GB2124026A - Key operable lock - Google Patents

Abstract

A key operable lock comprises a generally cylindrical part 7 which has a slot 12 from which a key laterally projects when inserted in a keyhole 10. The cylindrical part 7 is mounted for rotation in a body part 8 and held in a locked position by differ pins, the body part 8 having circuit elements such as micro- switches positioned in slots 14 which are actuated by the projecting lateral edge formations of the key when the cylindrical part 7 is rotated from the locked position on turning the key. The lock may be used in a fuel dispensing installation. <IMAGE>

Description

SPECIFICATION Key operable lock TECHNICAL FIELD OF INVENTION The invention relates to a key operable lock for actuating electrical circuitry, particularly though not exclusively for monitoring the dispensation of fuel such as petrol at fuel pumps.

According to the invention there is provided a key operable lock for actuating electrical circuitry, comprising a generally cylindrical part and a body part the two parts being mounted one within the other and one being rotatable with respect to the other the two parts being held in a cocked position by pin means and one part carrying circuit elements operable to make or break electrical circuitry by means associated with the one part when the one part is rotated from the locked position or turning the key.

The one part may be a rotatable plug which may be held captive in the body part and which may have a key slot for receiving the shank of the dey.

The plug may have a through slot and at substantially 90 thereto a linear array of differ pins, may be less than the width of the key so that the key may project laterally beyond the plug in use.

The body part may have a bore in which the plug is received and may have a through slot extending between the outer surface of the body part and the bore, which slot may afford a seating for one or more circuit elements.

The or each circuit element may comprise a micro-switch.

Preferably there may be a plurality of microswitches.

The means associated with one part may comprise the projecting part or parts of the key which part or parts may contact and actuate the micro-switches.

The projecting parts of the key may have a edge configuration whereby only selected micro-switches may be actuated.

The boundary of the slot may provide a stop preventing further turning of the key.

The key may be turned through substantially 45".

The slot may be a diametral slot.

There may be more than one diametral slot, whereby to provide further seatings for microswitches.

A key operable lock for actuating electrical circuitry associated with a fuel pump is hereinafter described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS Figure 1 is an end elevational view of a key; Figure 2 is a plan view of the key of Fig. 1; Figure 3 is a perspective view of one part in the form of a cylindrical plug; Figure 4 is a plan view to a smaller scale of the key of Figs. 1 and 2 in the plug of Fig. 3; and Figures 5 and 6 are respective plan and perspective views of another part in the form of a body for receiving the plug of Figs. 3 and 4.

Referring to the drawings the separate parts of the lock are shown separately for clarity.

Referring to the Figs. 1 s 2 the key 1 shown has a shaft or shank 2 projecting from a cylindrical hand grip part 3. The part 4 of the key shank 2 has surface profiles appropriate for operating differ pins of the lock. The part 5 of the shank 2 has at its lateral edges profiles or cut-outs 6 as shown.

The lock itself comprises one part in the form of a generally cylindrical plug 7 which is held captive in the longitudinal direction, but can rotate with respect to a body part 8 in the bore 9 of which the plug 7 is received. The plug 7 has a T-shaped key-hole 10 to receive the shank 2 of the key 1, a series of bores 11 in which differ pins are received and a longitudinally extending diametrical slot 1 2. The shank 2 of the key 1 is wider than the diameter of the plug 2 so that the edges 6 of the shank 5 protrude from the plug 7 through the slot 12 when the key 1 is in the plug 7 (Fig. 4).

The body part 8 is generally cylindrical, with two opposed flats 1 3 in each of which there are slots 1 4 which extend through to the bore. The slots are aligned in the diametrical sense, as shown in Fig. 5. The bore is lined by a sleeve 1 5 which provides a boundry surface for the slots 14 and which is interrupted over its length to provide clearance for the key.

Electrical elements (not shown) in the form of a plurality of micro-switches are mounted in the slots 14; in the embodiment shown there are four micro-switches in the slots on one side and five in those on the other side, thus making nine in all. The micro-switches are connected to electrical circuitry.

The body part 8 also has differ pins (not shown) which co-operate with aligned differ pins in the plug 7.

