This invention relates to deadbolt assemblies of the kind used to releasably secure a door, for example, in a closed position by moving a deadbolt in a direction substantially parallel to an adjacent edge of the door.
The deadbolt can be slidably mounted in a housing having two vertically spaced recesses for receiving respective parts of a strike. The deadbolt has two parts each of which is arranged to extend across a respective one of the housing recesses when the deadbolt is in its operative position. In the inoperative position, said parts of the deadbolt are withdrawn into the housing to leave the housing recesses clear for movement of said parts of the strike into and out of the housing recesses. Each of said parts of the strike has an aperture which is able to receive a respective one of said parts of the deadbolt when the strike parts are properly located in the housing recesses.
A deadbolt assembly usually includes inside and outside actuators. The outside actuator is typically a key operated lock, whereas the inside actuator can be either a manually operable turn knob or a key operated cylinder. If a turn knob is employed the deadbolt assembly may also include a security feature which is selectively operable to hold the turn knob against rotation or otherwise render it ineffective for operation of the deadbolt from the inside of the door.
A mechanism through which the actuators drive the deadbolt between its operative and inoperative positions is known from FR-A 2 286 933, which is acknowledged by the preamble of the present independent claim, and which discloses inter alia a deadbolt having a notch along one side forming a non-circular opening having two co-operating edges with which a drive pin can engage to cause linear movement of the deadbolt, but the drive pin escapes from the notch when the deadbolt is in the operative and inoperative positions and thus does not remain in engagement with either of said two co-operating edges of the notch.
It is an object of the present invention to provide an assembly of the foregoing kind in which the mechanism is more positive in operation than prior mechanism of the same kind and is less complex and therefore relatively inexpensive.
In accordance with the present invention, a deadbolt assembly comprises a housing, a deadbolt mounted on said housing for linear movement relative thereto between operative and inoperative positions, an actuator mounted on said housing, a drive plate rotatably mounted on said housing and being connected to said actuator so as to rotate in response to operation of said actuator, and a drive pin fixed to said drive plate so as to move therewith and being located radially outwards from the axis of said plate rotation, said deadbolt having a non-circular opening and said drive pin engaging against a respective one of two co-operating edges of said opening to cause said linear movement of said deadbolt in each of two opposite directions as said drive plate is rotated in opposite directions, characterised in that said opening is surrounded by said deadbolt and is substantially triangular having one edge which extends substantially in the direction of said linear movement and two further edges which converge away from said one edge with said converging edges forming said co-operating edges, a junction being provided between each adjacent two of said edges, the junction between each said converging edge and said one edge being arranged to provide a seating surface for said drive pin when said deadbolt is in said operative position and said inoperative position so as to resist movement of said drive pin out of the respective junction, at least in one direction.
Assuming the inside actuator is a turn knob, it may be connected to the drive plate in the manner described in our copending EP-A 0 229 514.
An embodiment of the invention is described in detail in the following passages of the specification which refer to the accompanying drawings in which:
The invention is applicable to deadbolt assemblies of various kinds, and Fig. 1 shows one such assembly. The arrangement of Fig. 1 includes a deadbolt housing 1 which is secured to a door 2 and a strike 3 which is secured to the door jamb 4. Two recesses 5 and 6 are provided in a projecting end 7 of the housing 1 and each is adapted to receive a respective one of the bars 8 and 9 of the strike 3. The deadbolt 10 (Fig. 2) has two parts 11 and 12, each of which extends across a respective one of the recesses 5 and 6 when the deadbolt 10 is in its operative position.
An assembly of the foregoing kind includes an inside actuator 13 and an outside actuator 14, both of which are shown in Fig. 2. The outside actuator 14 of the arrangement shown is a key operated lock, whereas the inside actuator 13 is in the form of a manually operable turn knob. The turn knob 13 is connected to the deadbolt 10 through a drive connection which includes a rotatable plate 15 and a drive pin 16 fixed to the plate 15 so as to move therewith and being located radially outwards from the axis of rotation of the plate 15.
In the arrangement shown, the drive plate 15 is in the form of a disc and a hole 17 is formed through the centre of the plate 15. That hole 17 enables a connection to be effected between the outside actuator 14 and another key operated lock 18 which, in the construction shown, is mounted in the turn knob 13 to enable the deadbolt to be locked from the inside of the door.
