A locking device

Abstract: A locking device 13 adapted to be pressed, during use, into a locking position (c.f. figure 2) and released therefrom by means of a key 19, comprising a body portion 15, having an aperture 17 therein for receiving the key 19 during unlocking, an active portion 23 for effecting locking when the device is depressed and a detent 21, attached to the body portion 15 by means of a resilient web 25, the detent 21 retaining the device 13 in its locking position when depressed, wherein interaction of the key 19 with the locking device 13 bends the resilient web 25, thereby deactivating the detent 21 and enabling the device 13 to be biased back into its unlocked position (c.f. figure 1). Such a locking device is simple to use, efficient at locking and particularly cheap to manufacture.

Description: This invention relates to locking devices, and in particular to a locking device which, during use, is pressed into a locking position and can be released therefrom by means of a key. Such a device is particularly suitable for use in a vent handle locking mechanism. Vents, such as windows, are often held closed by means of a latch which is swung into position by means of a handle rotatably mounted on the vent itself. The handle and latch rotate about a pivot secured to the vent, and the latch engages in a recess in, or simply abuts against, the frame of the vent which is solidly mounted in a wall or the like. To ensure that the handle cannot be rotated, thereby releasing the latch and allowing the vent to be opened, it is often desirable to be able to lock the handle in its closed position. A number of ways of achieving locking of the handle are known. Some of the prior art arrangements involve the driving of a pin mounted on the handle into a recess in the handle support, thereby preventing rotation of the handle relative to the support. Such prior art locks are relatively complicated, since they require at least two inter-engaging parts which incorporate camming profiles to drive the pin into the recess. Further, a key is always needed to rotate the lock to drive the pin into, and withdraw the pin out from, the recess. Such handle locks are often manufactured from metal parts, and are therefore expensive. Other prior art locking devices incorporate a stud, mounted on the handle support which is engaged by a shield integral with the handle rotated into position by means of a key. Once again, two metal parts are used, thereby making the device expensive to manufacture. Further, to lock the handle in position, it is necessary to introduce the key into the barrel of the lock. Another prior art device is known from GB-A-2222850 which discloses a handle assembly incorporating a locking device as defined in the pre-characterising part of claim 1 herein. The present invention aims to overcome the problems associated with the known prior art handle locking devices. With this in mind, a locking device according to the present invention is cheap to manufacture, requires very few parts and can be activated without the use of a key. According to the present invention there is provided a locking device adapted to be pressed, during use, into a locking position and released therefrom by means of a key, comprising a body portion, having an aperture therein for receiving a key during unlocking, an active portion for effecting locking when the device is depressed and a detent retaining the device in its locking position when depressed, characterised in that the detent is attached to the body portion by means of a resilient web, and in that interaction of the key with the locking device bends the resilient web, thereby de-activating the detent and enabling the device to be biased back into its unlocked position. According to another aspect of the present invention there is provided a vent locking mechanism according to claim 11. Preferably the locking device further comprises means for receiving a biasing means which, when the detent is de-activated, urges the device back into its unlocked position. The receiving means may be a spindle formed integrally with the body portion of the device for receiving a helical spring. In such an embodiment, the helical spring is preferably in compression when the locking device is in its locking position. The detent may include a first flange extending in a direction substantially perpendicular to the direction of motion, during use, of the locking device. In a preferred embodiment of the invention, the active portion and the detent are formed integrally. The locking device preferably further comprises means for dictating the unlocked position of the device. Such a dictating means may include a second flange extending in a direction substantially perpendicular to the direction of motion, during use, of the device. The second flange, if included, preferably extends in substantially the opposite direction to the first flange. The dictating means is preferably attached via a resilient support to the body portion. To facilitate manufacture and use of the locking device, the body portion is preferably substantially cylindrical. The whole locking device may be manufactured as a one-piece plastic moulding. If this is the case, the cost of manufacture of the device is substantially less than that of each of the known prior art devices mentioned above. Hence, this is extremely important for commercial reasons. As will be appreciated, a locking device according to the present invention is particularly suitable for use in a locking mechanism for a vent, such as a window. A vent locking mechanism of this kind preferably comprises a handle, including