GB2172645A - Lock - Google Patents

Abstract

The lock is provided with a plurality of sets of identical bores 103, 104, 105, 106 in front and rear sections along the length of the cylinder body, the front bore section having one set of balls or tumblers 102 and the rear section having the remainder of the bore sets each bore having a tumbler associated therewith and a cylinder barrel provided with a row of bores 201, 202 and tumblers divided into front and rear tumbler sets alignable with the front and rear bore sections in the cylinder body, a semi-circular plate 108 received in matching transverse slots 107, 203 in the cylinder body and barrel which serves to prevent the lock operating in the event of use of an unauthorised key. <IMAGE>

Description

SPECIFICATION Lock The present invention relates to a lock and is concerned particularly with a cylinder lock.

When a lock is in position on a door, two connecting screws normally secure a backplate to the door. The same connecting screws secure the cylinder lock to the front of the door. Should the cylinder lock be damaged for example by a heavy tool used on the outside of the door, then the two connecting screws tend to separate or break. Should the screws break then the lock can be removed and taken away.

According to the present invention there is provided a cylinder lock in which the cylinder body is provided with a plurality of sets of identical bores arranged in front and rear sections along the length of the cylinder body, the front bore section having one set of balls or tumblers and the rear section having the remainder of the bore sets each bore having a tumbler associated therewith and a cylinder barrel provided with a row of bore and tumblers divided into front and rear tumbler sets, alignable with the front and rear bore sections in the cylinder body, a semi-circular plate received in matching transverse slots in the cylinder body and barrel which serves to prevent the lock operating in the event of the use of an unauthorised key.

The invention will now be described further by way of example with reference to the accompanying drawings in which: Figure 1 is an exploded perspective view of a cylinder lock embodying the present invention, Figure 2 is an exploded perspective view of a sleeve for use with the lock shown in Fig.

1, and Figure 3 is an exploded view of disk combination apparatus of the present invention.

Fig. 1 shows a cylinder 2 for insertion in an axial bore 101 formed along the central axis of a cylinder body 1 on the upper side of the body 1 above the bore 101, as viewed, there are provided four sets of bores 103, 104, 105 and 106 each leading into the axial bore 101. A tumbler 102 is slidably received in each bore and loaded resiliently radially inwardly of the cylinder body 1 by a spring.

The barrel 2 has front and rear sets of bores 201, 202 each which slidably receives a tumbler. When the barrel 2 is inserted into the bore 101 the front bore set 103 is in spacial alignment with a set of bores 201 in the barrel 2 and the rear bores 104, 105 and 106 are in spacial alignment with the rear set of bores 202 in the barrel 2. The sets of bores 104, 105 and 106 are of the same diameter as the set of bores 103 with which they are arranged in parallel.

A transverse slot 107 is provided in the middle of the cylinder body 1, with which, when assembled, a corresponding slot 203 in the barrel 2 aligns. A semi-circular plate 108 is received in the slots to hold the body and barrel axially together. At the rear end of the body 1 internally threaded tubes 110 provide a fixing connection for the lock.

The lock so described operates as follows: A key 205 is inserted into the slotted aperture at the front end of the cylinder barrel and turned clockwise or anti-clockwise to align the set of bores 202 with set of bores 105 or 106.

The sets of bores 104, 105 and 106 in the cylinder body 1 are the same size, so that the tumblers received in the set of bores 202 can pass through into the bore 105 or 106. The stop plate 108 can pass through the slot in the key to enable the lock to open smoothly.

Should a thief for example, insert a skeleton key to open the tumblers in bore 103 and 104 and to rotate the cylinder barrel 2, then when the cylinder barrel 2 rotates to bore set 105 or 106 the tumblers in the sets are resiliently loaded into ball slot 202. Thus, the cylinder barrel is blocked against further rotation.

Should the thief open ball sets 105 or 106 again, the lock will not be open owing to its being blocked by the plate 108.

Referring now to Fig. 2, the flange 3.1 at one end of a sleeve 3 seats the cylinder barrel 2 on the outside of a door. The other end of the sleeve 3 is externally threaded to receive an internally threaded ring 3.3. In addition to securement by the threaded ring 3.3, auxiliary securing bolts are provided which pass through an end cap into the internally threaded tubes 100, 110. Therefore, if lock is damaged or picked by a heavy tool from outside, the lock of the present invention will be resistant to damage and the door will not open unless a very large external force is used which is sufficient to damage the securing bolts and the sleeve 3.

The disk combination shown in Fig. 3 is made in three parts, an operating knob 4, a facing cap 5 and a plate 6. The operating knob includes a cylinder having an aperture into whih a spring 402 is received to load a ball 403 radially outrwards. At the end of the cylinder adjacent the knob 4 a projection 404 is provided which is engageable into a notch 503 in an end face of the cap 5.

The cap 5 has a pair of spaced annular ball receiving grooves 501, 502 within which the plate 6 is freely received. A slot 405 internally of the cylinder receives the plate 6 as a sliding fit.

The disk combination is positioned on a door and can optionally control the door lock.

The projection 404 of the operating knob 4 is matched to the notch 503 in the bore cap 5.

If the operating knob 4 passes to the rearmost groove 502 from the front groove 501, the operating knob meshes with cap 5 so that the knob cannot be rotated from inside or outside.

Claims (4)

1. A cylinder lock in which the cylinder body is provided with a plurality of sets of identical bores arranged in front and rear sections along the length of the cylinder body, the front bore section having one set of balls or tumblers and the rear section having the remainder of the bore sets each bore having a tumbler associated therewith and a cylinder barrel provided with a row of bores and tumblers divided into the front and rear tumbler sets alignable with the front and rear bore sections in the cylinder body, a semi-circular plate received in matching transverse slots in the cylinder body and barrel which serves to prevent the lock operating in the event of use of an unauthorised key.

2. A cylinder lock as claimed in claim 1 which is mounted in a cylindrical sleeve part of the wall of which is removed, the lock having a flange which abuts against one end of the sleeve the other end of which is externally threaded to enable the sleeve to be secured to the inside surface of a door.

3. A cylinder lock substantially as herein described with reference to and as illustrated in Fig. 1 or Figs. 1 and 2 of the accompanying drawings.

4. A disk combination for use with the cylinder lock of Fig. 1 and substantially as herein described with reference to and as illustrated in Fig. 3 of the accompanying drawings.