GB2210656A

GB2210656A - A lock

Info

Publication number: GB2210656A
Application number: GB8723628A
Authority: GB
Inventors: Gary Barrs
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-10-08
Filing date: 1987-10-08
Publication date: 1989-06-14
Anticipated expiration: 2007-10-08
Also published as: GB2210656B; GB8723628D0

Abstract

A lock comprises a housing 1, a bolt work 11 consisting of a plate within the housing and a separate bolt 22 mounted on the plate. The bolt extends through an aperture in the housing. The key moves the bolt between the first position in which the bolt projects from the housing and a second position in which the bolt is retracted into the housing. The bolt is not formed integrally with the plate within the housing which drives the bolt, and the bolt is preferably cylindrical and retained in a bore in the plate. Two bolts may be mounted in the plate and the plate may have a line of relative mechanical weakness between the two bolts. <IMAGE>

Description

Description of Invention "Improvements in or relating to a lock THE PRESENT INVENTION relates to a lock.

One type of conventional mortice lock has a single, square or rectangular sectioned bolt which is operated by a key arrangement. When the lock is in the locked condition, a portion of the bolt is thrown out of a casing of the lock. A problem arises when, as in most locks of this type, a greater portion of the bolt is thrown out of the casing than is retained within the casing. This renders the lock insecure and vulnerable as the bolt has passed the optimum working condition wherein as much of the bolt is retained within the casing of the lock as is located outside the casing.

Also, in many conventional designs, the portion of the bolt retained in the casing is of less thickness than the part of the bolt that is thrown out of the casing.

This part of the bolt is prone to break if an attempt is made to force the lock. Another problem that may arise, is that the square or rectangular bolt often does not fit perfectly within the aperture provided for it in a side wall of the lock housing and, in order to overcome this, an extra cover plate is added over the face of the bolt in order to secure the bolt againt undue lateral movement.

The present invention seeks to provide a lock in which the above described disadvantages are obviated or reduced.

According to the present invention, there is provided a lock, said lock comprising a housing; a bolt work comprising a first plate-like member located within the housing and at least one separate bolt mounted on the plate-like member and extending through an aperture in the housing; and key operated means for moving the bolt work between a first position in which said at least one bolt is projecting from the housing, and a second position in which the bolt is substantially retracted into the housing.

Preferably there are two of said separate bolts, each passing through a respective aperture in the housing. The or.each bolt may be substantially cylindrical and may be mounted on the plate-like member by having one end thereof retained in a bore in said platelike member.

Conveniently the or each bolt is retained in its bore by means of a pin passing through a cross bore in the plate-like member and a transverse bore in the bolt and the length of the or each bolt within the bore is substantially equal to the length of the bolt projecting beyond te bore.

Advantageously the said plate-like member has a line of relative mechanical weakness which divides the plate-like member into two parts, there being one bolt mounted on each part.

According to another aspect of the present invention there is provided a lock, said lock comprising a housing a bolt work located within the housing and having two bolts each extending through a respective aperture in the housing, and key operated means for moving the bolt work between a first position in which said bolts project from the housing and a second position in which the bolts are substantially retracted into the housing.

Preferably said bolt work comprises a plate-like member provided with said two bolts, said plate-like member having a line of relative mechanical weakness which divides the plate-like member into two parts, there being one bolt mounted on each part.

Advantageously the end of the or each bolt remote from the housing tapers to point.

Conveniently the bolt work is provided with an upstanding pin engaged in a substantially U-shaped slot formed in a co-operating lever, said key operated means comprising a key actuated cylinder having a projection engageable with the plate-like member to move the member from said first position to said second position, and engageable with a cam face on said lever to move the lever to such a position that the pin can move within said slot as the plate-like member is moved from the first position to the second position. The pin may be formed of hardened metal and has one end located in a bore formed in the plate-like member, with the other end projecting into said slot.

Preferably said housing comprises a casing comprising a base having peripheral upstanding flanges defining side walls of the housing, and a removable cover, the casing being cast or machined from a single integral piece of metal.

