The lock body may mount one or more pivot pins or shafts about which one or more of the components pivot or rotate. For example, in one embodiment, the latch member and locking member may pivot around a respective pivot pin, each of which is mounted relative to the lock body.

As mentioned above, the lock body preferably mounts a threaded locking sleeve to receive the threaded locking pin therein to. The threaded locking sleeve is preferably mounted vertically to allow the locking pin to move vertically. A lower edge of the threaded locking sleeve may be aligned with the lower edge of the lock body. An upper edge of the threaded locking sleeve may be spaced from the top of the locking body.

An opening may be provided in the bottom wall of the lock body, below the threaded locking sleeve to allow the length of the locking pin to extend below the lock body when in the locking position. An opening may be provided in the top of the lock body. An abutment end of the locking member may extend above the locking body, through the opening in the top of the lock body when the lift lock mechanism is in the unlocked condition and may be depressed into or through the opening in the top of the lock body by the enlarged head of the locking pin when the locking pin is in the locked position.

An opening may be provided in the upper side of the lock body to allow the latch member or a portion thereof to extend above the lock body when in the unlatched position. When in the latched position, the latch member will preferably be located within the lock body.

The lock body may be mounted within the in-ground chamber relative to an abutment ledge provided on the at least one side wall and/or cover frame to brace the lock body against movement.

The lift lock mechanism may include a latch member provided relative to the lock body and movable between a latched position in which the latch bolt is captive within the lock body and a free position in which the latch bolt is removable from the latch member (and the in-ground chamber).

The latch member will preferably be unitary or provided in one piece. The latch 25 member may be planar. The latch member may include a mounting portion used to mount the latch member relative to the lock body and a receiving portion to receive the latch bolt.

The mounting portion may be mounted relative to a pivot pin or shaft to allow the latch member to pivot or rotate.

An abutment shoulder may be provided on the latch member against which a portion of the locking member abuts when in the locking position to lock the latch member against rotation. The abutment shoulder may be a planar part or side edge of the latch member. The abutment shoulder may be provided relative to the mounting portion of the latch member.

The receiving portion may include a substantially U-shaped opening, open on one side. The receiving portion may include a pair of] aws which are spaced apart from one another to define the substantially U-shaped receiving opening. Each of the jaws may be the same size. Alternatively, an upper jaw may be longer than a lower jaw in order to provide clearance within the lock body for the lower jaw to move, when moving tween the unlatched position and the latched position.

A free end of the respective jaws may be arcuate in order to provide an arcuate entry into the receiving portion. The provision of an arcuate entry may facilitate entry or engagement of the latch bolt into the receiving portion.

The latch member may be pivoted into an upwardly angled position relative to the lock body when in the free position, with the receiving opening in the latch member oriented in upwardly angled position. The receiving opening may be substantially parallel to the plane of the cover when in the latched position. As mentioned above, the latch member may be received within the lock body in the latched position.

The latch member may be biased into the free position. Any mechanism may be provided to bias the latch member into the free position for example a resilient member such as a spring or similar. Where a biasing spring is provided, the biasing spring may be provided relative to or at least partially about the pivot pin or shaft used to mount the latch member relative to the lock body.

The lift lock mechanism may include a locking member provided relative to the lock body and movable between a locking position to lock the latch member in the latched position and a released position in which the latch member is movable to the free position The locking member will preferably be unitary or provided in one piece. The locking member may be planar. The locking member may include a cental mounting portion used to mount the locking member relative to the lock body.

The mounting portion may be mounted relative to a pivot pin or shaft to allow the locking member to pivot or rotate As mentioned above, in use, the locking member will preferably function to lock the latch member in the latched position and to free the latch member to move to the free position when the locking member is unlocked The locking member is preferably mounted within the lock body between the latch member and the threaded locking pin. The locking member is preferably driven in movement by the threaded locking pin into the locked position. The locking member may be biased into the released position. A resilient member or assembly may be provided to bias the locking member into the released position. A spring or similar could be used. Where a spring is used, the spring may be mounted relative to, or partially about a pivot pin or shaft used to mount the locking member within the lock body.

A first L-shaped arrangement may extend from the mounting portion of the lock member in a first direction. The first direction may be toward the threaded locking pin. The first L-shaped arrangement may include an upstand part and a connecting arm. The connecting arm may connect the upstand part to the mounting portion of the locking member.

