GB2578865A

GB2578865A - Improvements in or relating to security

Info

Publication number: GB2578865A
Application number: GB1816075.4A
Authority: GB
Inventors: Inkster David
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-10-01
Filing date: 2018-10-01
Publication date: 2020-06-03
Anticipated expiration: 2038-10-01
Also published as: GB2578865B

Abstract

A cylinder lock includes a blocking insert 2 bridging the keyway which limits the depth a key can be inserted unless the key has a matching notch K1. The blocking member is T-shaped with a portion 2a extending transverse the keyway and a stem 2b extending in a longitudinal slot. The transverse section of the blocking insert may be segment shaped and of plastics or resilient material. The blocking portion and stem are preferably integrally formed by moulding. Preferably the blocking member is of interference/friction fit and may be retained in place by a circlip inserted in groove 1e.

Description

IMPROVEMENTS IN OR RELATING TO SECURITY

This invention relates to improvements in or relating to security and is more particularly concerned with key operated cylinder locks.

The Applicant is concerned with the level of security offered in cylinder locks and has addressed some of these issues in their previous UK Patent Specification No.GB2495714A. In particular, one embodiment of cylinder lock shown in Specification No. GB2495714A has a plug rotatable in a lock body, said plug have a slideway for receiving a key of matching configuration and a blocking member preventing a key of matching configuration to the slideway being slidden in the * * * *** * * * * * * slideway a sufficient extent to open the lock on rotation of the key, unless the key has * * a notch or recess co-operable with the blocking member. The blocking member **** * * **** bridges an end of the slideway such that, in use, as the key is introduced into the * slideway, the blocking member overlaps an edge of said matching key opposed to an * * ** * * * edge of the key having permutation lock recesses (formed by teeth or bits). *** 0 * * *

Moreover, the Applicant believes that said previous embodiment described in the immediately preceding paragraph has certain disadvantages or can be improved in at least some respect. These disadvantages/improvements relate to strength, durability, ease of manufacture, assembly of the components and resistance to opening the lock by the known technique of lock 'bumping'. *

Accordingly, it is an object of the present invention to provide a cylinder lock having a plug which is improved in at least some respect or in which disadvantages of some previous designs are at least alleviated. * * * * * * * ** * *

0* * * * ** * * * * * * 0 * * * * * * * * * * * * * According to the present invention there is provided a cylinder lock comprising a plug rotatable in a lock body to open the lock, the plug having a slideway for receiving a key of matching configuration to the slideway, a blocking member preventing said matching key being slidden axially in the slideway a sufficient extent to open the lock on rotation of the key with the plug, unless said matching key is provided with a notched or recessed formation co-operable with the blocking member, the blocking member being T-shaped and having a cross member portion received, in use, in a transverse slot in the plug, and having a stem portion received, in use, in a longitudinal slot in the plug, the blocking member bridging an end of the slideway such that, in use, the blocking member overlaps an edge of said matching key opposed to a key edge having permutation lock recesses or teeth..

Further according to the present invention there is provided the combination of the lock as described in the immediately preceding paragraph and a matching key provided with a notched or recessed formation co-operable with the blocking member.

Further according to the present invention there is provided a plug and blocking member for the lock as described in the penultimate paragraph.

It is believed that the T-shaped blocking member offers greater resistance to breakage because of the shape when seated in the transverse and longitudinal slots. * * * * * * * * * * * *

** * * * * **** * * * ** * * * * ** * Additionally, and most importantly, in a preferred embodiment of the cylinder lock, the blocking member is secured in place in the slots by securing or locking means (such as a circlip) to alleviate or prevent the blocking member being manipulated or lifted out of place e.g. by picking tools in order to open the lock.

Where a circlip is employed as aforementioned, this may be also retain the plug within the lock body.

In one embodiment, the circlip (or other securing or locking means) may seat in a groove in the plug and overlap said stem portion of the blocking member thereby holding said stem portion in said longitudinal slot.

Preferably, the cross member portion is of segment shape and fits snugly into the transverse slot which is of matching configuration.

Preferably, the stem portion is of rectangular configuration and fits snugly into the longitudinal slot.

Advantageously, the rectangular stem portion extends centrally at right angles to the segment shaped cross member portion from or adjacent to a straight edge portion of said cross member portion and is, preferably, of greater thickness ( usually about double the thickness) than the thickness of cross member portion in order to provide greater strength for the blocking member than would be the case if the blocking member comprised the cross member portion only, as in the known arrangement of the Applicant described in UK Patent Specification No. GB 2495714A.

Preferably, the transverse dimension of the rectangular stem portion is about half the transverse dimension of the segment shaped cross member portion.

