GB2277123A - A security lock for a cabinet - Google Patents

A SECURITY LOCR FOR A CBIET The present invention relates generally to a security lock for a cabinet.

Although the present invention will be described hereinafter with particular reference to its application as a security lock for a vending machine cabinet, this is without prejudice to the generality of the invention which may be applied to any situation in which a highly robust security lock is required utilising relatively simple inexpensive components.

The increasing popularity of vending machines has resulted in their proliferations in many relatively unsupervised environments. Partly in the case of vending machines for cigarettes, the value of the product contained in the machine is relatively high and an incentive to theft by breaking and entering the machine. Even if the machine is only partly full, the value of the contents is represented by the cash inserted by genuine customers, and it has to be appreciated, therefore, that the full value of the contents of a vending machine may be lost each time the machine is broken open. This represents a considerable risk to the automatic vending industry, and attempts to make vending machines secure against vandals or violent thefts are continually being made.However, because vending machines are primarily intended for the purpose of attracting genuine customers it is important that the appearance of the machine be appealing and this runs contrary to the requirement for greater security since the latter requires small areas of glass (ideally less than the dimensions of the individual product units (reinforced steel, heavy locks and a thick, robust structure).

The obvious point of weakness of a vending machine cabinet is the junction line between a base of the cabinet and the front door or panel which is opened to allow introduction of fresh product and removal of cash takings. The junction line between the front panel and the casing body is also a potential weakness, and one known reinforcing structure, which comprises a thick heavy band of steel around the central portion of a vending machine, has unfortunately had an adverse effect since it constitutes a reaction plate against which the front panel of the machine can be forced into a hingelike bend to allow access to at least some of the products. This also completely ruins the machine so that the loss to the vending machine proprietor is, in such circumstances, much greater than the value of one load in the machine even though the cash takings for a load or part load may be protected.

There are also known vending machines in which the casing is in fact produced in two longitudinally separated parts as front and rear half-shelves, which can be pivoted apart to allow access to the interior for reloading and withdrawal of cash. These machines are particularly vulnerable to attach and the present invention seeks to provide a security lock for such a machine.

According to one aspect of the present invention, therefore, a security lock for a vending machine or like cabinet, comprises two substantially laminar parts each of which can be separately secured to a respective part of the vending machine or cabinet, the first of the said parts having an apertured tongue projecting therefrom and the other part having an opening which is in register with the aperture in the tongue when the said two parts are in the first predetermined relative configuration (namely the closed configuration) and a removable retainer the cross-sectional shape of which substantially matches that of the said apertures, the said retainer housing a lock barrel and having a displaceable locking pin or pins (or catches) which can be displaced between a retracted position within the said retainer and an extended position projecting from the said retainer such as to obstruct removal of the retainer from the aligned said apertures, the retainer itself preventing separate of the said two substantially laminar parts from the said first predetermined relative configuration.

A lock of this structure has a number of advantages over conventional locks used for this purpose. First, and most importantly, it has no moving parts exposed to the exterior which can be forced by insertion of a tool. By contrast, known conventional locks, such as padlocks, can be forced off their hasp by relatively simple means known to criminals.

The attachment of the said two substantially laminar parts is of particular significance, and preferably the said two substantially laminar parts have a plurality of fixing holes by which they can be secured to the vending machine or like cabinet by coach bolts the heads of which are rounded so as not to allow purchase for any tool.

Likewise, it is preferred that the said fixing holes have counterbored portions the axial depth of which is less than the axial extent of the heads of the coach bolts to be used for fixing the said laminar parts to the vending machine or other like cabinet. Such counterbored portions need only be of relatively shallow depth, such as not to weaken the strength of the plate at the fixing, but this contrivance makes it extremely difficult to remove the head of the coach bolt by shearing it from the coach bolt shank since any forced applied to the coach bolt head transversely of the shank is resisted by engagement of the head itself in the recess in the plate so that any such force is not transmitted to the shank.

In the preferred embodiment of the invention the said other laminar part has two substantially parallel plate portions with respective apertures aligned with one another and spaced by a distance such as to allow the said tongue on the said one part to pass between them.