The upstand part may be substantially parallel to the length of the locking pin when in the released position. An abutment end may be provided at a free end of the upstand part, to abut an enlarged head of the threaded locking pin. The abutment end may be substantially perpendicular to the enlarged head of the threaded locking pin when in the released position and may be angled relative to the enlarged head of the threaded locking pin when in the locking position due to the rotation of the locking member during the locking and unlocking movement.

As mentioned above, the connecting arm preferably connects the upstand part of the first L-shaped arrangement to the mounting portion of the locking member. The connecting arm may be substantially perpendicular to the upstand part and/or substantially parallel with the lock body when in the released position and angled relative to the lock body when in the locked position. The connecting arm may preferably extend from the mounting portion and will preferably be integrally formed therewith. A second L-shaped arrangement may extend from the mounting portion of the lock member in a second direction. The second direction may be opposite to the first direction. The second direction is preferably toward the latch member.

The second L-shaped arrangement may be angled or offset relative to the first L-shaped arrangement. The second L-shaped arrangement may include a downcomer portion and a locking arm portion. The downcomer portion may preferably extend from the mounting portion of the locking member and will preferably be integrally formed therewith. The downcomer portion may be angled relative to the lock body when the locking member is in the released position and be substantially perpendicular to the locking body when in the locked position The locking arm portion may be substantially parallel to the lock body when in the locking position and angled relative to the locking body when in the released position. The locking arm portion may include an abutment edge or surface to abut the abutment shoulder provided on the latch member when the locking member is in the locking position. The locking member may preferably be held in the locking position by the abutment of the enlarged head of the threaded locking pin against the abutment end of the first L-shaped arrangement which, due to the pivot mount of the locking member will thereby hold the abutment edge or surface of the locking arm portion against the abutment shoulder provided on the latch member when in the locking position.

The lift lock mechanism preferably includes a threaded locking pin associated with the locking member to force the locking member into the locking position when tightened into contemporaneously release the locking member from the locking position and lift the cover when loosened.

The locking pin may preferably be elongate. The locking pin is preferably mounted in the preferred locking sleeve and extend perpendicularly to the lock body.

The locking pin is preferably threaded externally (to correspond to the preferably internally threaded locking sleeve).

The locking pin may be provided with a first, radially larger part or assembly located adjacent to a lower end of the locking pin. The first radially larger part or assembly may function to limit the movement of the locking pin when loosened. The first radially larger part or assembly may be or include a circlip attached to the locking pin.

The locking pin may be provided with a second radially larger part located between the first radially larger part or assembly and the enlarged head of the threaded locking pin. The second radially larger part may be spaced from the enlarged head of the threaded locking pin. The second radially larger part may function to limit the movement of the locking pin when tightened. The spacing between the second radially larger part and the enlarged head of the threaded locking pin may be such that when the second radially larger part abuts an upper end of the preferred locking sleeve, the enlarged head of the threaded locking pin is in the locking position The enlarged head may be provided at an upper end of the threaded locking pin. As mentioned above, in use, the enlarged head may abut the abutment end of the locking member when in the locking position. An upper side of the enlarged head of the threaded locking pin may abut an underside of the cover to force the cover upwardly as the threaded locking pin is loosened. The cover may engage with the enlarged head of the threaded locking pin to move with the threaded locking pin in both directions or alternatively, the cover may move downwardly under the force of gravity as the threaded locking pin is tightened.

An engagement portion may be provided on upper side of the enlarged head/the end of the threaded locking pin to allow the locking pin to be driven in rotation. The enlarged portion may be shaped. The shape of the enlarged portion may configure the enlarged portion to engage with a tool to be used to rotate the threaded locking pin. The enlarged portion may be male (an extension) or female (an opening or depression).

A tool may be provided to engage with the engagement portion. The end of the tool may be provided with shaped portion corresponding to the enlarged portion provided on the locking pin.

The enlarged head of the locking pin may rotate freely about the locking pin, allowing the threaded locking pin to rotate separately from the enlarged head.

Alternatively, the enlarged head may rotate with the locking pin. The locking pin and enlarged head may be formed integrally with one another.

Detailed Description of the Invention

In order that the invention may be more clearly understood one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings, of which Figure I_ is an axonometric view of an in-ground chamber cover frame and cover in the closed condition according to an embodiment.