Preferably, the height of the rectangular stem portion is about half the height of the segment shaped cross member portion.

The length of the stem portion may be about two thirds the length of the transverse dimension of the segment shaped cross member portion or greater.

Advantageously, it is believed the stem portion prevents or more efficiently alleviates * .. * * *

* .. the lock being opened by 'bumping' since it better protects bumping of the last * * tumbler pin of the cylinder lock assembly stopping a bump key being inserted * * MOO sufficiently far enough into the slideway to effect the lock being opened (unless the * * bump key was also provided with the co-operable notched or recessed formation). 00 00 * * * * *

Preferably, the blocking member is made of plastics or the like or other resilient material.

Preferably, the cross member portion and stem portion of the blocking member are integrally formed and the blocking member may be moulded in one piece.

The cross member portion will usually be a snug fit in the transverse slot in the plug and retained therein by an interference fit and by the securing or locking means where provided (usually once the plug has been assembled to the lock body).

The stem portion will usually be a snug fit in the longitudinal slot and retained therein by an interference fit.

Further advantageous features of the present invention will be apparent from the following description and drawings.

An embodiment of a cylinder lock in accordance with the present invention will now be described, by way of example only, with reference to the accompanying FIGURES of the drawings:-* 00 * * * * SO * * * 000O * * 00*0 * * ** * * * * . * * FIGURE 1 shows schematically the installation of a blocking member in a lock cylinder plug of a cylinder lock in accordance with the present invention and insertion of a matching key into the plug; FIGURE 2 shows an enlarged view of the blocking member shown in FIGURE 1; FIGURE 3 shows an enlarged plan view of the cylinder plug shown in FIGURE 1 without the blocking member, and FIGURE 4 shows and end view of the cylinder plug looking in the direction of arrow X. Referring to the FIGURES of the drawings, FIGURE 1 shows a key K having permutation lock recesses r defined by teeth or bits T co-operable with tumbler pins -not shown -of a cylinder lock (not shown) in known manner. The key K is inserted into a plug 1 of the cylinder lock, said plug being fitted, in use, into a lock body (not shown) in a generally known manner (see e.g. the arrangement shown in US Patent Specification No. 4294093). * * * * * * * 0 * * *

* * * * * * * * * * * * ** * * * * * * * * * ** * FIGURE 1 shows a plastics blocking member 2 of T-bar shape to be installed at one end la of the plug 1 in the direction of arrow X in a manner which should readily be appreciated from FIGURE 1. Segment shaped cross member portion 2a of T-bar blocking member 2 is received in transverse slot lb of plug 1 and integral rectangular stem portion 2b of member 2 is received in adjoining longitudinal slot lc on plug 1 (see FIGURE 2). The longitudinal slot lc is parallel to the axis of the plug 1. Cross member portion 2a is an interference fit in slot lb. Whilst the previous UK Patent Specification No.GB 2495714A of the Applicant shows a segment shaped blocking member received in a transverse slot in the plug, in the embodiment as shown in FIGURE 1 and 2 of the present patent specification, the shape of the blocking member 2 has, advantageously, been modified to include the integral rectangular stem portion 2b. In turn, the cylindrical plugl has been modified to include the longitudinal slot lc of matching configuration to the stem portion 2b. Rectangular stem portion 2b extends centrally at right angles to cross member portion 2a from straight edge portion 2a'of cross member portion 2a and is of greater thickness or height (1mm) than the cross member thickness t.

The transverse dimension (3 5 mm) of the stem portion 2b is about half the transverse dimension (8mm) of cross member portion 2a.

The height (1 mm) of the stem portion 2b is about half the height dimension of the cross member portion 2a and the length L of the stem portion is about two thirds (5-6 mm) of the length (8mm) of the transverse dimension of the cross member portion 2a.

As should be evident from FIGURE 1, key K is provided with a notched or recessed formation K1 co-operable with the blocking member 2 to allow the key K to be slidden in slideway ld a sufficient extent to open the lock on rotation of the key with the plug 1 in a generally known manner. A key (not shown) without the formation K1 would be prevented by the blocking member 2 from being slidden far enough into the plug to open the lock. * * * * * * * * * *

** * * In practice, the profile of the key K will be restricted or exclusive to the Applicant. * * **** *

* The shape of the blocking member 2 is thought to be advantageous in providing additional strength, durability, ease of assembly and manufacture. Importantly, the stem portion 2b should provide greater resistance or prevention of opening the lock by bumping' more particularly with regard to the last tumbler pin (not shown) of the lock assembly. * * * * * . * . * * ** *

The plug 1 is provided with a circular groove 1 e near end la. Securing or locking means in the form of a cirelip (not shown) is seated in the groove ld to retain the plug to the lock body.

