GB2361960A - Improved strike for a bolt of a lock or a latch - Google Patents

Abstract

A box strike for a bolt (12; 13) has in its interior a laterally adjustable member (25) which provides a wall (26) having a flat abutment surface which it is intended the bolt engages when a door carrying the bolt is closed onto an associated frame in which the strike is received. The wall (26) is parallel to opposite side walls (21,22) of the strike and is slidably adjustable therebetween by loosening headed clamping screws (32,33) engaged with tabs (27,28) extending at right angles from said wall (26). Respective slots (31,31) in said tabs allow the sliding adjustment thereof relative to the shanks of the screws (32,33) respectively. Adjustment of the position of the wall (26) compensates for a change in the alignment of the bolt with the strike and can prevent rattling of the door when closed by ensuring the bolt is tightly held against the abutment surface of the wall (26).

Description

1 2361960 EMPROVED STRIKE FOR A BOLT OF A LOCK OR A LATCH This invention

relates to a strike for a latch bolt and/or dead bolt and of the form known as a box strike where a box, normally of steel, is secured, normally welded, to one side of a striking or locking plate. When the member, such as a door, carrying the latch and/or dead bolt is closed/locked, the latch and/or dead bolt extends through an opening in the striking or locking plate so as to be enclosed in the box as protection against attack with a jemmy.

An object of the invention is to provide a strike in an improved form.

According to the invention there is provided a strike for a bolt of a lock or a latch comprising a box structure having opposite side walls, upper and lower walls, a rear wall and a strike plate forming a front wall and having an opening therethrough for access into said box structure, there being within the box structure abutment means for engagement, in use, with said bolt of the latch or said bolt of the lock when received through said opening in the strike plate, the abutment means being adjustable in position laterally between said side walls.

Preferably the abutment means defines a surface for said engagement of said bolt of the latch or said bolt of the lock. Desirably the surface is parallel to said side walls, and conveniently it is slidably adjustable laterally between said side walls. Advantageously adjustment of the abutment means can be effected through said opening in the strike plate.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a front view of a strike of the invention, Figure 2 is a side view of the strike, and Figures 3 to 5 are schematic interior plan views of the strike with adjustment means thereof in three different positions respectively to engage a latch bolt.

Shown in the drawings is a door 10 and associated frame 11. Fitted at the edge of the door is a mortice lock (not shown) which has a dead bolt 12 and a latch bolt 13 of conventional form for extension out of and retraction into the lock upon key/handle operation. The part of the door frame facing the lock when the door is closed, as shown in Figures 3 to 5, is rebated and morticed, to receive a strike in the form of a striking plate 14 to the rear of which is secured an enclosure 15. This form of strike is commonly known as a box strike, box striker or box striking plate. Both the striking plate 14 and the enclosure 15 are made of metal. The striking plate 14, best shown in Figures 1 and 2, is of generally rectangular form but has a tab 16 at one of its longitudinal sides, in a conventional manner to provide a run-in for the latch bolt 13 when the door is closed with the latch bolt extended. A pair of centrally disposed, longitudinally spaced apart rectangular openings 17 and 18 are provided in the plate 14 generally alongside the extent of the tab 16, and above and below this pair of openings, i.e. at respective opposite ends of the plate, are countersunk holes 19 to receive fixing screws to secure the striking plate 14 in the aforementioned rebate in the frame 11.

Received in the above-mentioned mortice in the frame is the enclosure 15. This is in the form of an open rectangular box-like structure having a rear wall 20, with integral opposite side walls 21,22 respectively and integral upper and lower walls 23,24 respectively. As can be seen from Figure 2, the walls 23 and 24 have respective parts 23a, 24a, extended outwardly at 90'. The material and thickness of the enclosure, particularly its side walls would be such as to resist attack by a jemmy or other hnplement, such as by drilling through the frame.

As can be seen from the Figures, the enclosure 15 is received in the mortice in the frame with the striking plate 14 being received in the rebate at the exterior of the frame, so that the striking plate closes the open box-like structure of the enclosure so as to form the completed, closed box strike.