Figure 2 is a side elevation view of the configuration illustrated in Figure 1, Figure 3 is an axonometric view of the in-ground chamber cover frame and cover shown in Figure 1, in the raised condition Figure 4 is a side elevation view of the configuration illustrated in Figure 2 Figure 5 is a sectional side view of the configuration shown in Figure 1, along line A-A.

Figure 6 is a sectional side view of the configuration shown in Figure 3, along line B-B.

Figure 7 is a detailed view of the RHS of Figure 5 Figure 8 is a details view of the LHS of Figure 5.

Figure 9 is a detailed view of the RHS of Figure 6.

Figure 10 is a details view of the LHS of Figure 6 Figure 11 is a front elevation view of a lift lock mechanism according to an embodiment with the forward wall of the lock body removed, in the unlocked condition.

Figure 12 is a front elevation view of the lift lock mechanism illustrated in Figure 11, in the unlocked condition.

Figure 13 is an axonometric view of the lift lock mechanism illustrated in Figure 11, mounted to an in-ground chamber wall Figure 14 is an axonometric view of the lift lock mechanism illustrated in Figure 12, mounted to an in-ground chamber wall.

Figure 15 is a front elevation view of the lift lock mechanism illustrated in Figure 13.

Figure 16 is a front elevation view of the lift lock mechanism illustrated in Figure 14.

Figure 17 is a front elevation view of the lift lock mechanism illustrated in Figure 13, and showing a tool used to lock and inlock the mechanism Figure 18 is a front elevation view of the lift lock mechanism illustrated in Figure 14, and showing the tool used to lock and inlock the mechanism.

Figure 19 is a front elevation view of the lift lock mechanism illustrated in Figure Figure 20 is a front elevation view of the lift lock mechanism illustrated in Figure Figure 21 is a front elevation view of the configuration in Figure 20 with a forward wall of the lock body removed.

According to the embodiment illustrated, a lift lock mechanism for releasably locking a cover 10 relative to an in-ground chamber is shown. The illustrated lift lock mechanism comprises: a) A latch bolt 11 provided relative to an underside of the cover 10; b) A lock body 12 provided relative to a wall of the in-ground chamber; c) A latch member 13 provided relative to the lock body 12 and movable between a latched position in which the latch bolt 11 is captive and a free position in which the latch bolt 11 is removable from the latch member 13; d) A locking member 14 provided relative to the lock body 12 and movable between a locking position to lock the latch member 13 in the latched position and a released position in which the latch member 13 is movable to the free position.

The illustrated lift lock mechanism further comprises a threaded locking pin 15 associated with the locking member 14 to force the locking member 14 into the locking 10 position when tightened and to contemporaneously release the locking member 14 from the locking position and lift the cover 10, when loosened.

Loosening the threaded locking pin 15 may also act to lower the cover into position relative to the in-ground chamber contemporaneously with forcing the locking member 14 into the locking position, when tightened.

Moving the latching member 13 to the latched position may occur contemporaneously with the forcing the locking member 14 into the locking position when tightened.

In the illustrated embodiment, particularly in Figures 1 to 10, a cover frame 51 for an in-ground chamber is provided. The cover frame Si is located within an upper end of the in-ground chamber, within the sidewaIls of the in-ground chamber which define the internal volume. The cover frame will receive the cover 10.

As shown, the cover frame 51 is configured to be mounted relative to the side walls of the chamber. The cover frame defines an opening (shown in Figure 3) into which the cover 10 is received. As shown in Figures 1 and 2, an upper surface of the cover 10 is coplanar with an upper periphery of the cover frame 51 when the cover 10 is in place relative to the in-ground chamber. An outer edge of the cover is adjacent to a portion of the cover frame 51. A clearance gap may be provided on at least one side of the cover in between the outer edge of the cover 10 and an inner portion of the cover frame 51.

An opening (obscured by tool 52) may be provided through the cover 10 to allow access through the cover 10 to the locking pin 15 of the lift lock mechanism. A tool 52 may be used, inserted into or through the opening as shown.

A rebate or depression 16 may be provided into an underside of the cover 10 about the opening to seat an enlarged head 17 of the locking pin 15. The enlarged head 17 of the locking pin 15 seats in the rebate or depression 16 and abut a portion of the underside of the cover 10. An engagement portion 18 provided on the enlarged head 17 of the locking pin 15 is accessible through the opening in the cover 10 to allow rotation of the locking pin 15. The enlarged head 17 of the locking pin 15 prevents the locking pin 15 passing through the opening and the cover 10.