Most importantly, the circlip has the function of securing the blocking member 2 in place in the sloth lb and lc to alleviate or prevent the blocking member being manipulated or lifted out of place by a picking tool (not shown) in order to open the lock.

In use, the circlip will overlap the stem portion 2b of the blocking member 2 thereby holding the stem portion in said longitudinal slot lc.

Further according to the present invention there is provided a cylinder lock or cylinder plug having any feature or function or combination thereof derivable from the description and/or FIGURES of the drawings of this patent specification.

Preferably, the blocking member has substantially the relative dimensions (or substantial dimensions) as shown in FIGURE 2 of the accompanying drawings.

It is to be understood that the scope of the present invention is not to be unduly limited by the particular choice of terminology and that a specific term may be replaced or supplemented by an equivalent or generic term.' Having' may be replaced by 'comprising' or 'including'. Further it is to be understood that individual features, method or functions relating to the cylinder lock, plug or blocking member might be patentably inventive. The singular may include the plural and vice versa.

Additionally, any range mentioned herein for any parameter or variable shall be taken to include a disclosure of any derivable sub-range within that range or of any * 00 * * * * ibe * * 0000 00 00 * * * * particular value of the variable or parameter arranged within, or at an end of, the range or sub-range. * **

* * * * .. * * *

* * * * . *** *

Claims

CLAIMS1.A cylinder lock comprising a plug rotatable in a lock body to open the lock, the plug having a slideway for receiving a key of matching configuration to the slideway, a blocking member preventing said matching key being slidden axially in the slideway a sufficient extent to open the lock on rotation of the key with the plug, unless said matching key is provided with a notched or recessed formation co-operable with the blocking member, the blocking member being T-shaped and having a cross member portion received, in use, in a transverse slot in the plug, and having a stem portion received, in use, in a longitudinal slot in the plug, the blocking member bridging an end of the slideway such that, in use, the blocking member overlaps an edge of said matching key opposed to a key edge having permutation lock recesses or teeth. O,80 * * * O4. * * * * * SO * * * * * **0 * * *
* * * * 2. A lock as claimed in claiml in which the blocking member is secured in place in * * * the slots by securing or locking means.
3. A lock as claimed in claim 2 in which the securing or locking means is a circlip.
4. A lock as claimed in claim 3 in which the circlip retains the plug within the lock body.
5. A lock as claimed in any one of claims 2 to 4 in which the securing or locking means seats in a groove in the plug and overlaps said stem portion of the blocking member thereby holding said stem portion in said longitudinal slot.
6. A lock as claimed in any one of the preceding claims in which the cross member portion is of segment shape and fits snugly into the transverse slot which is of matching configuration.
7. A lock as claimed in any one of the preceding claims in which the stem portion is of rectangular configuration and fits snugly into the longitudinal slot.O060. * .
8. A lock as claimed in claim 7 in which the rectangular stem portion extends centrally at right angles to the segment shaped cross member portion from or adjacent to a straight edge portion of said cross member portion. * *0000 10.
A lock as claimed in claim 8 in which the rectangular stem portion is of greater ID * * Se * * thickness than the thickness of cross member portion. * * 00 * * * 00841 *
10. A lock as claimed in claim 9 in which the rectangular stem portion is double the * * thickness of the cross member portion.
11. A lock as claimed in any one of claims 7 to 10 in which the transverse dimension of the rectangular stem portion is about half the transverse dimension of the segment shaped cross member portion.
12. A lock as claimed in any one of claims 7 to 11 in which the height of the rectangular stem portion is about half the height of the segment shaped cross member portion.
13. A lock as claimed in claim 6 or any claim dependent therefrom in which the length of the stem portion is about two thirds the length of the transverse dimension of the segment shaped cross member portion or greater.
14. A lock as claimed in any one of the preceding claims in which the blocking member is made of plastics or the like or other resilient material.
15. A lock as claimed in any one of the preceding claims in which the cross member portion and stem portion of the blocking member are integrally formed.
16. A lock as claimed in claim 15 in which and the blocking member is moulded in one piece.
17. A lock as claimed in any one of the preceding claims in which the cross member portion is a snug fit in the transverse slot in the plug and retained therein by an interference fit and by the securing or locking means where provided.
18. A lock as claimed in any one of the preceding claims in which the stem portion is a snug fit in the longitudinal slot and retained therein by an interference fit.
19. The combination of the lock as claimed in any one of the preceding claims and a matching key provided with a notched or recessed formation co-operable with the blocking member.
20. A plug and blocking member for the lock as claimed in any one of the preceding claims. SO$0 * . *SO OOusOoS* ** II 0 * * * ** * * 7 * * * 0* * 7 * SOO. *