GB2054021A - Lock - Google Patents

Abstract

A lock comprising a die-cast body with respective openings extending inwardly from the opposite ends thereof, one of which accommodates the end parts of a hoop-like locking element 40 and a bolt member engageable therewith, and the other of which receives a key-operable locking mechanism 30 for moving the bolt member between locking and releasing positions, together with a retaining member for said locking element, the two openings being closed by closure plates 18, 28 which extend over substantially the entire ends of the body so as to reinforce same. <IMAGE>

Description

SPECIFICATION Locks This invention relates to locks, that is to say locks of the kind comprising a lock body incorporating a key-operable locking mechanism and a hoop-like locking element movable between an open position in which one end part thereof is spaced from said body and a closed position in which both end parts are received in said body, said locking mechanism being adapted to lock said locking element in said closed position. Such locks are hereinafter referred to as being of the kind specified.

When the locking element is in the form of a rigid, generally U-shaped shackle, the lock is of the type usually referred to as a padlock, but the locking element may take other forms, such as an elongated flexible member.

The present invention is primarily concerned with the body and locking mechanism of a lock of the kind specified regardless of the form of the locking element. Conventionally, the body of such a lock may be formed as a solid block of material, such as steel or brass, drilled as appropriate to receive the ends of the locking element at one end of the body, and at the other end to receive the locking mechanism, with various other bores having to be drilled to allow assembly of components such as a sliding bolt, such other bores subsequently being externally plugged. This method of construction offers a strong body, but it is expensive to produce both in terms of quantity of materials used and operations performed.

Another way of constructing the body of such a lock is by using an assembly of flat plates stacked and riveted or otherwise secured together. Such a body is also quite strong, but several different types of plate are needed, each with appropriately shaped apertures so as collectively to define the required internal cavities for the components of the locking mechanism and other parts. Thus, assembly is relativeiy difficult and the large number of different parts makes the design relatively expensive to produce.

Yet another way of constructing the body of such a lock is by means of die-casting. In this case, the body can quite readily be shaped internally as necessary, but the construction is inherently weaker than such other constructions.

According to the present invention we provide a lock of the kind specified whereby the body is formed as a die-casting with a respective opening extending inwardly from the opposite ends thereof, the end parts of the locking element and a sliding bolt member engageable therewith are received in one of said openings, the key-operable mechanism for moving said bolt member between locking and releasing positions is received in the other of said openings, and each of said openings is closed by a respective plate extending over substantially the entire end of the body.

The use of such closure plates makes it possible thereby to reinforce and strengthen the body as compared with a body formed wholly as a diecasting, and yet the benefits of simple assembly are retained. Additionally, other benefits may be achieved. For example, the bolt member may comprise a pair of bolts slidable in opposite directions so as to engage with both end parts of the locking element.

One end part of the locking element may extend through the body and into the opposite opening and be fitted with a retaining element within said opposite opening. A compression spring may be arranged between the closure plate of said opposite opening and the one end part of the locking element so as to bias the latter into its open position.

Typically, the body may be formed as a zincbased die casting with closure plates of steel.

The invention will now be described by way of example with reference to one embodiment of lock in accordance therewith, as illustrated in the accompanying drawings, wherein FIGURE 1 shows a top plan view of the die cast body component; FIGURE 2 shows a vertical section on the line Il-Il of Figure 1; FIGURE 3 shows an underneath plan view corresponding to Figure 1; FIGURE 4 shows a vertical section through the assembled lock in the same plane as Figure 2; and FIGURE 5 shows a section on the line V-V of Figure 4.

In the illustrated embodiment, the body of the lock is generally flat, although of increased width in its mid-region, and a rigid shackle extends from one end (hereinafter for convenience called the "upper" end) of the body.

The body 10 is formed as a zinc-based die casting having an opening 11 at the upper end surrounded by a peripheral rim 11 a within which there is a shallow rebate 12 affording a shoulder 1 2a adjacent to the rim. A rectangular recess 13 is formed centrally of the upper end of the body and a central bore 14 extends inwardly from the recess 1 3 and has flat lateral extensions 1 4a which extend along the full length of the bore up to the shoulder 12a. The bore 14 terminates in a circular aperture 1 5 surrounded by a shoulder 15a. A pair of spaced, parallel, outer bores 1 6 and 1 7 also extend inwardly from the rebate 12 adjacent to opposite sides of the body. The bore 16 terminates in a tapering end portion 16a.

The bores 14, 16 and 17 all communicate at their inner ends with an opening 21 formed from the lower end of the body 10. The lower end opening 21 is surrounded by a peripheral rim 21 a and affords a shallow rebate 22 surrounded by a shoulder 22a. A main recess 23 extends inwardly from the rebate 22 and is formed with a wide central portion 23a tapering to a narrow side portion 23b. On the side of the body remote from the narrow side portion of the main recess 23, there is formed a bore 27 which extends inwardly from the rebate 22 and is arranged coaxially with the bore 1 7. The bore 27 is of larger diameter than the bore 17 so as to define a shoulder 26 where they intersect in the plane of the circular aperture 15 whereby the central bore 14 communicates with the central portion 23a of the main recess 23.As can be seen, the tapered end portion 1 6a of the bore 1 6 opens out into the narrow side portion 23b of the main recess 23.