At the top and bottom of the enclosure, the outwardly extended parts 23a, 24a respectively of the upper and lower walls 23,24 are secured, for example by welding, to the rear face of the plate 14 so as to position the enclosure directly behind the area of the plate containing the openings 17 and 18, as shown in Figure 1. Moreover the free longitudinal edge surface of the right hand side wall 21 also engages the rear of the striking plate 14 and is secured thereto, again for example by welding. However the left hand side wall 22 terminates just short of the rear surface of the striking plate 14 to define a gap, as shown in Figures 2 to 5. Instead of the parts 23a,24a being welded to the rear of the plate 14, the securement could be by other means, for example by utilising the respective openings shown in these parts in phantom in Figure 1.

As will be appreciated a certain degree of skill is required in providing the relative positions of the mortice for the door lock and the mortice and rebate for the box strike. However normally a reasonably good fit of the lock can initially be achieved. However the door may warp slightly with age, or alternatively the door frame may distort, or other settling occur with the result that the alignment of the box strike with the latch or dead bolt of the lock can change. As a result the door will rattle when closed, or it will not close sufficiently for the latch bolt or dead bolt to fit the box strike. The conventional box strike could be refitted, but this requires a somewhat laborious and time-consuming operation. The present invention seeks to solve the above-mentioned problem by providing adjustment means within the box strike to ensure that the door in its closed position is always held tightly at the strike.

As can be seen from the Figures, the wall 22 is arranged with its inner surface offset at one side of the plane containing the respective left hand edges of the openings 17 and 18 in the striking plate 14, this interior surface of the wall 22 being offset in the direction of the tab 16. This is in contrast to the equivalent inner surface of a conventional box strike which would be in alignment with the respective left hand inner edges of the openings of the striking plate. Fitted within the box strike is a metallic adjustment member 25 which could, for example, be a metal pressing or stamping. The main part of the member 25 is in the form of a flat rectangular plate or strip 26 which has a length substantially corresponding to the inner longitudinal dimension of the enclosure 15 so that, as will be described, it extends from just below the inner surface of the upper wall 23 to just above the inner surface of the lower wall 24, this strip 26 lying parallel to the side walls 21 and 22.

Extending from one of its longitudinal sides, at 90' from the plane of the strip 26, are a pair of longitudinally spaced integral tabs or tongues 27,28 respectively. As can be seen from Figure 1, these tongues are positioned and spaced apart relative to the strip 26 so that they are disposed centrally of the openings 17 and 18 respectively, for a purpose to be hereinafter described. At its opposite longitudinal edge, the strip 26 is formed, along its whole length, with a short integral extension portion 29 which extends outwardly therefrom at 900 in the opposite direction from the extent of the tongues. As can be seen from Figures 3 to 5, the width of this portion 29 corresponds substantially to the gap between the end of the side wall 22 and the rear face of the striking plate 14, so that, as will be described, this portion 29 can be received in said gap. A middle tab for aligning the member 25 can be provided, this tab being shown in Figures 1 and 2 between the tabs 27 and 28. Moreover respective strengthening ribs can be provided between the tabs 27, 28 and the plate or strip 26.