In this way, upon insertion of the retainer, this is guided by three aligned apertures the two outer apertures of which are fixed in relation to one another and the aperture intermediate the two outer apertures is formed in the relatively movable tongue. No force applied in the direction of withdrawal of the tongue from the location between the said two plate parts can cause rocking of the retainer.

It will be appreciated that the locking pin or pins (or catches) of the lock barrel in the retain do not have to be of substantial strength since the retainer itself is housed entirely within the lock and exposes no edge or face at which a withdrawing force can be applied. The strength of resistance in the lock is provided by the relatively massive dimensions of the retainer itself since it is the retainer which prevents separation of the two substantially laminar parts which in turn are secured in use to the two relatively movable parts of the cabinet.

The length of the said retainer may be such that the end face thereof exposed to the environment is substantially flush with the surface of that part of the said other part of the lock in which the said aperture is formed.

The term 11substantially flush" will be understood herein to mean so positioned that the face of the retainer lies within a range only just above to just below the plane defined by the surface to which it is substantially flush. The intention here is to so devise the positioning of the end face of the retainer that it is impossible to gain a purchase between the retainer and the aperture through which it passes, either to force the retainer more deeply into its housing or to seek to draw it from the housing.

A particularly robust structure for such a lock is provided by forming the said two substantially parallel plate portions of the said other part as part of a boxlike projection from the face of the said other part.

The said box-like projection having a slot in the side wall thereof through which the said tongue can project into the box-like projection in the said predetermined relative configuration of the said two lock parts.

In this way the lock provides an effectively closed boxlike external appearance having no weakness that can be attacked by implement. In the embodiment having a boxlike projection, the rear face of the box may comprise a solid plate in alignment with the said aperture or apertures whereby to resist any attempts forcibly to drive the said retainer through the security lock towards the interior of the vending machine or other like cabinet. An inverted configuration may also be formed in which the said box-like projection faces inwardly towards the vending machine or like cabinet and is received in a socket therein, rather than being on the outside and projecting therefrom. This has the advantage of providing an exterior surface without any projections which may be an incumbrance in normal use.

The said first substantially laminar part from which the tongue projects may be so formed that the tongue itself is offset from the plane of the said part, and may incorporate a transverse flange as an upstanding wall from which the tongue projects.

One embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a vending machine to which a lock formed as an embodiment of the present invention has been fitted; Figure 2 is an enlarged perspective view of the lock illustrated in Figure 1; Figure 3 is a sectional view taken on the line III III of Figure 2, showing the components of the lock separated from one another; Figure 4 is a section similar to that of Figure 3, showing the components of the lock in their closed or working position; Figure 5 is a perspective view of a further embodiment; and Figure 6 is a perspective view of another alternative embodiment.

Referring now to the drawings, Figure 1 illustrates a vending machine generally indicated 11 comprising a casing having a front casing half 12 and a rear casing half 13 separated by a junction line 14. The casing 12 is supported on legs 15 to raise it to a convenient height for use. In other embodiments the legs 15 may be a cabinet support or column.

The front casing half 12 has a plurality of elongate vertical glazed apertures 16 each having a respective draw pull at the lower end through which individual units 18 of the vendible product can be withdrawn upon insertion of coins into a coin release mechanism represented by the coin slot 30 in Figure 1. Other machines may have a different product dispensing arrangement. In particular the machine may have an open recess for the product delivery and a motor driven delivery mechanism.

The two casing halves 12, 13 are hinged together along their right-hand edge (not visible in Figure 1) by secure internal hinges, and held shut along their right-hand edge by a security lock 19 which forms the embodiment of the present invention. The security lock 19 comprises two substantially laminar interengageable lock parts 20, 21 the details of which are shown on an enlarged scale in Figure 2.

Referring now to Figure 2, the lock part 20 comprises a substantially flat plate 22 from which projects a boxlike projection 23 having a front or outer face 24 with a rectangular aperture 25 formed therein.

The plate 22 has an edge 26 which, when the lock is fitted to the cabinet 11, is in substantial alignment with the junction line 14 and the face of the projection 23 nearest this edge is, in fact, substantially coplanar therewith. Extending parallel to the edge 26 in this face of the box-like projection 23 is a slot 27 one edge of which is defined by the fact of a planar internal wall 28 parallel to the plate 22 and the outer" wall 24 of the box like projection 23, in which there is formed a rectangular aperture 29 in alignment with the rectangular aperture 25 in the face 24.

