GB2086976A

GB2086976A - Sliding bolt

Info

Publication number: GB2086976A
Application number: GB8131867A
Authority: GB
Original assignee: Ingersoll Locks Ltd
Current assignee: Ingersoll Locks Ltd
Priority date: 1980-10-23
Filing date: 1981-10-22
Publication date: 1982-05-19
Also published as: GB2086976B

Abstract

A sliding bolt 1 has a screwthread 2 engaged by spring pawls 41 so that it may be moved to its projecting position (shown) by simple axial pressure, but can only be retracted by rotation by means of a key inserted at end 7. <IMAGE>

Description

SPECIFICATION A lock This invention relates to locks.

According to the present invention there is provided a lock for securing a first member relative to a second member comprising: a casing arranged to be fixed to one of the first and second members; a bolt mounted within said casing so as to be movable between a locked position in which, in use, it engages the first member or keeper means thereon to prevent relative movement between the first member and the second member, and an unlocked position in which relative movement between the first member and the second member is permitted, said bolt having a screwthreaded portion; and ratchet means engaged with the screwthreaded portion to permit the bolt to be axially moved from the unlocked position to the locked position, the bolt being movable from the locked position to the unlocked position only by rotation thereof by means of a key.

In one embodiment said ratchet means comprises at least one spring detent finger in engagement with the screwthreaded portion of the bolt. Said spring detent finger or fingers may be integral with a member located within the casing. Said member may enclose said at least one spring detent finger. Said member may be fixed to the casing.

Alternatively said ratchet means may comprise a ratchet member pivotally mounted on a fixed structure within the casing, spring means being provided to bias the ratchet member towards the bolt.

Preferably a portion of the bolt projects outwardly of the casing in the unlocked position, said part of the bolt being enclosed by a sleeve which is rotatable relative to the bolt.

Advantageously a portion of the bolt projects outwardly of the casing in the locked position and is enclosed by a sleeve which is rotatable relative to the bolt.

Ramp surfaces may be provided on the bolt to enable the ratchet means to be disengaged from the screw threaded portion of the bolt to permit removal of the bolt from the casing.

In one embodiment a part of the bolt projects outwardly of the casing in the locked position and is enclosed by a sleeve, means being provided for preventing rotation of the sleeve relative to the casing, the bolt being rotatable relative to the sleeve. Thus the sleeve may have a non-circular external cross-section and passes through a correspondingly shaped aperture in the casing.

The invention is illustrated, merely by way of example, in the accompanying drawings, in which: Figure 1 is a sectional view of a bolt assembly of one embodiment of a lock according to the present invention; Figure 2 is a perspective view of a housing bracket of the lock of Figure 1; Figure 3 is a perspective view of one form of ratchet mechanism of a lock according to the present invention; Figure 4 is a section through one embodiment of a lock according to the present invention, and showing a key for operating the same; Figure 5 is a section through a modification of the bolt assembly of Figure 1; Figure 6 is a section through a keeper or staple for a lock according to the present invention; Figure 7 is a view of a locking plate of a lock according to the present invention;; Figure 8 is a section through another embodiment of a lock according to the present invention showing a modified ratchet mechanism; Figure 9 is a perspective view, partially broken away, of the modified ratchet mechanism of Figure 8, Figure 10 is a section through a further embodiment of a lock according to the present invention; Figure 11 is a perspective view of part of a ratchet mechanism of the lock of Figure 1 0; Figure 12 is a section taken on the line 12-12 in Figure 10; and Figure 13 is a part sectional view of a bolt assembly of the lock of Figure 1 0.

Throughout the drawings like parts have been designated by the same reference numerals.

Referring first to Figure 1, there is illustrated a bolt assembly of one embodiment of a lock according to the present invention. The bolt assembly has a bolt 1 with a circular cross section and with a two start tapered thread 2 along part of its length. The taper of the thread 2 causes a reduction in the depth of the thread towards an unthreaded forward end 1 a of the bolt. The thread 2 terminates at the forward end 1 a in an annular groove 3 and at its opposite end at an unthreaded rear end 1 b of the bolt. A retaining groove 6 is provided at the rear end 1 b which terminates with a driving spigot 8 which is dimensioned to engage with a key socket 36 of a key 35 (Figure 4). Thus rotation of the key when the spigot 8 is engaged with the key socket 36 causes the bolt to rotate.

The bolt assembly has a shouldered sleeve 9 which is disposed over the rear end 1 b of the bolt and is retained thereon by swaging a reduced diameter portion 10 of the sleeve into the groove 6 in such a way as to allow the sleeve 9 to rotate freely relative to the bolt 1. At the forward end 1 a of the bolt, ramp surfaces 11 of radiused cross section are provided and these connect with the annular groove 3.

In the assembled lock, the bolt assembly shown in Figure 1 is contained within a U-shaped housing bracket 12 (Figure 2) which is provided with a plurality of holes 13 in its upstanding legs 14, the holes 13 accommodating the forward end I a of the bolt and the sleeve 9. The housing bracket 12 is also provided with fixing holes 1 5 in its base enabling it to be fixed, for example, by screws 5 to a movable member (not shown) for example, a window.