Advantageously the present invention provides a lock as described above in combination with a striking plate, said striking plate comprising a plate-like element having a front face with an aperture therein to receive the or each bolt, the or each aperture forming the mouth of a bore passing into a corresponding projection formed on the rear face of the striking plate.

The present invention also provides a method of assembling a lock, said method comprising the steps of locating, within a housing, a plate-like member to form part of a bolt-work, passing, through at least one aperture in the housing, at least one bolt and engaging the bolt with the plate-like member; and providing key operated means adapted to move the bolt work between a first position in which said at least one bolt is projecting from the housing and a second position in which the bolt is substantially retracted into the housing.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: FIGURE 1 is an exploded perspective view of a lock in accordance with the invention in a locked condition; FIGURE 2 is a cylinder for use in connection with the lock of Figure 1; FIGURE 3 is a perspective view of the lock of Figure 1 in an unlocked condition; FIGURE 4 is a rear view of a striking plate for use in connection with the lock of Figures 1 and 3; and FIGURE 5 is a plan view of the lock of Figures 1 and 3.

Referring initially to Figure 1 of the accompanying drawings, a lock, in accordance with the present invention, comprises a housing 1 having a substantially square planer base 2 and upstanding peripheral flanges 3 formed as an integral one-piece metal component using a casting or machining technique. One peripheral.flange 3a extends, at each end, beyond the adjacent sides of the base 2. The said one flange 3a is provided in the region between the two adjacent sides of the base 2 with two symmetrically positoned apertures 4 (see Figure 5) located on a line parallel with the plane of the base.

Two further apertures 5 are provided, one in each portion of the flange which extends beyond the adjacent sides of the base 2, these further apertures also being symmetrically positioned on said line parallel with the plane of the base.

The base 2 is provided with two projecting bosses 6 and 7 and a securing pin 8 which extend into the space defined by the base and the said upstanding flanges.

The first projecting boss 6 is located adjacent the midpoint of the said extended flange 3a, between the spaced apertures 4 and the second boss 7 is located in the lower opposite corner of the base 2. The two bosses are provided with axial threaded bores 9 extending from the upper ends thereof. The securing pin 8 is located in the upper opposite corner of the base from the first projecting boss 6. Furthermore, an aperture 10 is provided in the base 2 for receiving one end of a keyoperated cylinder arrangement 34 which is, in turn, provided with an actuating member 39 rotatable with the cylinder.

A bolt work in the form of a plate-like member 11 is provided within the casing 1. The plate-like member has a first substantially straight edge 12 positioned adjacent the said extended flange 3a. The straight edge has a recess 13 located at its mid-point. With the bolt work 11 positioned adjacent the extended flange, the recess 13 receives the first projecting boss 6. The plate-like member has a substantially square shaped upper region 14, a remote lower corner of which has a depending lug 15, positioned adjacent an arcuate recess 16 which is open towards the bottom of the plate-like member. A lower region 17 of the boltwork is of substantially rectangular configuration, the side thereof opposed to said straight edge merging with the arcuate recesses.The narrowest part of the plate-like member extends from the arcuate recess 16 in the upper region 14, to the recess 13 at the mid-point of the straight edge 12 thus defining a "waist" 17a which comprises a region of mechanical weakness in the bolt work between the upper and lower regions thereof.

The plate-like member 11 is provided with two blind bores 18 (see Figure 5) equally spaced on either side of the recess 13 in the said straight edge and having similar diameters and spacing as the apertures 4 in the extended flange 3a. Small diameter cross-bores 19 are provided through the plate-like member adjacent the said straight edge 12 which extend through the said blind bores 18 and are adapted to receive retaining pins 20 of an appropriate size.

An upstanding pin 21 is provided on the upper region 14 of the bolt work in close proximity to the depending lug 15. The upstanding pin 21 extends through the thickness of the plate-like member 11 and extends above the surface of the plate-like member by a distance substantially equal to the thickness thereof and is formed of an appropriate hardened metal.

