GB2232191A - Door lock furniture - Google Patents

Abstract

Lock furniture comprising a door lock having a spring bolt operated by rotation of a follower and an elongate spindle of polygonal cross section engaged within a corresponding hole in the follower. Substantially to eliminate free play between the interengaging elements the spindle 1, at the portion thereof received within the hole in the follower, is split into two separate members 1a, 1b in longitudinal alignment and in overlapping contact with each other on transverse faces 7 each at an oblique angle to the longitudinal axis of the spindle. Means comprising inclined surfaces (10, 11) Fig. 4 engageable by retaining screws in the handles, or a grub screw (24) fitted axially in one of the members 20b, are operable to draw the two members 1a, 1b of the spindle longitudinally apart so that they slide over each other at their contacting transverse faces 7 and thus cause the spindle to expand into engagement with the wall of the hole in the follower. <IMAGE>

Description

LOCK FURNITURE This invention relates to lock furniture.

A conventional assembly of lock furniture comprises a door lock including a spring bolt operatively connected by a runner to a follower rotatably supported in the lock case. A spindle, usually square in cross section, is fitted in the door handles and passes through a hole of corresponding cross section in the follower to enable either handle, when turned, to operate the bolt.

A problem inherent in the conventional lock furniture is the existence of free play (lost motion) between pairs of interengaging elements of the assembly. Where each pair of elements in the assembly interact there are dimensional tolerances which give rise to the free play. The dimensional tolerances are frequently substantial due to the manufacturing processes employed for the various elements.For example: the lock follower is fitted into punched holes in the lock case with no bearing or washer, square spindle holes in the followers are broached and are generally inaccurate in size and shape, spindles are seldom exactly of the size and shape to make a transitional fit within the follower hole, the handles may be fixed to the spindle but the fixings do not take up tolerances between the handles and the spindle, the locks are generally fitted inaccurately in the door by carpenters who are not concerned to observe any tolerances.

In addition after many operations of the lock furniture causing wear of the various elements the tolerances between the elements increase. All the individual tolerances are transferred to the handles resulting in rattling and drooping of the handles when operated; drooping is especially noticeable, and is something that should be avoided, when lever handles are employed.

It is an object of the present invention to provide a construction of lock furniture in which free play between interengaging elements can be substantially eliminated.

Accordingly the present invention provides lock furniture comprising a door lock having a spring bolt operated by rotation of a follower, an elongate spindle of polygonal cross section engaged within a corresponding hole in the follower, wherein the spindle, at the portion thereof received within the hole in the follower, is split into two separate members in longitudinal alignment and in overlapping contact with each other on a transverse face at an obtuse angle to the longitudinal axis of the spindle, and means operable to draw the two members of the spindle longitudinally apart so that they slide over each other at their contacting transverse faces and thus cause the spindle to expand into engagement with the wall of the hole in the follower.

Two embodiments of the invention will now be described by way of example, reference being made to the accompanying drawings in which: Figure 1 is a partial view of one embodiment of lock furniture according to the present invention seen in vertical transverse section through the follower, Figure 2 is a cross section on the line A-A in Figure 1 Figure 3 is a cross section on the line B-B in Figure 1, Figure 4 is a cross section on the line C-C in Figure 3, Figure 5 is an exploded perspective view of the spindle, Figure 6 is an exploded perspective view of an alternative spindle used in another embodiment of the invention, and Figure 7 is an exploded perspective view similar to Figure 6 of a further alternative spindle used in yet another embodiment of the invention.

Referring to Figures 1 to 5 of the drawings, the embodiment of lock furniture according to the invention illustrated comprises a door lock having a spring bolt operated by rotation of a follower 5 rotatably supported in the lock case 4; the spring bolt and the other operating mechanism therefor including a runner operatively interconnecting the bolt and follower 5 are not shown and are conventional. The lock is fitted in a door 20 to the outer faces of which are mounted handles 3, only one of which is illustrated. The handles are typically lever handles.

A spindle 1 of polygonal cross section, illustrated as square, extends through a hole 6 of corresponding cross section in the follower 5 and the outer ends of the spindle 1 extend into the handles 3.