As can be seen from Figure 1, each tongue has extending inwardly from its free end, i.e. its end remote from the strip 26, an elongated parallel sided slot, the slots being shown at 30 and 31 for the tongues 27,28 respectively. As also shown in Figure 1, it can be seen that parallel sides of each slot lie at 90'to the longitudinal side edges of the openings 17 and 18. The rear wall 20 of the enclosure 15 is provided with a pair of openings therethrough, these openings being spaced apart longitudinally so as to be generally at the centre both vertically and horizontally of the rectangular areas viewed through the openings 17 and 18, each opening also being disposed horizontally at the centre line of the slot in the tongue of the adjustment member. Respective fixing screws 32,33 are received through the openings, with the shank of each screw extending through an appropriate slot 30 or 31 in an associated tongue 27 or 28, with the head of each screw being oversized relative to the slot so that when the screw is fully tightened, the head engages the outwardly facing surface of the tongue around the area of the slot so as to lock the adjustment member in position. As shown in Figures 2 to 5, respective nuts 34,35 are secured on the ends of the respective shanks of the screws 32,33, and if these are non-rotatably received in appropriate respective rebates at the back of the mortice for the enclosure 15, rotation of the screws by a suitable implement inserted through the openings 17 and 18 will tighten or loosen the screws relative to the nuts thereby allowing guided adjustment of the member 25, as will be described. Alternatively the openings in the rear wall could be threaded with the respective shanks of the screws 32 and 33 being engaged with said threaded openings, so that again rotation of the screws by a suitable implement inserted through the opening 17 or 18 tightens or loosens the screws so as to release or lock the respective heads of the screws onto the tongues, thereby releasing or locking the member 25.

Referring to Figure 3, this schematically shows the adjustment member 25 adjustably fitted within the enclosure 15 so that the strip 26 thereof is spaced, by approximately lmm, from the interior surface of the side wall 22. In this position the portion 29 of the member 25 is received in the gap between the end of the wall 22 and the rear surface of the striking plate 14, the extent of the portion 29 being such that it extends slightly beyond the exterior surface of the side wall 22. A suitable part of the frame is rebated to accommodate this extension, and also, as will be explained, the extension of the portion 29 when the adjustment member 25 is in the position shown in Figure 5.

In Figure 3, the lock is fitted centrally in the door 10 and with the adjustment member in its above-described position, the strip 26 acts as an abutment surface against which the flat side face of the latch bolt 13 engages, as shown in Figure 3, when the door is in its closed position. Thus in this position the adjustment member 25 can be said to be fitted centrally in the enclosure 15. As will be appreciated from the description above, the member 25 is adjusted into this position by loosening the screws 32,33 by the insertion of a screwdriver through the openings 17 and 18 to undo the screws and allow for lateral sliding movement of the tongues about the respective shanks of the screws, the provision of the slots allowing this sliding movement to take place. When the strip 26 is correctly positioned so as to be abutted by the flat side of the latch bolt 13 as shown in Figure 3, the screws are then tightened until the heads thereon engage tightly against the tongues thereby locking the adjustment member in the correct position. This adjustment will normally be by trial and error, i.e. closing the door after each adjustment of the member 25 and seeing if it is tightly held by the engagement of the latch bolt against the strip 26.

As mentioned previously, the alignment of the lock and the box strike can vary over a period of time, and Figures 4 and 5 show how the adjustment member 25 can be repositioned as required to compensate for such changes in alignment. From the above, it will be appreciated that each time that adjustment is required, it is merely necessary to loosen the screws 32 and 33 and then slide the adjustment member 25 towards or away from the side wall 22 until the correct adjusted position is reached, whereupon the screws are retightened to lock the member 25 in place.

Figure 4 shows the lock fitted centrally in the door and the adjustment member now adjusted to be 1nun offset from its Figure 3 position forwardly in the frame, i. c. in a direction away from side wall 22. In other words in this position the adjustment compensates for the latch bolt, in the closed position of the door, being further to the right as viewed in Figures 3 and 4.

In contrast, with the arrangement shown in Figure 5, the compensation is for the latch bolt being further to the left relative to the box strike, and accordingly it can be seen that in this position the adjustment member has been moved l mm offset towards the side wall 22, i.e. backwards in the frame where it is contacted by the flat side face of the latch bolt 13 in the door closed position. In this state the strip contacts the side wall 22. By appropriate sizing of the tongues, slots and other dimensions of the box strike, it will be appreciated that various degrees of adjustment can be catered for using the principal of the invention disclosed.