Two cylindrical, machined bolts 22 are provided having slightly smaller diameters than the apertures 4 formed in the extended flange and said blind bores 18.

Each bolt is provided with a bore (not shown) located close to one end thereof which is of the same size as the cross-bores 19 provided in the bolt work. The other end of each bolt has a tapering point. The cylindrical bolts 22 are received within the blind bores 18 and are retained by pins 20 passing through the cross-bores 19 and the corresponding bores in the bolts. The length of each bolt received in the respective blind bore is substantially equal to length of the bolt that projects from the bore. This provides the lock with optimum strength.

A spring 23 is connected between the securing pin 8 provided on the base 2 of the housing and a substantially rectangular lever 24, in the form of a second plate-like member, received within the housing of the lock, and partly superimposed on the bolt work. The lower edge of the lever is provided with an arcuate concave profile 25 forming part of a downwardly extending projection on the side remote from the bolt work. A U-shaped slot 26 is formed through the lever and is dimensioned to receive the upstanding pin 21 provided on the bolt work in either of the arms of the slot, or in the base of the slot. The upstanding pin is engaged in the U-shaped slot.

A cover plate 27 is provided for the lock being of similar shape and size to the base 2. The cover plate is provided with apertures 28 at positions corresponding to the positions of the projecting bosses 6 and 7 provided on the base and an aperture 29 corresponding to the aperture 10 on the base which is intended to receive the cylinder arrangement. Threaded screws 30 extend through the apertures 28 in the cover plate 27 and into the projecting bosses 6 and 7 in order to secure the cover plate to the base of the lock.

A rectangular striking plate 31 is provided having a shape similar to that of the extended flange with apertures 32, 32a corresponding in size and spacing to the apertures provided in the extended flange. On the rear of the striking plate (see Figure 4) cylindrical bosses 33 project from the larger diameter centrally located apertures 32.

The key actuated cylinder arrangement shown in Figure 2 comprises an elongate housing 34 having a crosssection with a substantially circular upper portion 35 and a depending rectangular lower portion 36. Located at each end of the housing there is an integrally formed shoulder 37, so that each end of the housing comprises a projection of the same shape as, but slightly smaller than, the rest of the housing.

The circular cross-section part 35 of the housing contains a rotatable cyliner defining a key slot 38 at each end thereof. The cylinder is connected to a projection 39 which extends radially from the cylinder at its mid-point. The projection extends through a slot provided in the housing, and moves from one position relative to the housing, to another position, as indicated by the arrow in Figure 2, when the cylinder is actuated by the correct key.

When assembling the lock, the plate-like member 11 of the bolt work is inserted into the casing 1 of the lock and is positioned adjacent the extended flange 3a in order that the first projecting boss 6 is received within the recess 13 in the straight edge 12 of the plate-like member and the blind bores 18 of the bolt work are aligned with the corresponding apertures 4 provided in the extended flange. The cylindrical bolts 22 are then inserted, through the apertures 4 in the extended flange and into the blind bores 18 provided in the plate-like member 11. The retaining pins 20 are inserted into the cross-bores 19 provided in the bolt work and the corresponding bores provided in the bolts.

It is not necessary to tilt the bolts 22 as they pass through the apertures 4, and thus the apertures may have -substantially the same diameters as the diameters of the bolts. Thus there is no "play" in the bolts, and no supplementary cover plate is required which touches the bolts.

The lever 24 is inserted into the casing of the lock and overlies the bolt work in such a way that the upstanding pin 21 provided on the bolt work is positioned within one of the arms of the U-shaped slot 26 provided through the lever 24. The spring 23 is connected between the lever and the securing pin 8 provided on the base 2 of the lock, to bias the lever downwardly, or, in other words, to bias the lever so that the pin cannot be disengaged from the arm of the Ushaped channel in which it is located.