A ratchet mechanism 1 6 (Figure 3) has two inwardly biased spring detent fingers 1 7 which are integral with a base member 1 6a and which engage with opposite sides of the thread 2 of the bolt 1. The detent figures 17 are located in a plane containing the axis of the bolt 1 with their distal ends 1 9 directed towards the forward end 1 a of the bolt. A rear end 1 8 of the ratchet mechanism 16 abuts a face 20 of one of the upstanding legs 14 of the housing bracket 1 2. The ratchet mechanism 1 6 is fixed by the base member 1 6a within a moulded plastics casing 21 (Figure 4) by a rivet 22 integral with the casing.Alternatively, the ratchet mechanism can be designed to be attached directly to the face 20 of the housing bracket 12.

The casing 21 is box-shaped and is provided with holes 23 in its end faces 24 which will align with the holes 13 in the housing bracket 12 and permit the passage of the bolt assembly through the casing 21 and the housing bracket 12 as shown in Figure 4. The casing 21 is arranged to be a snap-on fit over the housing bracket 12 by the provision of projections 25 on the casing 21 and is further retained on the casing by the bolt assembly.

In operation, the housing bracket 12 is suitably positioned on, for example, a fixed member, for example a window frame and is secured thereto by the screws 5 which pass through the fixing holes 1 5. The casing 21 and the ratchet mechanism 16 are then clipped over the housing bracket 12 with the spring detent fingers 1 7 facing forwardly, that is, in the direction of throwing of the bolt assembly. The bolt assembly is then introduced into the bracket/casing assembly and pushed through until a shoulder 7 of the sleeve 9 abuts one of the end faces 24 of the casing 21. The shoulder 7 of the sleeve 9 is such that the distal ends 1 9 of the spring detent fingers 1 7 remain in engagement with the rear portion of the thread 2.The spring detent fingers by virtue of their engagement with the thread 2 prevent the bolt assembly from being moved axially from a locked position (shown in Figure 4) to an unlocked position merely by pressure applied in the rearward direction to the forward end 1 a of the bolt 1.

To throw the bolt from the locked position shown in Figure 4 to the unlocked position, the socket 36 of the key 35 is engaged with the spigot 8 and the key rotated in order to rotate the bolt.

The distal ends 1 9 of the spring detent fingers 17 now act as a stationary nut and rotation of the bolt assembly in the appropriate direction will cause the bolt assembly to be moved from the locked position to the unlocked position under the influence of the thread 2 until the distal ends 19 of the spring detent figures 17 arrive at the annular groove 3 thus preventing further movement of the bolt assembly in a rearward direction.

It may be necessary to adjust the position of the lock on the fixed member or remove it for decorating purposes, and in order to achieve this, it is necessary to remove the bolt assembly. It is in order to facilitate this that the ramp surfaces 11 are provided. In order to remove the bolt, the bolt is rotated with the key 35 until the ramp surfaces 11 are aligned with the distal ends 19 of the spring detent fingers 1 7 so that the bolt assembly may now be pushed from the casing by pressure applied to the forward end 1 a of the bolt.

The lock illustrated in Figures 1 to 4 may be used in many security applications including the securing of wood or metal casements, sliding and sash windows, cupboards, medicine cabinets, doors and indeed any application where it is desired to secure a movable member relative to a fixed member.

In certain applications the forward end 1 a of the bolt 1 may be accessible and so the bolt assembly could be rotated without the key 35. To avoid this a sleeve 26 (Figure 5), which can be rotated independently of the bolt 1 , to perform a similar function to the sleeve 9, can be provided to make it difficult or impossible to rotate the bolt assembly via its forward end 1 a.

A lock according to the present invention may also be used in conjunction with the keeper or box staple shown in Figure 6, the box staple comprising a U-shaped bracket 27 which is provided with a bolt aperture 29 at one end and a fixing screw hole 28 in a base. The base is also provided with barbs 30 to prevent movement of the staple after it has been fixed to a fixed member such as a window frame. A moulded plastics casing 31 fits over the bracket 27 and is retained thereon by a projection 32. The casing 31 also has a bolt receiving aperture 33 which aligns with the bolt aperture 29 in the bracket 27.

Alternatively, a lock according to the present invention may be used in conjunction with a locking plate 34 (Figure 7) which is arranged with a bolt receiving aperture 37 and fixing screw holes 38 for fixing the locking plate to a fixed member, such as, a window frame.

Figures 8 and 9 illustrate another embodiment of a lock according to the present invention having a modified ratchet mechanism 39 comprising a sheet metal open box-shaped housing 40 with spring detent fingers 41 each formed integrally with a side wall 42 of the housing 40. The spring detent figures operate in the same manner as the spring detent fingers 17 of Figure 3. The advantage of this ratchet mechanism is that, in the assembled lock, if an unauthorised attempt is made to remove the casing 21 , for example, by heating, the spring detent fingers 41 still remain inaccessible, because they are located within the housing 40 whose open side faces the base ofthe housing bracket 12, until the bolt assembly is removed. The housing 40 is not fixed to the casing 21 but is located by the bolt assembly which, in the assembled lock, passes through apertures 44 in the housing 40, the apertures 44 being aligned with the holes 1 3 in the housing bracket 12 and the hole 23 in the casing 21.

