GB2063981A - A Double-lock Assembly for a Door - Google Patents

Abstract

A double-lock assembly for a door, comprising a frame (1) having an opening (2), a channel shaped dead bolt (5) accommodated in said frame (1) and movable toward and away from said opening (2), a latch bolt (4) slidably received in said dead bolt (5), a dead bolt drive member (13) and a latch bolt drive member (17) which are provided coaxially with each other, and first and second intermediate members (10, 8) through which said dead bolt and said latch bolt are operated by said dead bolt drive member and said latch bolt drive member, respectively. <IMAGE>

Description

SPECIFICATION A Double-lock Assembly For a Door The present invention relates to a double-lock assembly for use with a door. A dead bolt and a latch bolt in a lock of the type described have heretofore been installed in parallel relation, and such a conventional lock tends to be bulky.

Therefore, an object of the present invention is to provide a double-lock assembly which is small in size and light in weight compared to known double-lock assemblies.

According to the invention, there is provided a double-lock assembly for a door, comprising a frame having an opening, a channel-shaped dead bolt accommodated in said frame and movable towards and away from said opening, a latch bolt slidably received in said dead bolt, a dead bolt drive member and a latch bolt member which are provided coaxially with each other, and first and second intermediate members through which said dead bolt and said latch bolt are operated by said dead bolt drive member and said latch bolt drive member, respectively.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 shows in perspective a double-lock according to the present invention with part of its frame cut away; Fig. 2 is a perspective view of an internal structure of the double-lock with the frame entirely removed: Fig. 3 is a plan chiefly showing a latch bolt drive mechanism; Fig. 4 is common to Fig. 3 except that the latch bolt is in an unlatching position; Fig. 5 is a plan chiefly showing a dead bolt drive mechanism; and Fig. 6 is similar to Fig. 5 but illustrated the dead bolt in a latching position.

A lock assembly of the invention includes a channel-shaped frame 1 having an opening 2 at one longitudinal end and carrying a mounting plate 3 integrally therewith. A latch bolt 4 is slidably received in a channel-shaped dead bolt 5 which is in turn slidable within the frame 1. These bolts 4 and 5 are both movable into and out of the frame through the opening 2.

Internally threaded posts 6 and 6' extend from and perpendicularly to a bottom wall 1 a of the frame to facilitate mounting of a closure member (not shown) to the frame. A flat spring seat 1 b protrudes from the bottom wall 1 a of the frame to the front end of the front post 6. A latch bolt 4 is constantly biased outwardly of the frame 1 by a first coil spring 7 whose opposite ends bear on the spring seat 1 b and latch bolt 4 respectively.

The latch bolt 4 has at its rear end two tabs 4a which are movably engaged in guide recesses 1 d provided in side walls 1 c of the frame, thus protruding a constant amount beyond opposite margins of the opening 2.

Also accommodated slidably in the frame 1 is a channel shaped intermediate member 8 for driving the latch bolt. A second coil spring 9 is anchored at one end to a flat spring seat 8b extending from the bottom 8a of the intermediate member 8 and at the other end to a spring seat 1 e extending from the bottom 1 a of the frame.

Therefore, the intermediate member 8 is normally biased into engagement with the post 6 by the action of the coil spring 9. In this situation, guide recesses 8d in opposite side walls 8c of the intermediate member 8 are aligned with the recesses 1 d of the frame so that the tabs 4a of the latch bolt are kept engaged with both of the aligned ends of the recesses 1 d and 8d.

The side walls 8c alone of the member 8 extend rearwardly along the side walls 1 c of the frame and have, at the extensions, formed recesses 8e.

Riveted to the inner end of the dead bolt 5 as at 11 is a further intermediate member 10 which extends rearwardly along the inner surface of one of the side walls 8c of the intermediate member 8. This member 10 integral with the dead bolt is provided with a slot 1 Oa, and a pin 1 Ob for retaining a leaf spring 12.

The reference numeral 13 designates a generally cylindrical dead bolt drive member rotatably mounted to the frame 1 and having a central bore 1 3a. Engaged in this bore 1 3a is a rectangular lever 1 6 which may be rotated by a thumb piece (not shown) or a cylindrical latch 1 5 incorporated in each of knobs 14 and 14' or handles (not shown) at respective opposite sides of a door. The drive member 13 has on its outer periphery a drive arm 1 3b which is engaged in the slot 1 Oa of the member 10. Further provided on the outer periphery of the drive member 1 3 is a projection 1 3c aligned circumferentially with the drive arm 1 3b and engaged with the free end of the leaf spring 12.

A disc 1 7 for driving the latch bolt is rotatably coupled over the dead bolt drive member 13 at its central opening 1 7a. Ears or shoulders 1 7b protruding from the disc 17 are respectively engaged in the recesses 8e of the intermediate member 8.

The disc 1 7 also has an arcuate slot 1 7c in which an arcuate lever 1 8 is movable engaged.

The lever 1 8 is connected with and movable integrally with the knob 14 or 14'.