Assuming the plug 7 is mounted in the body part 8 which is itself fixedly mounted in a console with its micro-switches connected up to electronic circuitry such as a monitoring system for a set of petrol pumps and it is desired to activate the circuitry to moniter a particular pump and its usage, an operator inserts his or her key 1 into the key hole 10.

The part 4 of the shank acts on the differ pins so that those of the body part 8 are withdrawn thereinto by the differ pins of the plug 7 and the cylindrical surface between the two parts 7 and 8 is unobstructed by differ pins.

The lock is now in the unlocked state.

The lateral edges 6 of the shank 5 project through the diametral slot 1 2 of the plug 7 beyond the outer cylindrical surface of the plug. (There is clearance in the body part for this projecting part of the key shank, provided by the sleeve 1 5 as described).

When the key 1 is turned, the plug 7 turns with it, and the projecting parts 6 of the shank act on the micro-switches which are actuated in dependence on the profile or code carried by the outer edge of the part 6 of the shank 5. The relevant part of the electrical circuitry is actuated and can monitor the pump usage. The key 1 is held captive, during this rotation to the position to actuate the microswitches, which in the emodiment shown is through an angle of 45 . The edge of the sleeve 1 5 acts as a stop limiting rotational movement of the key 1.

The edges 6 of the key are radiussed to provide a smooth launching action to actuate the micro-switches.

In order to de-actuate the circuitry, and to lock the system, the key 1 is rotated in the opposite sense to return the micro-switches to their initial state, and the key 1 is then withdrawn. There is thus a two-stage operation of insertion/withdrawal and rotation.

Each key 1 can be "coded" for a particular operative so that when the key is inserted and turned, the appropriate circuitry is actuated to identify the particular operative using the system. In this way the volume of petrol dispensed can be monitored for each operative.

It will be understood that more or fewer micro-switches than the ones described can be used, and also that the key can be of different shape in end elevation, for example "Y" aor "X" shape, with a commensurately shaped key-hole 10. Also more in one slot can be used on the flats of the body part.

Also, the lock can be used for other monitoring or security purposes other than the monitoring of use of petrol pumps described.

In every embodiment, the micro-switches can be permanently "open" or "closed" then the lock is locked.

The edges 6 of the key 1 in every embodiment provide means associated with the one part, the plug, to act on the circuit elements, the micro-switches in the embodiment described.

Claims (11)

1. A key operable lock for actuating electrical circuitry, comprising a generally cylindrical part and a body part the two parts being mounted one within the other, one being rotatable with respect to the other and there being pin means for holding the two parts together in a locked position, one part carrying circuit elements operable to make or break electrical circuitry by means associated with the one part when the one part is rotated from the locked position on turning the key.

2. A lock according to Claim 1, the generally cylindrical part being a rotatable plua which is captive in the body part and which has a key slot for receiving the shank of the key.

3. A lock according to Claim 1 or Claim 2, the plug having a through slot for receiving the shank of the key the lateral extent of the plug being less than the width of said shank so that the key projects laterally beyond the plug in use.

4. A lock according to Claim 3, the pins comprising a linear array of differ pins extending substantially at 90 to the plane of the slot.

5. A lock according to any of Claims 2 to 4, the body part having a bore in which the plug is received and a through slot extending between the outer surface of the body part and the bore, which slot seats one or more circuit elements.

6. A lock according to Claim 5, the or each circuit element comprising a microswitch.

7. A lock according to any preceding claim, the means associated with the one part comprising the projecting part or parts of the key which part or parts is or are operable in use to actuate the or each micro-switch.

8. A lock according to Claim 7, including a plurality of micro-switches and projecting parts of the key having an edge configuration whereby only selected micro-switches are in use actuated.

9. A lock according to Claim 8, the boundary of the slot in the body including a stop for preventing turning of the key through more than a predetermined angle.

1 0. A lock according to Claim 9, the angle being 45 .

11. A lock according to any preceding claim, the shank of the key being of T-shape in cross-section.

1 2. A key operable lock, substantially as hereinbefore described with reference to the accompanying drawings.

1 3. A fuel dispensing installation including a key operable lock according to any preceding claim.