a locking device according to the present invention, and a base upon which the handle is rotatably mounted, wherein the locking device engages the base when in its locking position, thereby preventing rotation of the handle, and disengages from the base in its unlocked position to allow opening of the vent. When the locking device of such a mechanism is depressed, the active portion preferably enters a recess in the base and the detent interacts with a shaped part of the handle. In a particularly preferred form of the aforementioned vent locking mechanism, the locking device is accommodated within a recess in the handle, together with a biasing means for urging the locking device into its unlocked position. The biasing means may be a helical spring or some other suitable means. As will be appreciated a locking device according to the present invention may be used with a cockspur-type handle, a handle of an espagnolette bolt system, or any other suitable type of handle. A specific embodiment of the present invention is now described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a schematic partly-sectioned side elevation of a vent handle locking mechanism incorporating a locking device, according to the present invention, in its unlocked position; Figure 2 is a schematic side elevation of part of Figure 1, except that the locking device is in its locking position; and Figure 3 is a plan view of the locking device shown in Figures 1 and 2, together with a key for releasing the locking device from its locking position. With reference to the drawings, a vent locking mechanism 1 comprises a handle 3 rotatably mounted, by means of a large rivet or pin 5, on a handle base 7. The handle 3 includes a sideways extension or latch (not shown) which, when the handle is in its closed position, is able to engage a recess in, or abut against, the solidly mounted frame of the vent. Hence, it is possible to hold the vent closed without locking the handle 3. However, for additional security, it is often preferred to lock the handle 3 in position when the vent has been closed. The locking device according to the present invention enables this to be achieved in a quick and easy manner. The handle 3 includes a recess 9 which, when the handle 3 is in its closed position, overlays an opening 11 in the handle base 7. The recess 9 is adapted to receive a locking device 13 according to the present invention. The locking device 13 comprises a body portion 15 having an aperture 17 therein for receiving a key 19 during unlocking. A first flange 21 and an active portion 23, which engages the opening 11 when the locking device 13 is in its locking position, form a lower portion 24 of the locking device 13. This lower portion 24 is attached to the main body 15 of the locking device 13 by means of a resilient web 25. The aperture 17 in the body portion 15 extends from the top of the body portion 15 to a region adjacent the resilient web 25. A spindle 27, formed integrally with the body portion 15 of the locking device, extends substantially parallel to the direction of motion, during use, of the locking device 13. This spindle 27 receives a helical spring 29 within the recess 9 of the handle 3. The helical spring 29 sits on a shaped shoulder 31 within the recess 9 and biases the locking device 13 into its unlocked position (as shown in figure 1). The locking device 13 further includes a second flange 33 attached via a resilient support 35 to the body portion 15. During use, the second flange 33 engages a corner 37 formed in a wall of the recess 9, thereby dictating the unlocked position of the locking device 13. As can be seen from figure 2 of the drawings, when the locking device 13 has been depressed from its unlocked position shown in figure 1, the first flange 21, or detent, bears against the underside of a projection 39 extending out from the wall of the recess 9. The contact between the detent 21 and the projection 39 ensures that the locking device 13 remains in its locking position with the active portion 23 within the opening 11. This arrangement prevents rotation of the handle 3 about the pivot 5. To release the locking device 13, it is simply necessary to disengage the detent 21 from the projection 39. This is achieved by inserting a butterfly end 41 of the key 19 into the aperture 17 of the locking device 13. The butterfly end 41 of the key 19 is then rotated, by means of the head 43 of the key 19, when the butterfly end 41 abuts the top of the lower portion 24 of the locking device 13. Rotation of the butterfly end 41 causes the resilient web 25 to bend (as shown in chain line in figure 2), thereby separating the detent 21 and projection 39. As soon as disengagement occurs, the helical spring 29 forces the locking device 13 upwards into its unlocked position, as shown in figure 1. The key 19 can then be removed from the aperture 17 and the resilient web 25 reverts back to its relaxed position. If the vent handle is to be locked again, the locking device 13 needs only to be depressed, so that the detent 21 slides past the projection 39 and engages the underside thereof. This is facilitated by the angled bearing surfaces of the detent 21 and projection 39, as shown in the drawings. As will be appreciated from the foregoing, a locking device according to the invention is simple to use and cheap to manufacture, but sufficiently efficient and reliable to satisfy its functional requirements. With specific reference to the cost of manufacture, there is a fundamental saving in this regard, because the locking device 13 can be made as a one-piece moulding from plastics materials.