The cylinder has one shouldered end 37 inserted into the aperture 10 in the base with the lock components in such a condition that the actuating member 39 of the cylinder is positioned within the space defined by the base and the upstanding peripheral flanges 3 in alignment with the bolt work and the lever. The cover plate 27 is then placed onto the casing in such a way that the apertures 28 in the cover plate are aligned with the projecting bosses 6 and 7 provided on the base of the casing and the other shouldered end of the cylinder 34 is engaged with the appropriate aperture in the cover plate. The threaded screws 30 are then inserted through the apertures 28 in the cover plate and are received within the threaded bores 9 of the projecting bosses, to secure the 'cover plate to the base of the lock and retain the cylinder in position.

When the lock is to be fitted to a door, it is of great importance that the striking plate 31 is mounted on the door frame at the correct position in order that the apertures 32 therein are aligned with the axes of the bolts 22. The lock is fitted in one edge of a door in the normal mannner, and is retained in the door by screws inserted in the apertures 35. With the lock in an unlocked condition, the door is closed and the lock is actuated several times in order that the bolts 22 are gently advanced towards a locked position.When this has been repeated several times, it will be noted that the pointed ends of the bolts 22 will have marked the door frame Two holes are then drilled into the door frame at the positions indicated by the impressions left on the door frame by the bolts 22 the diameter of each of these holes being slightly greater than the diameter of one of the bosses on the rear of the striking plate. The striking plate 31 is then mounted on the door frame, within a chiselled rebate if necessary, with the cylindrical bosses 33 extending into the holes drilled in the door frame. The striking plate 31 is secured in position by inserting threaded screws through bores provided on the striking plate and into the door frame.

In this way the apertures 32 in the striking plate are exactly aligned with the bolts 22 of the lock.

In use of the lock, starting from a locked position, as shown in Figures 1 and 5, a key is inserted into the cylinder arrangement and is turned in a clockwise direction within the cylinder 35. This, in turn, rotates the actuating member 39 carried by the cylinder arrangement in a clockwise direction. The actuating member 39 contacts the arcuate profile 25 provided on the lower edge of the lever 24 and, due to the precise shape of the profile, the lever is raised by the actuating member against the spring bias provided by the spring 23. As the lever is raised, the upstanding pin 21 provided on the bolt work effectively moves down one arm of the U-shaped slot 26 formed in the member and becomes aligned with the base of the slot.As the actuating member 39 continues on its path around the cylinder 35, it also engages an edge of the depending lug 15 adjacent the arcuate recess 16 provided on the bolt work and retracts the bolt work complete with the bolts 22 into the space defined within the casing by the base and the upstanding flanges 3 until the upstanding pin 21 provided on the bolt work has travelled to the base of the second arm of the U-shaped slot 26.

The actuating member 39 continues its path along the arcuate profile 25 on the lower edge of the lever 24 and, when the actuating member has completed its rotation around the cylinder 35, the lever 24 is returned, by way of the spring 23, to its original position. However, the upstanding pin 21 provided on the bolt work is held in the second arm of the U-shaped slot 26and the bolt work and bolts are withdrawn into the casing 1 of the lock. Thus the lock is now held in an unlocked condition.

To return the lock to a locked condition, the key is turned within the cylinder 35 in an anti-clockwise direction. This, in turn, rotates the actuating member 39 provided on the cylinder in an anti-clockwise direction. The actuating member 39 rotates around the cylinder and contacts the arcuate profile 25 provided on the lower edge of the lever 24. Thus, the lever is raised and the upstanding pin 21 provided on the bolt work is freed from the second arm of the U-shaped slot 26 and is again aligned with the base of the slot. As the actuating member 39 continues to rotate, it engages an edge of the depending lug 15 remote from the arcuate recess 16 in the bolt work and advances the bolt work, and subsequently, the bolts 22, towards the extended flange 3a in order that the bolts extend through the apertures 4 in the extended flange.When the actuating member 39 has rotated to such a position that it no longer contacts the arcuate profile 25 on the lower edge of the lever, the lever 24 is returned to its original position, thus trapping the upstanding pin 21 within the first arm of the U-shaped slot 26 and the lock is once mo-re in a locked condition.