It is preferred that the rotational movement of the plate 15 is guided by a guide plate 19 which is fixed to the housing 1. That plate 19 may have an arcuate slot 20 formed therein as shown, and the drive plate 15 and guide plate 19 are arranged in face to face relationship with the pin 16 extending through the guide slot 20. An end portion 21 of the pin 16 projects beyond the guide plate 19 for engagement with the deadbolt 10 or a member secured thereto. The arcuate slot 20 is preferably arranged so that its opposite ends 22 and 23 are located on a line extending substantially parallel to the path of movement of the deadbolt 10, and that line may substantially intersect with the axis of rotation of the plate 15.
The deadbolt 10 shown includes two cylindrical parts II and 12 arranged substantially coaxial and arranged in axially spaced relationship. As shown, those parts II and 12 are interconnected through a carrier plate 24 which is located at the side of the guide plate 19 remote from the drive plate 15. In the preferred form shown, the carrier plate 24 is pressed or stamped from a metal plate such as steel, and each deadbolt part II and 12 may be also formed from steel or a similar hard metal. Such deadbolt parts and their carriers have traditionally been cast from zinc, for example, and consequently have been relatively weak and susceptible to breakage in the event of attempted forced actuation. A steel or similar hard metal arrangement as provided in the present construction is much more resistant to damage and is therefore more secure than prior constructions.
According to the particular construction shown, the main body of the carrier plate 24 is in substantially face to face relationship with the guide plate 19 and cooperates with that plate 19 or the housing I in such a way as to be held to a line of movement which extends substantially parallel to the axis of the deadbolt parts 11 and 12. That may be achieved by means of two guide pins 25 secured to the carrier plate 24 and slidably located in respective guide slots 26 formed through the guide plate 19. The guide pins 25 extend outwards from a face of the carrier plate 24 and are located in spaced relationship along a line extending substantially parallel to the axis of the deadbolt parts II and 12. Each of the cooperating slots 26 of the guide plate 19 extends in substantially the same direction as that line.
Each deadbolt part II and 12 is preferably secured to a respective arm 27 projecting laterally outwardly from an end of the body of the carrier plate 24. Those arms 27 are preferably integral with the body of the plate 24 and in the arrangement shown are bent from upper and lower ends respectively of a backwardly turned flange 28 of the carrier plate 24. Each arm 27 may be strengthened against deflection by being pressed, stamped or otherwise formed to have a longitudinally extending rib 29 therealong. The deadbolt parts II and 12 may be secured to their respective arms 27 by riveting or other appropriate procedure.
The drive pin 16 engages with the carrier plate 24 in such a way that the plate 24 moves as required in response to rotation of the drive plate 15. In the preferred arrangement shown, that engagement is achieved by having the pin 16 located within a cam opening 30 which is formed through the carrier plate 24. That opening 30 may be of triangular shape as shown, having an edge 31 extending upwards in the direction of the guide slots 26 and the other two edges 32 and 33 converge away from the upright edge 31 generally in a direction towards the deadbolt parts II and 12.
When the deadbolt 10 is in the inoperative position as shown in Figures I and 3, the drive pin 16 is located at the bottom end 23 of the arcuate slot 20 of the guide plate 19 and also at the lower end 34 of the upright edge 31 of the cam opening 30. If the plate 15 is then rotated to move the pin 16 along the arcuate slot 20, the pin 16 will also naturally travel towards the apex 35 of the converging edges 32 and 33 of the cam opening 30. At some stage (Figure 4) in that movement the pin 16 engages the upper edge 33 of the cam opening 30 and thereafter pushes the carrier plate 24 upwards. Such upward movement of the carrier plate 24 moves the deadbolt parts II and 12 towards the operative position (Figure 5) and that position is reached at or near the time when the pin 16 reaches the upper end 22 of the arcuate guide slot 20. At that time, the pin 16 will also be at the upper end 36 of the upright edge 31 of the cam opening 30.
As will be seen from Figures 2 to 5, the junction between each of the edges 31, 32 and 33 are preferably of arcuate form. It is further preferred that those junctions 34, 35 and 36 are arranged so that each provides a seating surface for the pin 16 such that movement of the pin 16 out of any one of the junctions 34, 35 and 36 is resisted. That is, each junction 34, 35 and 36 in effect forms a shallow recess in which the pin 16 seats or nests to an extent such that a force must be applied to overcome the restraining influence against movement of the pin 16 out of that recess.