Claims: A locking device (13) adapted to be pressed, during use, into a locking position and released therefrom by means of a key (19), comprising a body portion (15), having an aperture (17) therein for receiving a key (19) during unlocking, an active portion (23) for effecting locking when the device (13) is depressed and a detent (21) retaining the device (13) in its locking position when depressed, characterised in that the detent (21) is attached to the body portion (15) by means of a resilient web (25), and in that interaction of the key (19) with the locking device (13) bends the resilient web (25), thereby de-activating the detent (21) and enabling the device (13) to be biased back into its unlocked position. A locking device as claimed in claim 1, further comprising means (27) for receiving a biasing means (29) which, when the detent (21) is de-activated, urges the device (13) back into its unlocked position. A locking device as claimed in claim 2, wherein the receiving means (27) is a spindle formed integrally with the body portion (15) for receiving a helical spring (29). A locking device as claimed in any preceding claim, wherein the detent (21) includes a first flange extending in a direction substantially perpendicular to the direction of motion, during use, of the device. A locking device as claimed in any preceding claim, wherein the active portion (23) and the detent (21) are formed integrally. A locking device as claimed in any preceding claim, further comprising means (23) for dictating the unlocked position of the device (13). A locking device as claimed in claim 6, wherein the dictating means (33) includes a second flange extending in a direction substantially perpendicular to the direction of motion, during use, of the device. A locking device as claimed in claim 7, wherein the dictating means (33) is attached via a resilient support (35) to the body portion (15). A locking device as claimed in any preceding claim, wherein the body portion (15) is substantially cylindrical. A locking device as claimed in any preceding claim, wherein the whole device (13) is manufactured as a one-piece plastics moulding. A vent locking mechanism (1) comprising a handle (3), a base (7) upon which the handle (3) is rotatably mounted and a locking device (13), the locking device (13) being adapted to the pressed, during use, into a locking position engaging the base (7), thereby preventing rotation of the handle (3), and released therefrom by means of a key (19), the locking device (13) comprising a body portion (15), having an aperture (17) therein for receiving a key (19) during unlocking, an active portion (23) for effecting locking when the device (13) is depressed and a detent (21) retaining the device (13) in its locking position when depressed, characterised in that the detent (21) is attached to the body portion (15) by means of a resilient web (25), and in that interaction of the key (19) with the locking device (13) bends the resilient web (25), thereby de-activating the detent (21) and enabling the device (13) to be biased back into its unlocked position. A vent locking mechanism as claimed in claim 11, wherein, when the locking device (13) is depressed, the active portion (23) enters a recess in the base (7) and the detent (21) interacts with a shaped part of the handle (3). A vent locking mechanism as claimed in claim 11 or claim 12, wherein the locking device (13) is accommodated within a recess (9) in the handle (3), together with a biasing means (29) for urging the locking device into its unlocked position.

Inventors: BAKER NEIL MARTIN, EMERSON BEN JOHN, MAYES JOHN, STRATFORD GRANT, VOWLES JOHN CHRISTOPHER, BAKER, NEIL MARTIN, EMERSON, BEN JOHN, MAYES, JOHN, STRATFORD, GRANT, VOWLES, JOHN CHRISTOPHER
Applicants: SECURISTYLE LTD, SECURISTYLE LIMITED
Application year: 1991
Main classification: E05B13
IPC codes: E05B35, E05B13, E05C19