As the locking pin 15 is loosened, the enlarged head 17 of the locking pin 15 abut the recess or depression 16 in the underside of the cover 10 to force the cover 10 away from the lock body 12, lifting the cover 10 as shown in Figures 3, 4 and 6 As shown in Figures 1 to 10, a latch bolt 11 is provided relative to an underside of the cover 10. The latch bolt 11 may be mounted to or relative to an underside of the cover 10. The illustrated latch bolt 11 extends laterally outwardly from a central part of the cover 10. The latch bolt 11 is substantially parallel to an upper surface of the cover 10. The latch bolt 11 is spaced beneath the lower side of the cover 10 to allow clearance for the latch member 13 to engage the latch bolt 11 when the cover 10 is being latched.

As shown, the latch bolt 11 is provided within the perimeter of the cover 10, that is without any portion of the latch bolt 11 extending laterally further than the perimeter of the cover 10. The latch bolt 11 shown is cylindrical. The illustrated latch bolt 11 is mounted relative to an underside of the cover from one end and extends laterally outwardly to a free end.

The illustrated latch bolt 11 extends substantially perpendicularly to a side edge of the cover 10 as the cover is rectangular.

The latch bolt 11 may be made of any material but a strong and robust material such as a metal is preferred.

As shown in Figures 9 and 10 in particular, a cover retention member 19 is provided on an opposite side of the cover to the lift lock assembly. The cover retention member 19 is also provided on an underside of the cover 10, substantially opposite to the latch bolt 11 The illustrate cover retention member 19 includes a substantially L-shaped member. The substantially L-shaped member includes a downcomer portion 20 and a laterally extending portion 21. The laterally extending portion 21 extends substantially perpendicularly to a side edge of the cover shown. An opening is provided in the cover frame 51 to receive at least a part of the laterally extending portion 21.

A laterally extending mounting portion 22 extends in a direction opposite to the laterally extending portion 21 and is used to mount the cover retention member 19 relative to the cover 10, for example using fasteners such as threaded screws or bolts as shown in Figures 9 and 10.

The cover retention member 19 is planar to resist rotation. The opening in the cover frame 51 corresponds with the shape and configuration of the cover retention member 19, In one embodiment, the opening may be a slot opening. Locating the laterally extending portion 21 into the opening may act to fix the side of the cover 10 relative to the cover frame 51 on one side of the cover 10 and the lift lock mechanism can then be used to latch and lock the cover 10 on the other side of the cover 10.

The lock body may be provided on the cover frame, if provided, at the top of the at least one side wall of the in-ground chamber The lock body will preferably be provided on one lateral side of the in-ground chamber.

The lock body 12 of the illustrated embodiment comprises a hollow body with an associated, removable faceplate in order to close the lock body 12. The components of the lift lock mechanism including the latch member 13, locking member 14 and threaded locking sleeve 23 which receives the threaded locking pin 15 are located within the lock body 12 as shown in Figures 11 and 12.

The lock body 12 mounts a pivot pin about which the latch member 13 and locking member 14 pivot, each of which is mounted relative to the lock body U. As mentioned above, the lock body 12 mounts a threaded locking sleeve 23 to receive the threaded locking pin 15 thereinto. As illustrated, the threaded locking sleeve 23 is mounted vertically to allow the locking pin 15 to move vertically. A lower edge of the threaded locking sleeve 23 is aligned with the lower edge of the lock body 12. An upper edge of the threaded locking sleeve 23 is spaced from the top of the lock body 12. An opening is provided in the bottom wall of the lock body 12, below the threaded locking sleeve 23 to allow the length of the locking pin 15 to extend below the lock body 12 when in the locking position An opening is provided in the top of the lock body 12. As shown in Figure 13, an abutment end of the locking member 14 extends above the lock body 12, through the opening in the top of the lock body 12 when the locking pin 15 is in the unlocked condition and is depressed into or through the opening in the top of the lock body 12 by the enlarged head 17 of the locking pin 15 when the locking pin 15 is in the locked position An opening is also provided in the upper side of the lock body 12 to allow the latch member 13 or a portion thereof to extend above the lock body 12 when in the unlatched position. When in the latched position, the latch member 13 is be located within the lock body 12 as shown in Figures 12 and 14 In the illustrated embodiment, the lock body 12 is mounted within the cover frame 52 relative to an abutment ledge 24 to brace the lock body 12 against movement.