It is believed that should someone attempt to force open the lock as described above, for example if pressure were to be applied to the lower most bolt in an effort to force the lock, the pressure applied to the bolt would be focussed on the waist of the bolt work (between the recess 13 in the straight edge adjacent the extended flange and the extreme upper corner of the lower region 17 of the bolt work) which would break within the lock. However, if the bolt work were to break along the waist thereof, and the lowermost bolt were to recede within the casing of the lock, the uppermost bolt would still be held firmly in a locked position as the upstanding pin 21 provided on the bolt work would still be held firmly within the first arm of the U-shaped slot 26 provided in the upper face of the lever 24, thus preventing rearward movement of the upper most bolt.

Claims

1. A lock, said lock comprising a housing; a bolt work comprising a first plate-like member located within the housing and at least one separate bolt mounted on the plate-like member and extending through an aperture in the housing; and key operated means for moving the bolt work between a first position in which said at least one bolt is projecting from the housing, and a second position in which the bolt is substantially retracted into the housing.

2. A lock according to claim 1, wherein there are two of said separate bolts, each passing through a respective aperture in the housing.

A lock according to claim 1 or 2, wherein the or each bolt is substantially cylindrical.

4. A lock according to any one of the preceding claims, wherein the or each bolt is mounted on the plate-like member by having one end thereof retained in a bore in said plate-like member.

5. A lock according to claim 4, wherein the or each bolt is retained in its bore by means of a pin passing through a cross bore in the plate-like member and a transverse bar in the bolt.

6. A lock according to claim 4 or claim 5, wherein the length of the or each bolt within the bore is substantially equal to the length of the bolt projecting beyond the bore.

7. A lock according to claim 2 or any claim dependent thereon, wherein said plate-like member has a line of relative mechanical weakness which divides the plate like member into two parts, there being one bolt mounted on each part.

8. A lock, said lock comprising a housing a bolt work located within the housing and having two bolts each extending through a respective aperture in the housing, and key operated means for moving the bolt work between a first position in which said bolts project from the housing and a second position in which the bolts are substantially retracted into the housing.

9. A lock according to claim 8, wherein said bolt work comprises a plate-like member provided with said two bolts, said plate-like member having a line of relative mechanical weakness which divides the platelike member into two parts, there being one bolt mounted on each part.

10. A lock according to any one of the preceding claims, wherein the end of the or each bolt remote from the housing tapers to a point.

11. A lock according to any one of the preceding claims, wherein the bolt work is provided with an upstanding pin engaged in a substantially U-shaped slot formed in a co-operating lever, said key operated means comprising a key actuated cylinder having a projection engageable with the plate-like member to move the member from said first position to said second position, and engageable with a cam face on said lever to move the lever to such a position that the pin can move within said slot as the plate-like member is moved from the first position to the second position.

12. A lock according to claim 11, wherein the pin is formed of hardened metal and has one end located in a bore formed in the plate-like member, with the other end projecting into said slot.

13. A lock according to any one of the preceding claims, wherein said housing comprises a casing comprising a base having peripheral upstanding flanges defining side walls of the housing, and a removable cover, the casing being cast or machined from a single integral piece of metal.

14. A lock according to any one of the preceding claims in combination with a striking plate, said striking plate comprising a plate-like element having a front face with an aperture therein to receive the or each bolt, the or each aperture forming the mouth of a bore passing into a corresponding projection formed on the rear face of the striking plate.

15. A method of assembling a lock, said method comprising the steps of locating, within a housing, a plate-like member to form part of a bolt-work, passing, through at least one aperture in the housing, at least one bolt and engaging the bolt with the plate-like member; and providing key operated means adopted to move the bolt work between a first position in which said at least one bolt is projecting from the housing and a second position in which the bolt is substantially retracted into the housing.

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

17. A method of assembling a lock substantially as herein described with reference to the accompanying drawings.

18. Any novel feature or combination of features disclosed herein.