GB2210406A - improvements relating to keys - Google Patents

Abstract

A key (5, 7,) can be inserted into a cylinder lock (1), turned to the bolt-retracted position and held there against the spring return, enabling the same hand subsequently to open the door by another handle. The key head may carry a finger (6), lug (10) or shoulder enterable in a recess (4) in the lock face (1), or the head may be arranged to wedge against that face, requiring no special adaptation of the lock. <IMAGE>

Description

Improvements Relating to Keys This invention relates to keys. It is particularly concerned with those for cylinder locks, but it is applicable to keys for any lock in which the bolt or latch operated by the key is biased towards the closure or locking position.

Such locks are very often not the only device for keeping a door closed. It is quite common to have an ordinary door latch elsewhere, operable by handles or knobs on opposite sides of the door, as well as a cylinder lock operable by a key from one side (the "outside" in this specification) and by a knob on the other or "inside". It is usual for the inside of a cylinder lock to have a button or trigger by which its latch can be held retracted, and it is therefore no problem for someone going out to unlock the door and to keep it unlocked while turning the inside handle to open the door. This can be done sequentially, with one hand. Howeyer, entry is generally a two-handed operation, since the key in the spring-biased cylinder lock must be kept turned while the outside handle is used to release the ordinary latch and push the door open.Thus any load, such as a shopping basket, must be put down first and subsequently retrieved. That is tedious and inconvenient and it is the aim of this invention to provide a remedy.

According to one aspect of the present invention there is provided a key and lock combination in which the key is adapted to be engageable with a fixed portion of the lock when entered and turned to the open or bolt retracted position, whereby the key is retained in that position when the operator lets go of the key.

This can be achieved in various ways. In one form the fixed portion of the lock provides an exposed detent in which a portion of the head of the key is engageable. This head portion may be an element movable with respect to the main body of the key; for example it may be a finger pivoted to the head. The fixed body of the lock, adjacent the keyhole, may have a recess providing the detent. The finger will not impede the entry and turning of the key,--but when the bolt or latch is fully retracted the finger can be manually flicked, or possible springurged, into the recess, with which it is then in registry.

This will hold the key with the lock in the open condition, and so any other handle can then be operated by the erstwhile key hand. Alternative detent engaging elements are a sliding pin and a spring-loaded plunger, but these may be excessively complicated or expensive.

In another form the head of the key is pivoted to the shank which actually enters the lock, the pivot axis being transverse to the length of the key. In the case of the flat key form usual for cylinder locks, the pivot axis will conveniently be perpendicular to the plane of the key. A peripheral portion of the key head will then perform the function of the finger described above. This construction has the additional advantage that the key can be folded up and thus be more compact for carrying.

In a further version, the key is movable lengthwise further into the lock when in said open or bolt retracted position, such lengthwise movement bringing the head portion into engagement with said detent.

It is common for keys for cylinder locks to have one or two shoulders at the junction of the shank with the head, these appearing as rather larger teeth than those formed by the serrations along the shank. It may be possible to use these as means for retaining the key in the lock open position. The key would be operated in the normal way to release the lock, but having reached the open position the key could be pushed further in.

The or each shoulder would then engage in a recess adjacent the keyhole. This makes the key itself simpler (it can be a unitary member without moving parts) but the lock mechanism itself would have to be specially constructed.

It would be an advantage if the lock, or the member in which it was installed, needed no extra feature - not even a detent - so that one simply needed a special key in order to achieve the desired effect.

According to another aspect of the present invention there is provided a key for a lock, the key having, on the portion left exposed when entered in the lock, means for wedging against a fixed portion of the lock or the member in which the lock is installed.

Preferably, the key head is pivotally attached to the shank of the key, the pivot axis being transverse to the length thereof, and has a profile which provides the wedging action when pivoted.

For a better understanding of the present invention some embodiments will now be described, by way of example, with reference to the accompanying drawing, in which: Figure 1 is a face view of the outside of a cylinder lock with two possible keys therefor, Figure 2 is a face view of the outside of another cylinder lock with a key therefor, and Figure 3 is a side view of a key in an existing cylinder lock.