The latch member 13 illustrated is unitary or provided in one piece. The latch member 13 is also planar. The latch member 13 included a mounting portion used to mount the latch member 13 relative to the pivot pin 25 on the lock body 12 to allow the latch member to pivot or rotate, and a receiving portion to receive the latch bolt 13.

An abutment shoulder 26 is provided on the latch member 13 against which a portion of the locking member 14 abuts when in the locking position to lock the latch member 13 against rotation. The abutment shoulder 26 illustrated in Figures 11 and 12, is a planar side edge of the latch member 13.

The receiving portion of the latch member 13 includes a substantially U-shaped opening 27, open on one side. The receiving portion includes a pair ofjaws 28 which are spaced apart from one another to define the substantially U-shaped receiving opening 27. Each of the jaws 28 are the same size.

As shown in Figure 11, the free end of the respective jaws 28 is arcuate in order to provide an arcuate entry into the U-shaped opening 27. The provision of an arcuate entry may facilitate entry or engagement of the latch bolt 11 into the U-shaped opening 27.

The latch member 13 may be pivoted into an upwardly angled position relative to the lock body 12 when in the free position, with the U-shaped opening 27 in the latch member 13 oriented in upwardly angled position as shown in Figure 11.

The U-shaped opening 27 is substantially parallel to the plane of the cover 10 when in the latched position as shown in Figure 12. As mentioned above, the latch member 13 is received within the lock body 12 in the latched position.

The latch member 13 of the illustrated embodiment is biased into the free position (Figure 11) A biasing spring 29 is provided relative to the pivot pin 25 used to mount the latch member 13 relative to the lock body 12 The locking member 14 of the illustrated embodiment is also unitary or provided in one piece. The locking member 14 is planar. The locking member 15 shown includes a central mounting portion used to mount the locking member 14 relative to a pivot pin 30 to allow the locking member 14 to pivot or rotate.

As mentioned above, in use, the locking member 14 functions to lock the latch member 13 in the latched position and to free the latch member 13 to move to the free position when the locking member 14 is unlocked The locking member 14 is mounted within the lock body 12 between the latch member 13 and the threaded locking pin 15. The locking member 14 is driven in movement by the threaded locking pin 15 into the locked position. In the illustrated embodiment, the locking member 14 is biased into the released position by a spring 31 mounted relative to the pivot pin 30 used to mount the locking member 14 within the lock body 12.

A first L-shaped arrangement extends from the mounting portion of the lock member 14 in a first direction toward the threaded locking pin 15. The first L-shaped arrangement includes an upstand part 32 and a connecting arm 33. The connecting arm 33 connects the upstand part 32 to the mounting portion of the locking member 15.

As shown in Figure 11, the upstand part 32 is substantially parallel to the length of the locking pin 15 when in the released position. A terminal abutment end is provided at a free end of the upstand part 32, to abut the enlarged head 17 of the threaded locking pin 15. The abutment end is substantially perpendicular to the enlarged head 17 of the threaded locking pin 15 when in the released position as shown in Figure 11 and is angled relative to the enlarged head 17 of the threaded locking pin 15 when in the locking position, as shown in Figure 12, due to the rotation of the locking member 14 about the pivot pin 30 during the locking and unlocking movement.

As mentioned above, the connecting arm 33 connects the upstand part 32 of the first L-shaped arrangement to the mounting portion of the locking member 14 and is substantially perpendicular to the upstand part 32 and substantially parallel with the lock body 12 when in the released position as shown in Figure 11 and angled relative to the lock body 12 when in the locked position as shown in Figure 12, when in the locking position. The connecting arm 33 extends from the mounting portion and will is integrally formed therewith A second L-shaped arrangement extends from the mounting portion of the lock member 14 in a second direction, opposite to the first direction, toward the latch member 13 The second L-shaped arrangement is angled or offset relative to the first L-shaped arrangement abut the pivot pin 30. The second L-shaped arrangement includes a downcomer portion 34 and a locking arm portion 35. The downcomer portion 34 extends from the mounting portion of the locking member 14 and is integrally formed therewith. The downcomer portion 34 is angled relative to the lock body 12 when the locking member 14 is in the released position as shown in Figure 11 and is substantially perpendicular to the locking body 12 when in the locked position, as shown in Figure The locking arm portion 35 is substantially parallel to the lock body 12 when in the locking position, as shown in Figure 12 and angled relative to the locking body 12 when in the released position as shown in Figure 11. The locking arm portion 35 includes an abutment edge 36 to abut the abutment shoulder 26 provided on the latch member 13 when the locking member 14 is in the locking position. The locking member 14 is held in the locking position by the abutment of the enlarged head 17 of the threaded locking pin 15 against the abutment end of the upstand 32 which, due to the pivot mount of the locking member 15 will thereby hold the abutment edge 36 of the locking arm portion 35 against the abutment shoulder 26 provided on the latch member 13 when in the locking position.