A pin-tumbler lock mechanism indicated generally at 30 is inserted into the main recess 23 from the lower end of the body 10. The lock mechanism 30 is provided with a rotary barrel 31 which is located within the circular aperture 1 5 and has an eccentric sector-shaped nose 23 which projects into the central bore 14. A disc 33 is introduced into the bore 14 from the upper end of the body and is formed with a pair of like recesses 34, one of which receives the nose 32.

At its upper side, the disc 33 is formed with a pair of diametrally opposed, upwardly directed lugs 35.

A pair of generally flat bolt members 36 together with compression springs 37 which extend into bores 37a, are introduced into the rectangular recess 13. The bolt members 36 are formed with lugs 38 at their underside, and with lateral ears 38a which enter into the lateral extensions 1 4a of the central bore 14, as best seen in Figure 5. As will be apparent, the springs 37 bias the bolt members 36 outwardly so that the lugs 38 engage the lugs 35 of the disc 33. The bolt members 36 are so dimensioned that the outer ends thereof project into the outer bores 1 6 and 1 7, but rotation of the lock mechanism barrel 31 causes the disc 33 to rotate and thereby withdraw the bolt members 36 inwardly by coaction of the lugs 35 and 38 against the force of the springs 37.

The outer end of the bolt members 36 are formed with recesses 39 which have hook-like engagement with the end parts of the locking element, which in the embodiment illustrated takes the form of a rigid shackle 40. In this case, the shackle 40 is formed with one shorter leg 41 which enters the bore 16, and one longer leg 42 which enters the bore 1 7 and extends into the bore 27. The two legs of the shackle are formed with aligned notches 41 a and 42a where they are engaged by the bolt members 36, as seen in Figure 4.

To secure the shackle 40 in permanently assembled relationship with the body 10, a retaining washer 43 is engaged with the longer leg 42 after the latter has been inserted into the body, the washer 43 bearing against the shoulder 26 so as to prevent upward withdrawal of the entire shackle from the body 10, whilst the length of the bore 27 is such that when the washer 43 engages the shoulder 26 the end of the shorter leg 41 is spaced outwardly away from the upper end of the body 10.

A compression spring 44 is disposed in the bore 27 to act on the washer 43 and bias the shackle outwardly so that the lock is self-opening when the locking mechanism is released.

A closure plate 1 8 for the upper end of the body 10 is formed with apertures 1 8a through which the legs of the shackle 40 extend. The closure plate 1 8 is assembled with the shackle 40 before the longer leg 42 of the latter is assembled with the body as previously described. After fixing the retaining washer 43, the upper end closure plate is slidden along the legs of the shackle into the shallow rebate 12, and the rib 11 a at the upper end of the body is deformed inwardly so as to overlie the margin of the plate 18, as shown at 11b in Figure 4.

Likewise, a lower end closure plate 28 is placed in the shallow rebate 22, with the other end of the spring 44 bearing on such plate, and the rim 21a at the lower end of the body is deformed inwardly so as to overlie the margin of the closure plate 28 as shown at 21 b in Figure 4.

By making the plates 18 and 28 of a suitable material, and of appropriate thickness, these plates serve not only to close the ends of the body, but also to reinforce and strengthen same. By the use of such strengthening plates, it is possible to form the body 10 with larger cavities than would otherwise be the case, and accordingly it is possible to incorporate into the lock stronger components than has previously been possible in locks utilising die cast bodies. In particular, the bolt members 36 are each substantially larger and stronger than the bolt members previously employed in locks of this general type. Indeed, it is to be noted that the preferred embodiment incorporates two such bolt members, whereas previously in locks of this generai design it has only been possible to accommodate one, much weaker, bolt member.

Although, in the embodiment illustrated, the lock includes rigid shackle. it is to be understood that this may be replaced by a flexible locking element having rigid end parts similar to the legs of the shackle illustrated. Likewise, whilst the illustrated embodiment includes a pair of bolt members, it will be appreciated that in some cases it may be appropriate to incorporate only a single bolt member wich engages the shorter leg of the shackle. Again, whilst in the illustrated embodiment reference has been made to a pintumbler locking mechanism, it will be appreciated that other types of locking mechanism could be employed if desired.

Claims (6)

1. A lock of the kind specified wherein the body is formed as a die-casting with a respective opening extending inwardly from the opposite ends thereof, the end parts of the locking element and a bolt member engageable therewith are received in one of said openings, the key-operable mechanism for moving said bolt member between locking and releasing positions is received in the other of said openings, and each of said openings is closed by a respective plate extending over substantially the entire end of the body.

2. A lock according to Claim 1 wherein the bolt member is slidably guided in a recess forming part of the opening at one end of said body.

3. A lock according to Claim 2 wherein two such bolt members are provided in said recess and are arranged to be moved in opposite directions by the key-operable mechanism.

4. A lock according to any one of the preceding claims wherein the locking element extends through the body and into the opposite opening and is fitted with a retain element within said opposite opening.

5. A lock according to Claim 4 wherein a compression spring is arranged between the closure plate of said opposite opening and the one end part of the locking element so as to bias the latter into its open position.

6. A lock of the kind specified substantially as hereinbefore described with reference to and as shown in the accompanying drawings.