In Figure 1, the outside of a cylinder lock has a generally standard appearance, with a fixed disc 1 and the circular end of a key-receiving plug or cylinder 2 offset below the centre of the disc 1. A slot 3 for the key is normally aligned vertically, and the key can turn the plug in either direction to retract the bolt. When that is fully retracted, the slot 3 aligns with the 10 o'clock or 2 o'clock positions and with small recesses 4 in the disc 1.

One possible key 5 is of normal construction and appearance, but with the addition of an L-shaped finger 6 pivoted at one end to the head of the key, the pivot axis being perpendicular to the plane of the key. When swung back away from the serrated shank it will not interfere with insertion and turning, but when the turn is complete it can be flicked forward for its other end to engage in one of the recesses 4. The key will thus be held in that position, with the bolt retracted.

Any other door handle can then be operated by the same hand that inserted and turned the key. Once the door is opened, the finger 6 can be flicked back allowing the key to return to the median position and be pulled out.

An alternative key 7 has the entire head 8 pivoted to the serrated shank 9 about an axis perpendicular to the plane of the key, and a lug or nose 10 on the head is engageable with either recess 4 in a similar manner to the finger 6. When not in use, the head 8 may be pivoted through 1800 to overlie the shank 9, thus making it very compact.

In Figure 2 the lock has the same general outside appearance, but instead of the recesses 4, the disc 1 has recesses 11 at the 4 o'clock and 8 o'clock positions opening to the periphery of the hole receiving the plug 2. The key slot 3 has its mouth extended diametrically of the plug 2 by a groove 12 which extends to the edge and which can come into registry with either recess 11. The key 13 is of generally normal appearance, but with an extended shoulder 14 between the shank and head on the side opposite the serrations and which will extend radially beyond the plug 2. It can operate the lock in the usual manner, but when turned to the bolt retracted position, the lock mechanism will allow it to be pushed further in for the shoulder 14 to engage in one or other of the recesses 11. This will hold the key and thus the bolt retracted.

This would require special construction of the lock, which would probably be too complicated and expensive. It would be desirable to achieve the same effect on an existing lock, without making any adaptation, not even simple detents, so that one just needed a self-retaining key.

An example is shown in Figure 3, where the key 15 has a shank 16 extended by an inclined or offset portion 17 at the end of which is pivoted a head 18, the pivot axis being perpendicular to the plane of the key. The periphery of this head is non-circular and has a cam-like section 19. When adjusted so that the smallest radius of the section 19 is aligned parallel with the length of the key, the latter can be inserted and turned in the normal manner. But then by rotating the head 18 about its pivot, the section 19 will be brought to bear on the disc 1 and, since the shank cannot be withdrawn when in the bolt-retracted position, the head 18 can be wedged against the disc 1, holding that position. The door can then be operated elsewhere by the same hand.

Although described with reference to cylinder locks, it would be possible, if desired, to modify other kinds of locks and keys so that non-stable conditions can be held.

Claims (11)

1. A key and lock-combination in which the key is adapted to be engageable with a fixed portion of the lock when entered and turned to the open or bolt retracted position, whereby the key is retained in that position when the operator lets go of the key.

2. A combination as claimed in claim 1, wherein the fixed portion of the lock provides an exposed detent in which a portion of the head of the key is engageable.

3. A combination as claimed in claim 2, wherein the head portion is an element movable with respect to the main body of the key.

4. A combination as claimed in claim 3, wherein said element is pivoted to the main body of the key.

5. A combination as claimed in claim 2, wherein the head of the key is pivoted to the shank of the key, the pivot axis being transverse to the length thereof.

6. A combination as claimed in claim 2, wherein the key is movable lengthwise further into the lock when in said open or bolt retracted position, such lengthwise movement bringing the head portion into engagement with said detent.

7. A combination as claimed in any preceding claim, wherein the lock is a cylinder lock.

8. A key and lock combination substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawing.

9. A key for a lock, the key having, on the portion left exposed when entered in the lock, means for wedging against a fixed portion of the lock or the member in which the lock is installed.

10. A key as claimed in claim 8, wherein the key head is pivotally attached to the shank of the key, the pivot axis being transverse to the length thereof, and has a profile which provides the wedging action when pivoted.

11. A key substantially as hereinbefore described with reference to Figure 3 of the accompanying drawing.