The foregoing arrangement has the particular advantage that the pin 16 is positively located in the position at which the deadbolt 10 is operative. Also, the arrangement is such that the pin 16 positively holds the carrier plate 24 against forced movement into the inoperative position of the deadbolt 10. In particular, such movement of the carrier plate 24 can only be initiated by rotation of the plate 15 and that cannot be effected by applying a downward force to the deadbolt parts II and 12 or the arms 27 on which those parts II and 12 are mounted.
If desired, a spring 37 may act between the pin 16 and the carrier plate 24 so as to urge the pin 16 towards the upright edge 31 of the cam opening 30 and thereby ensure that the pin 16 normally locates in one of its extreme positions.
A further advantage of the improved deadlock- ing mechanism as described is that it permits the housing I to be fixed to a door 2 in a more secure manner than was previously possible. In the preferred arrangement shown, a mounting plate 38 of steel or other suitable metal is secured in any appropriate manner in face to face relationship with the inside surface of a door 2. An outwardly projecting flange 39 and 45 respectively is provided at each of the upright sides of that plate 38 and at least one fixing screw hole 40 is provided through the flange 39. Preferably, there are two such holes 40 in the flange 39 and they are spaced vertically apart. It is further preferred that the holes 40 in the flange 39 are screw threaded holes to cooperate with the thread of the fixing screws 41.
The mounting plate 38 is dimensioned so as to fit within the open back of the hollow housing I (Figure 2) and in the assembled condition the front flange 39 preferably abuts against or lies close to the inner surface of an outer side wall 42 of the housing I. That outer side wall 42 is the wall closest to the front edge of the door 2 and is provided with a pair of holes 43 which align with the holes 40 of the front flange 39. It is preferred that the rear flange 45 locates against or close to the inner side wall 44 of the housing I.
It is preferred that the flange 45 is provided with two slots 46 which are adapted to receive respective lugs 47 provided on an edge of the guide plate 19. The plate 19 is fixed to the housing I by fastening screws 48 and consequently interaction between the lugs 47 and the slots 46 serve to assist in the firm retention of the housing I on the mounting plate 38.
The foregoing arrangement is such that the housing I is firmly secured to the door 2 and in such a manner that the fixing screws 41 are concealed from view and tampering while the door 2 is in a closed position.
The security of the assembly can be further improved by forming the strike 3 of sheet metal such as steel rather than die cast zinc as in the past. In the arrangement shown, the strike 3 is formed from a rectangular section of metal plate (Figure 6) having a rectangular opening 49 therethrough so as to form two laterally spaced bars 8 and 9 which extend in the longitudinal direction of the plate section. As shown, the width of those bars 8 and 9 is reduced by removing an adjacent edge portion of the plate. Each of the opposite end portions 50 and 51 of the plate section can have a plurality of holes 52 therethrough for receiving fastening screws.
A plate section as described can be formed into an effective strike by bending that section intermediate the length of the bars 8 and 9 so that each bar 8 and 9 adopts a substantially U shape as shown in Figures I and 7. At least one end portion 50 of the plate section is bent along a line extending transverse to the bars 8 and 9 so as to form a mounting flange 53 which is disposed in opposed relationship to the base of the U-shaped bars 8 and 9. The other end portion 51 may be similarly bent in which event the two flanges 53 and 54 overlie one another as shown in Figure I. Alternatively, as shown in Figure 7, the end portion 51 may be left to form a mounting flange 54 which is arranged substantially at right angles to the flange 53.
In a variation of the construction last described, sections of plate (not shown) between and outside of the bars 8 and 9 may project at right angles to the flange 54 so as to overlie the flange 53. Such an arrangement improves the security of the strike 3 because fastening screws can be passed through those plate sections and the underlying flange 53.
The strike 3 described above can be secured to a door jamb 4 by means of the mounting flanges 53 and 54 and in a position such that the U-shaped bars 8 and 9 are able to enter into respective front end recesses 5 and 6 of the deadbolt housing 1. The space 55 enclosed by each bar 8 and 9 thus forms an opening for receiving a respective part 11 and 12 of the deadbolt 10.
It will be appreciated that a strike 3 as described has substantially greater strength than prior die cast strikes and is therefore much more resistant to breakage. That feature when combined with other features as previously described in this specification results in an exceptionally secure deadbolt assembly.