Figures 10, 11 and 12 illustrate another embodiment of a lock according to the present invention. The lock of Figure 4 has the disadvantage that if an excessive force is applied to the forward end 1 a of the bolt 1 in an attempt to move the bolt assembly from the locked position to the unlocked position without rotating the bolt, the spring detent fingers may be deformed to permit such movement. The lock shown in Figure 10 overcomes this problem by providing a ratchet mechanism 49 which comprises a pair of T-shaped members 50 which are mounted for pivotal movement on an opensided metallic box-shaped housing 51 (best seen in Figure 11). Each member 50 passes through a Respective aperture 52 in the housing 51 and a leg 53 thereof is engaged by a spring member 54 integral with a side wall 55 of the housing.The distal end of each spring member 54 has a pair of locating lugs 56 between which the distal end of the leg 53 of the respective member 50 is located, and a tongue 57 which bears against the leg. Thus the spring members 54 bias the legs 53 of the member 50 towards the bolt assembly. If an excessive force is applied to the forward end 1 a of the bolt 1 in an attempt to move the bolt assembly from the locked position to the unlocked position, this force is transmitted by the members 50 to the housing bracket 12 and since the members 50 may be made relatively massive, these are less likely to deform than the spring detent fingers 1 7 of the lock of Figure 4. No force is transmitted to deform the spring members 54.

To prevent the bolt assembly from being rotated and moved from the locked position to the unlocked position by rotation of the part of the bolt 1 extending outwardly of the casing 21, a sleeve 60 having a non-circular external crosssection is provided on the forward end 1 a of the bolt 1. The hole 13 in the housing and the hole 23 in the casing adjacent the sleeve 60 have substantially the same shape as the cross-section of the sleeve 60 to prevent rotation. As shown in Figure 10 the sleeve 60 has a rib 61 to create a non-circular cross-section, but it will be appreciated that the external cross-section of the sleeve could be square, oval etc.

As shown in Figure 13 the sleeve 60 has an internal groove 63 and a pin 64, having a length which is greater than the diameter of the forward end 1 a of the bolt is located in the groove 63. The pin 64 is inserted through the bolt into the groove 63 via apertures 65. Thus the bolt 1 can be rotated relative the sleeve 60 which itself cannot rotate and so the bolt assembly can be moved from the locked position to the unlocked position by means of a key. The sleeve 60 can be removed by removing the pin 64 so allowing the bolt assembly to be withdrawn and the lock disassembled.

Claims

1. A lock for securing a first member relative to a second member comprising: a casing arranged to be fixed to one of the first and second members; a bolt mounted within said casing so as to be movable between a locked position in which, in use, it engages the first member or keeper means thereon to prevent relative movement between the first member and the second member, and an unlocked position in which relative movement between the first member and the second member is permitted, said bolt having a screwthreaded portion; and ratchet means engaged with the screw-threaded portion to permit the bolt to be axially moved from the unlocked position to the locked position, the bolt being movable from the locked position to the unlocked position only by rotation thereof by means of a key.

2. A lock as claimed in claim 1 in which said ratchet means comprises at least one spring detent finger in engagement with the screwthreaded portion of the bolt.

3. A lock as claimed in claim 2 in which said spring detent finger or fingers are integral with a member located within the casing.

4. A lock as claimed in claim 3 in which said member encloses said at least one spring detent finger.

5. A lock as claimed in claim 3 or 4 in which said member is fixed to the casing.

6. A lock as claimed in claim 1 in which said ratchet means comprises a ratchet member pivotally mounted on a fixed structure within the casing, spring means being provided to bias the ratchet member towards the bolt.

7. A lock as claimed in any preceding claim in which a part of the bolt projects outwardly of the casing in the unlocked position, said part of the bolt being enclosed by a sleeve which is rotatable relative to the bolt.

8. A lock as claimed in any preceding claim in which a part of the bolt projects outwardly of the casing in the locked position and is enclosed by a sleeve which is rotatable relative to the bolt.

9. A lock as claimed in any preceding claim in which ramp surfaces are provided on the bolt to enable the ratchet means to be disengaged from the screw threaded portion of the bolt to permit removal of the bolt from the casing.

10. A lock as claimed in any of claims 1 to 4 in which a part of the bolt projects outwardly of the casing in the locked position and is enclosed by a sleeve, means being provided for preventing rotation of the sleeve relative to the casing, the bolt being rotatable relative to the sleeve.

11. A lock as claimed in claim 10 in which the sleeve has a non-circular external cross-section and passes through a correspondingly shaped aperture in the casing.

12. A lock substantially as herein described with reference to and as shown in the accompanying drawings.