The spindle 1 comprises two separate, longitudinally aligned members la and Ib which overlap each other within the hole 6 in the follower where they are in contact with each other at transverse faces 7.

The end face 8 of each member la, Ib is normal to the longitudinal axis 9 of the elongate spindle 1 (i.e. the axis of the longitudinally aligned members la and lb) and face 7 extends longitudinally therefrom at an obtuse angle a to the longitudinal axis 9 to terminate at a second face 18 normal to the longitudinal axis.

The face 7 extends across the spindle between opposite corners thereof (see Figure 2), thus generally across a diagonal. The outer corners of the face 7 adjoining the end face 8 of each member may be bevelled as shown at 13 in Figure 5 to aid assembly.

The outer ends of the members la and Ib which are received within the handles 3 are formed each with a wedging surface 10 the plane of which is also at an obtuse angle ss to the axis 9 and an adjoining angled bevel face 11. A knurled cup point set screw 2 is fitted in each handle 3 and engages the spindle at the wedging surface 10 and the bevel face 11, see particularly Figure 3.

On tightening of the grub screw 2 in the lever, the inward movement of the screw against the wedging surface 10, assisted by the rotation of the serrated base of the screw against the angled bevel face 11, will draw the spindle member away from the lock and into the handle. When the grub screws 2 in both handles 3 are tightened the two spindle members la and lb will be drawn longitudinally apart, sliding against each other over the contacting faces 7. Due to the angle of the faces 7, the spindle members la and Ib will be forced transversely apart within the hole 6 in the follower 5, the result being that the spindle 1 will expand within the follower 5 into firm engagement with the wall of the hole 6. In this way free play between the spindle 1 and the follower 5 on the one hand and between the spindle 1 and the handles 3 on the other will be substantially eliminated.Furthermore the set screws 2 can be re-tightened at any time as necessary to take up any wear which develops in any of the elements aforesaid.

One of the spindle members la may be provided on opposite corners with ears 12 which will not pass through the hole 6 in the follower 5; this avoids having to tighten the grub screws 2 simultaneously since if the grub screw 2 fitted in the handle 3 over the member lb is first tightened alone, the ears 12 prevent the member la from being drawn through the follower 5. Thereafter the grub screw 2 fitted to the other handle can of course be tightened as needed to prevent looseness in the assembly. The ears 12 also assist assembly by locating the spindle longitudinally with respect to the follower.

Figure 6 illustrates an alternative spindle 20 used in a second embodiment of the invention. The spindle 20 may be used with handles 3 as in the embodiment of Figures 1 to 5, or as a "floating" spindle with handles which can be fixed to it in a variety of ways as known per se or with handles which are fixed independently of the spindle The spindle 20 comprises two separate, longitudinally aligned members 20a and 20b which are the same as the members la and ib previously described except that the member 20b is formed with a through bore 22 extending inwardly from the outer end face 21 the entire length of the spindle member lb. The bore is continued across the transverse face 7 of the member 20a as a channel 23, extending from the end face 8 to the face 18 of the member 20a. At least the inner end of the bore 22 in the member 20b is internally threaded, and received therein is a correspondingly threaded grub screw 24 which is accessible from the outer end face 21.

Assembly of lock furniture incorporating the spindle 20 proceeds by locating the spindle members 20a and 20b, overlapped at their transverse faces 7, within the hole 6 in the lock follower. Assembly of the members 20a and 20b is facilitated by bevelling the edge between faces 7 and 8 as shown at 14. A suitable tool is then introduced into the bore 22 from the end face 21 of the member 20b, and grub screw 24 is rotated to move inwardly until its base abuts the face 18 of the member 20a. Continued rotation of the grub screw 24 forces the members 20a and 20b longitudinally apart so that they slide over each other at their contacting faces 7 and will be caused to expand within the lock follower into firm engagement with the wall of the hole 6.The ears 12 act as stops to position the members 20a and 20b so that their contacting slide faces 7 are properly located within the hole 6 in the lock follower.

Finally, after the spindle 20 has been fixed within the lock follower as described, the handles are fitted over the ends of the spindle and fixed according to their type to complete the installation.