Figure 3 shows the dead bolt 12 in position when the latch bolt 13 engages the strip 26. From this it can be seen that generally the dead bolt does not engage the abutment surface provided by the abutment member 25 but is disposed clear thereof, it generally being desired with mortice locks that there is no resistance to the throwing of the dead bolt by key operation, so that the dead bolt moves into the box strike without resistance. It will be understood that generally the latch bolt, being the upper bolt, will be received through the opening 17 whilst the dead bolt will be received through the opening 18.

However in an alternative arrangement the dead bolt could also engage the strip 26 when thrown, and in an alternative arrangement the box striker could be provided with only one of the openings 17 and 18 for use with a lock having a single bolt, either a latch bolt or a dead bolt, with the strip being engaged, in its adjusted position, by the appropriate bolt when extended.

It will be appreciated that the degree of adjustment with any particular construction of box strike will be governed by various factors. For example in moving the adjustment member to the left, as shown in Figure 5, it is necessary for the length of the tongue to be such that the adjustment does not cause the slot in the tongue to move clear of the shank of the screw, whilst for adjustment in the opposite direction, clearly the length of the slot must be sufficient to allow the adjustment required, and additionally there must be sufficient space within the box strike so that the free end of the tongue does not engage the inside surface of the opposite side wall towards which the adjustment is being made. It will be appreciated that means other than fixing screws could be provided to release and engage the tongues.

Claims (18)

1 A strike for a bolt of a lock or a latch comprising a box structure having opposite side walls, upper and lower walls, a rear wall and a strike plate forming a front wall and having an opening therethrough for access into said box structure, there being within the box structure abutment means for engagement, in use, with said bolt of the latch or said bolt of the lock when received through said opening in the strike plate, the abutment means bei g adjustable in position laterally between said side walls.

2. A strike as claimed in Claim 1, wherein the abutment means defines a surface for said engagement of said bolt of the latch or said bolt of the lock.

3. A strike as claimed in Claim 2, wherein the surface is parallel to said side walls.

4. A strike as claimed in Claim 2 or Claim 3, wherein said surface is defined by a wall which is slidably adjustable laterally between said side walls.

5. A strike as claimed in Claim 4, wherein a tab extending from said wall is slidably adjustably guided on a clamping member for positionally adjusting said wall.

6. A strike as claimed in Claim 5, wherein a threaded shank of said clamping member extends through a slot in said tab to allow said slidable adjustment when a head of said clamping member is disengaged from the tab, said head being engagable with said tab to clamp it in an adjusted position.

7. A strike as claimed in Claim 6, wherein said threaded shank extends through an opening in said rear wall and engages with a non-rotatable nut at the exterior of said rear wall.

8. A strike as claimed in Claim 6, wherein said threaded shank engages with a screw-threaded bore through said rear wall.

9. A strike as claimed in any one of Claims 5 to 8, wherein the clamping member is a headed screw.

10. A strike as claimed in any one of Claims 5 to 9, wherein the clamping member is accessible through said opening in the strike plate for engagement by a implement to move said clamping member into or out of engagement with said tab to prevent or allow adjustment of said wall of the adjustment means.

11. A strike as claimed in any one of Claims 5 to 10, wherein said tab extends at 901 from one longitudinal edge of said wall in one direction and a projection extends at 901 from the other longitudinal edge of said wall in the opposite direction, said projection being arranged to extend into an opening between said strike plate and one of said side walls.

12. A strike as claimed in any one of Claims 1 to 11, wherein a side wall is secured at a free end thereof to a rear face of said strike plate.

13. A strike as claimed in any one of Claims 1 to 12, wherein respective extensions of said upper and lower walls at 90' thereto are secured to a rear face of said strike plate.

14. A strike as claimed in Claim 12 or Claim 13, wherein the securement to said rear face of said strike plate is by welding.

15. A strike as claimed in any one of the preceding claims, wherein the strike plate has two longitudinally spaced apart openings therethrough providing access into said box structure for reception of said bolt of the lock and a latch respectively, in use.

16. A strike as claimed in any one of the preceding claims, wherein the abutment means is metallic.

17. A strike as claimed in Claim 16, wherein the abutment means is a pressing or stamping.

18. A strike substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.