As shown, the locking pin 15 is elongate. The locking pin 15 is preferably mounted in the locking sleeve 23 and extends perpendicularly to the lock body 12. The locking pin 15 is preferably threaded externally to correspond to the preferably internally threaded locking sleeve 23.

The locking pin 15 may be provided with a first, radially larger part located adjacent to a lower end of the locking pin 15 to limit the movement of the locking pin when loosened. The first radially larger part or assembly illustrated is a circlip 37 attached to the locking pin The locking pin 15 may be provided with a second radially larger part 38 located between the circlip 37 and the enlarged head 17 of the threaded locking pin 15. The second radially larger part 38 is spaced from the enlarged head 17 of the threaded locking pin 15 and functions to limit the movement of the locking pin 15 when tightened. The spacing between the second radially larger part 38 and the enlarged head 17 of the threaded locking pin 15 is such that when the second radially larger part 38 abuts an upper end of the locking sleeve 23, the enlarged head 17 of the threaded locking pin 15 is in the locking position as shown in Figure 12.

The enlarged head 17 of he illustrated embodiment is provided at an upper end of the threaded locking pin 15. As mentioned above, in use, the enlarged head 17 may abut the abutment end of the locking member 15 when in the locking position.

An upper side of the enlarged head 17 of the threaded locking pin 15 may abut an underside of the cover 10 to force the cover upwardly as the threaded locking pin 15 is loosened. The cover 10 may engage with the enlarged head 17 of the threaded locking pin 15 to move with the threaded locking pin 15 in both directions or alternatively, the cover 10 may move downwardly under the force of gravity as the threaded locking pin 15 i s tightened.

An engagement portion 18 is provided on upper side of the enlarged head 17 of the threaded locking pin 17 to allow the locking pin 15 to be driven in rotation. The enlarged portion 18 shown is a rectangular extension. The shape of the enlarged portion 18 allows the enlarged portion 18 to engage with the tool 52 to be used to rotate the threaded locking pin 15 The end of the tool 52 is provided with shaped portion corresponding to the enlarged portion 18 provided on the locking pin 15 The one or more embodiments are described above by way of example only. Many variations are possible without departing from the scope of protection afforded by the appended claims.