The other plate like part 21 of the lock 19 comprises a substantially rectangular plate like portion 31 along one edge 32 of which extends a transverse flange 33 from a central portion of which, parallel with the plate 31, extends a rectangular tongue 34 which, when the two plates 22., 31 are aligned in a coplanar fashion with the edges 26, 32 thereof parallel, is in alignment with the slot 27. The tongue 34 has a central rectangular aperture 35 the dimensions of which are substantially the same as the aligned apertures 25, 29 in the box like projection 23 and the position of which is such that all three apertures are substantially in register when the edge 32 of the part 21 is in contact with the edge 26 of the part 20.

The two parts of the lock are held together by a retainer 36 which has a substantially rectangular cross section matching that of the three aligned apertures 25, 29 and 35 and a length approximately the same as the distance from the surface of the plate 22 to the surface of the "outer" face 24 of the box like projection 23. The retainer 36 can thus be inserted into the box like projection 23 passing through the aligned rectangular apertures 24, 29, 35 until its end face engages the face of the plate 22, at which points its other end face 38 substantially flush with the "outer" face 25 of box like projection 23. In this position of the retainer 36 the tongue 34 is securely held within the box-like projection 23 and the two lock parts 20, 21 thus fixed against separate.The retainer 36 can be held in position within the box-like projection 23 by two opposite pins 38, 39 which can be caused to project from the lateral surfaces of the retainer 36 by rotation of a lock barrel 40 utilising a key 41 inserted through a key hole slot 42 in the end of the log barrel 40. The log barrel 40 may be of any conventional type and does not require to be a highly sophisticated lock since the primary function of the lock is to deter casual vandalism or theft from the vending machines, and is unlikely to meet with the more sophisticated criminal having the ability to pick a lock without forcing it.

The relative positions of the component described in relation to Figure 2 can be seen in Figures 3 and 4. The pins 38, 39 do not require to be of great strength since the design of the lock is such that no material force can be applied in any direction which will tend to cause shearing of the pins and their function is therefore to hold the retainer 36 in place against removal utilising relatively low forces. A convenient type of lock barrel is one in which the key hole slot is circular to receive a hollow tubular key with appropriate notches or recesses in its peripheral edge. Such a lock resists the insertion of a tool which would be strong enough to exert in outward force for shearing the pins 38, 39. Any attempt to insert a lever between the retainer 36 and the periphery of the aperture 24 is frustrated by the strength of the material from which the rectangular projection 23 is made, preferably steel sheet, and by the close fit between the retainer 36 and the aperture 25.

Any attempt to drive the retainer 36 inwardly is resisted by the strong metal plate 22 which forms the back wall of the projection 23 as can be clearly seen in Figures 3 and 4.

Finally, the parts 20, 21 are secured to the respective casing parts 12, 13 of the vending machine 11 by coach bolts 43 having rounded heads 44 received in counterbored apertures 45 which receive a part of the coach bolt head 44 to prevent any attempt at removal by striking the head sideways to shear it from the shank 43.

In use of the lock of the present invention the retainer 36 can be withdrawn, upon introduction of the key 41 into the slot 42 and rotation through an angle such as to cause the pins 38, 39 to retract into the retainer 36 allowing the retainer 36 to be withdrawn completely from the lock. This is the only removable part of the lock and the key 41 may be so shaped as to be trapped in the slot 42 when the angular position of the key 41 is such that the pins 38, 39 are retracted.

Figure 5 illustrates an embodiment in which a lock part 120 is carried on a partially encircling strap 140 hinged at 141 to a fixing plate 142. A plate part 121 is fixed in the same way as the corresponding part 21 of the embodiment of Figures 1 to 4.

By contrast, in the embodiment of Figure 6 the lock part 220 is carried on a strengthened strap 240 having inclined edges 241 and carried by a hinge 242 on a further strap 243 which extends entirely around the back of the cabinet and carries the lock plate part 221 which corresponds to the part 21 in the embodiment of Figures 1 to 4.