The double lock having the above construction operates as follows. The latch bolt 4 of the lock assembly remains in an extended position under the action of the spring 7 while the door is in an open position. When the door is moved from the open position to a closed one, the latch bolt 4 is brought into engagement with a metal fixture on a pillar or the like and thereby caused to retract while compressing the coil spring 7. Upon full closure of the door, the latch bolt 4 again extends by the returning action of the coil spring 7, but now extends into the metal fixture.

To open the door from the closed position, the knob 14 or 14' is manipulated in either direction causing its associated arcuate lever 1 8 to rotate the disc 17. Then either one of the shoulders 1 7b of the disc urges the intermediate member 8 rearwardly while compressing the second coil spring 9. As a result, the latch bolt 4 is pulled rearwardly to a retracted position by the intermediate member 8 through the interengaging recesses 8d and tabs 4a while compressing the coil spring 7.

Upon release of the knob 14 or 14', the intermediate member 8 restores the advanced position with the aid of the coil spring 9 thereby moving the disc 17 and knob back to their usual positions. Meanwhile, the latch bolt 4 now free from the restraint offered by the member 8 is allowed to advance to the extended position by the coil spring 7.

When the rectangular lever 16 is turned through the latch 1 5 or the like while the door is in the closed position, the dead bolt drive member 13 turning in the same direction advances the member 10 with its drive arm 1 3b engaged in the recess 1 Oa, whereby the dead bolt 5 is brought to a projected or latching position. A rotation of the drive member 13 in the opposite direction will cause the dead bolt 5 and member 10 to retract to an unlatching or retracted position. It will be noted that the leaf spring 12 holds the dead bolt 5 in the latching or unlatching position by preventing the rotation of the drive member 13 by way of projection 1 3c.

Thus the double-lock assembly according to the present invention includes a channel shaped dead bolt and a latch bolt slidably nested inside the dead bolt. It will thus be appreciated that this kind of design markedly reduces the size and weight of a double-lock of the type described and facilitates ready mounting of the assembly to a door. Additionally, the channel shape offers a sufficient durability to the dead bolt.

Claims (14)

Claims

1. A double-lock assembly for a door, comprising a frame having an opening, a channel shaped dead bolt accommodated in said frame and movable towards and away from said opening, a latch bolt slidably received in said dead bolt, a dead bolt drive member and a latch bolt drive member which are provided coaxially with each other, and first and second intermediate members through which said dead bolt and said latch bolt are operated by said dead bolt drive member and said latch bolt drive member, respectively.

2. An assembly as claimed in claim 1, wherein said dead bolt drive member is rotatably mounted in said frame and is operable at either of two knobs or handles disposed at respective opposite sides of the door, in use.

3. An assembly as claimed in claim 2, wherein said dead bolt drive member has a lever projecting from it, which lever can be rotated thereby to rotate said dead bolt drive member by means of a thumb piece or a latch incorporated in each of said knobs.

4. An assembly as claimed in any one of claims 1 to 3, wherein said dead bolt drive member has a drive arm on its outer periphery to engage said first intermediate member.

5. An assembly as claimed in claim 4, wherein said first intermediate member has a surface with a slot therein, in which said drive arm engages so as to move the first intermediate member towards or away from said opening, as said dead bolt drive member is rotated in one direction or the other.

6. An assembly as claimed in claim 5 wherein said dead bolt drive member has a projection on its outer periphery which engages a leaf spring which thereby holds said dead bolt drive member in either its dead bolt retracted or dead bolt extended position.

7. An assembly as claimed in any one of claims 1 to 6 wherein said dead bolt is directly secured to said first intermediate member.

8. An assembly as claimed in any one of claims 2 to 7 wherein the latch bolt drive member is a disc rotatably coupled over the dead bolt drive member so as to be coaxial therewith.

9. An assembly as claimed in claim 8, wherein the disc has an arcuate slot therein, in which a lever movable together with said knobs or handles, in use, is movably engaged, so that rotation of one of said knobs or handles, in use, causes rotation of said disc.

10. An assembly as claimed in claim 9, wherein said disc has a pair of ears projecting therefrom, said ears engaging in respective recesses formed in the second intermediate member, so that rotation of said disc causes movement of said second intermediate member away from said opening.

1 An assembly as claimed in claim 10 wherein said latch bolt is provided with a pair of tabs engaging in respective further recesses in said second intermediate member, so that said movement of the second intermediate member away from said opening pulls said latch bolt towards its retracted position.

12. An assembly as claimed in claim 11 wherein movement of second intermediate member away from said opening occurs against the force of biasing means disposed between part of said second intermediate means and a stop formed on said frame, and movement of said latch bolt towards its retracted position also occurs against the force of biasing means, disposed between a further stop on said frame and part of said latch bolt.

13. An assembly as claimed in any one of claims 1 to 12, wherein said second intermediate member is channel shaped.

14. A double-lock assembly for a door, substantially as hereinbefore described with reference to and as shown in the accompanying drawings.