Claims

CLAIMSA lift lock mechanism for releasably locking a cover relative to an in-ground chamber, the lift lock mechanism comprising a. A latch bolt provided relative to an underside of the cover; b. A lock body provided relative to a wall of the in-ground chamber; c. A latch member provided relative to the lock body and movable between a latched position in which the latch bolt is captive and a free position in which the latch bolt is removable from the latch member; d. A locking member provided relative to the lock body and movable between a locking position to lock the latch member in the latched position and a released position in which the latch member is movable to the free position; and characterized in that the lift lock mechanism further comprises: e. A threaded locking pin associated with the locking member to force the locking member into the locking position when tightened and to contemporaneously release the locking member from the locking position and lift the cover when loosened.
2. A lift lock mechanism as claimed in claim 1 wherein the threaded locking pin acts to lower the cover into position relative to the in-ground chamber contemporaneously with forcing the locking member into the locking position when tightened.A lift lock mechanism as claimed in claim 1 or claim 2 wherein the locking member moves the latching member to the latched position contemporaneously with the forcing the locking member into the locking position when the threaded locking pin is tightened.A lift lock mechanism as claimed in any one of the preceding claims wherein the lock body mounts a pair of pivot pins about which the latch member and locking member pivot respectively.A lift lock mechanism as claimed in any one of the preceding claims wherein the lock body mounts a threaded locking sleeve to receive the threaded locking pin thereinto.A lift lock mechanism as claimed in any one of the preceding claims wherein the latch member comprises an abutment shoulder against which a portion of the locking member abuts when in the locking position to lock the latch member against rotation.A lift lock mechanism as claimed in any one of the preceding claims wherein the latch member comprises a substantially U-shaped receiving opening to receive the latch bolt thereinto when in the latched position.A lift lock mechanism as claimed in claim 7 wherein the substantially U-shaped receiving opening comprises a pair of jaws which are spaced apart from one another to define the substantially U-shaped receiving opening 9. A lift lock mechanism as claimed in claim 6 or claim 8 wherein in the free position, the latch member is pivoted into an upwardly angled position relative to the lock body, with the substantially U-shaped receiving opening in the latch member oriented in an upwardly angled position and the substantially U-shaped receiving opening is substantially parallel to the plane of the cover when in the latched position.A lift lock mechanism as claimed in any one of the preceding claims wherein the latch member is biased into the free position.A lift lock mechanism as claimed in any one of the preceding claims wherein the locking member is mounted within the lock body between the latch member and the threaded locking pin A lift lock mechanism as claimed in any one of the preceding claims wherein the locking member is biased into the released position.A lift lock mechanism as claimed in any one of the preceding claims wherein the locking member comprises a first L-shaped arrangement oriented toward the 10. 11. 12. 13. 14. 15. 16. 17. 18. 19.threaded locking pin and comprising an upstand part substantially parallel to the locking pin when in the released position.A lift lock mechanism as claimed in claim 13 wherein the upstand part has an abutment end provided at a free end of the upstand part to abut an enlarged head of the threaded locking pin.A lift lock mechanism as claimed in claim 14 wherein the abutment end is substantially perpendicular to the enlarged head of the threaded locking pin when in the released position and is angled relative to the enlarged head of the threaded locking pin when in the locking position.A lift lock mechanism as claimed in either one of claims 14 or 15 wherein the abutment end extends above the locking body when the lift lock mechanism is in the unlocked condition and is depressed by the enlarged head of the locking pin when the locking pin is in the locked position driving rotation of the locking body.A lift lock mechanism as claimed in any one of claims 13 to 16 further comprising a second L-shaped arrangement extending in a second direction toward the latch member.A lift lock mechanism as claimed in claim 17 wherein the second L-shaped arrangement is radially offset relative to the first L-shaped arrangement.A lift lock mechanism as claimed in either one of claims 17 or 18 wherein the second L-shaped arrangement comprises a downcomer portion angled relative to the lock body when the locking member is in the released position and substantially perpendicular to the locking body when in the locked position and a locking arm portion substantially parallel to the lock body when in the locking position and angled relative to the locking body when in the released position.20. A lift lock mechanism as claimed in claim 17 wherein the locking arm portion comprises an abutment edge or surface to abut the latch member when the locking member is in the locking position.21. A lift lock mechanism as claimed in any one of the preceding claims wherein the locking pin extends perpendicularly to the lock body and comprises an enlarged head to drive movement of the locking member when tightened.22. A lift lock mechanism as claimed in claim 21 wherein the locking pin comprises an engagement portion on upper side of the enlarged head to allow the locking pin to be driven in rotation.23. An in-ground chamber system comprising an in-ground chamber, a cover and a lift lock mechanism as claimed in any one of the preceding claims for releasably locking the cover relative to the in-ground chamber.24. An in-ground chamber system as claimed in claim 23 further comprising a cover frame associated with the in-ground chamber, to receive the cover.25. An in-ground chamber system as claimed in claim 23 or claim 24 wherein the cover comprises at least one opening through the cover to allow access to the locking pin of the lift lock mechanism.26. An in-ground chamber system as claimed in any one of claims 23 to 25 wherein a latch bolt is provided relative to an underside of the cover, substantially parallel to an upper surface of the cover.27 An in-ground chamber system as claimed in claim 26 wherein the cover further comprises a cover retention assembly on at least one side of the cover opposed to the latch bolt.28. An in-ground chamber system as claimed in claim 27 wherein the cover retention assembly includes a substantially L-shaped member with a downcomer portion and a laterally extending portion extending laterally outwardly from a centre of the cover.29. An in-ground chamber system as claimed in claim 27 wherein an opening is provided in at least one side wall of the in-ground chamber and/or the cover frame to receive at least a part of the laterally extending portion.30. An in-ground chamber system as claimed in any one of claims 23 to 29 wherein the lock body of the lift lock mechanism is mounted within the in-ground chamber relative to an abutment ledge provided on at least one side wall and/or cover frame to brace the lock body against movement.