When handles provided with grub screws are fitted the grub screws can merely be tightened against the spindle members or, if the latter are also provided (as shown) with the aforesaid surfaces 10 and 11, then the spindle 20 can be used in full substitution for the spindle 1.

Figure 7 shows a further alternative spindle 30 which is intended for use as a floating spindle and is designed for the attachment of handles by means of a standard screw extending through a transverse bore in the handle and retained in conventional manner by screw-threaded engagement with the spindle.

The spindle 30 is identical with spindle 20 of Figure 6 except that the surfaces 10 and 11 are not provided and the portion of each spindle member 30a, 30b which extends into the handle is of full polygonal cross-section throughout. Each such portion is provided with a transverse slot 31 extending between opposite faces thereof. Fitted firmly within each slot 31 is an infill member or insert 32 of a hard resiliently deformable material such as a hard fibre material e.g. "Tansorite". The insert 32 fitted to at least the spindle member 30b has a longitudinally extending hole therethrough aligned with the bore 22 to allow access to the grub screw 24.

Assembly of the lock furniture incorporating the spindle 30 proceeds by locating the spindle members 30a and 30b, overlapped at their transverse faces 7, within the hole 6 in the lock follower, and tightening the grub screw 24 to expand the spindle members within the follower as described above in connection with Figure 6. Then, the handles are fitted over the respective spindle members 20a and 20b.

As stated, each handle has a transverse bore for a retaining screw. The bore is positioned over the insert 32 and a retaining screw, typically a selftapping screw (not shown) is inserted and is driven home, cutting a thread in the insert 32 in the process.

The longitudinal extent of the slots 31, and hence of the inserts 32, allow for a range of fitting positions for the handles and thus enable the lock furniture to accommodate doors of a variety of thicknesses without modification and the need for packing members while retaining the benefits of substantial elimination of free play.

Claims (9)

1. Lock furniture comprising a door lock having a spring bolt operated by rotation of a follower, an elongate spindle of polygonal cross section engaged within a corresponding hole in the follower, wherein the spindle, at the portion thereof received within the hole in the follower, is split into two separate members in longitudinal alignment and in overlapping contact with each other on a transverse face at an obtuse angle to the longitudinal axis of the spindle, and means operable to draw the two members of the spindle longitudinally apart so that they slide over each other at their contacting transverse faces and thus cause the spindle to expand into engagement with the wall of the hole in the follower.

2. Lock furniture according to Claim 1, wherein the spindle is of square cross section and the transverse face of each member extends across a diagonal.

3. Lock furniture according to Claim 2, wherein each transverse face extends longitudinally between planar faces normal to the axis of the spindle.

4. Lock furniture according to any one of the preceding claims, including a pair of handles fitted one over each outer end of the two spindle members, and wherein the means for drawing the spindle members longitudinally apart includes a wedging surface formed on each member adjacent its outer end received within the handle and at an obtuse angle to the said axis, and a set screw is provided in each handle and contacting the wedging surface so that on tightening of the set screws against the wedging surfaces the two members of the spindle are drawn longitudinally apart and slide over each other at their contacting transverse faces thus causing the spindle to expand into engagement with the wall of the hole in the follower.

5. Lock furniture according to Claim 4 including a bevelled face adjacent each wedging surface, and wherein the set screws are knurled cup point screws engaging the bevelled faces by their serrated ends.

6. Lock furniture according to either of Claims 1 and 2, wherein the means for drawing the two spindle members longitudinally apart includes a longitudinal bore in one of the spindle members and a grub screw threadedly received within the bore whereby on rotation of the grub screw in a direction to cause the grub screw to travel inwardly of the bore the head thereof abuts against the other spindle member and forces the spindle members longitudinally apart so that they slide over each other at their contacting transverse faces and thus cause the spindle to expand into engagement with the wall of the hole in the follower.

7. Lock furniture according to Claim 6, wherein the portion of each spindle member receivable within a handle is provided with an insert capable of having a handle-retaining screw driven thereinto.

8. Lock furniture according to Claim 7, wherein the insert is a hard resiliently deformable material into which a self-tapping screw can cut a thread.

9. Lock furniture substantially as hereinbefore described with reference to the accompanying drawings.