GB2099065A

GB2099065A - Combination lock dials

Info

Publication number: GB2099065A
Application number: GB8136631A
Authority: GB
Original assignee: Kidde Inc
Current assignee: Kidde Inc
Priority date: 1981-05-19
Filing date: 1981-12-04
Publication date: 1982-12-01
Also published as: AU7789581A; DE3147395A1; IT1145477B; IT8149989A0

Abstract

A rotary dial and dial spring assembly for a combination lock includes a dial of polygonal cross section defining contiguous dial indicia surfaces 24 on the periphery of the dial. The spring has a spring arm 28 with first and second portions b, c that engage adjacent dial indicia surfaces face-to-face to provide positive step-by-step rotation of the dial between successive indicia settings. One of the dial indicium surfaces has a protrusion 26 which cooperates with an opening 30 in the spring arm to allow unimpeded step- by-step rotation of the dial in one direction but prevents rotation of the dial in the other direction beyond a point at which the protrusion engages a stop surface e on the spring. <IMAGE>

Description

SPECIFICATION Improvements relating to rotary dials and dial springs for use in combination locks and the like Background of the Invention The invention relates to rotary dials and dial springs for use in combination locks and the like, the dials being of the type which carry a series of combination indicia spaced around the dial periphery.

Dials of the type referred to may be used in locks having diverse forms of locking actions, for example, pivotal bolt-type locks or sliding latchtype locks. Generally, the dials are rotated manually to move the lock between oncombination and off-combination conditions, which are dependent upon the relative rotational positions of the dials. Commonly, in combination locks, a plurality of dials are carried in axially adjacent positions on a shaft, and they may be associated with internal sleeves to which they are normally rotationally coupled. To change the combination of the lock, the dials and sleeves may be uncoupled by effecting relative axial movement therebetween.

One form of rotary dial in common use is of generally circular cross section, the periphery of which is divided into segments for the respective indicia, with detents in the form of V-shaped notches being provided between the respective segments. The detents cooperate with a dial spring having an arm adapted to engage the detents to provide positive step-by-step rotation of the dial between successive indicia settings.

One of the detents may be asymmetrical, with one steeply angled surface, so that the dial spring arm can only be disengaged from this detent by rotation of the dial in one direction. (The detents are substantially symmetrical with relatively shallow surfaces allowing disengagement of the spring arm by rotation of the dial in either direction.) The asymmetrical detent may be used for providing a "zero-stop" feature, by which the on-combination setting of the lock may be established by a user entirely by feel, by rotating the dials until, in each case, the asymmetrical detent prevents further rotation.

In certain respects, dials as described above have not been found in practice to be entirely satisfactory. For example, the presence of the detents between the respective indicia segments limits the height of the indicia for a fixed dial diameter. This is of particular importance in smallsize dials where visibility of the indicia is a factor.

To improve indicia visibility, a practice has been made of inking the indicia, but this increases costs. Another problem is the criticality of the detent configurations in providing positive stepby-step action. The presence of burrs or foreign matter in the detents mitigates against consistent operation, and inaccuracies in detent formation may lead to dials having to be rejected.

Additionally, it may be possible to force a spring arm out of the asymmetrical detent, by forced rotation of a dial in the wrong direction, permanently damaging the spring.

The present invention provides improved dials and dial springs for use in combination locks and the like.

Summary of the Invention In one of its aspects, the invention provides a rotary dial and dial spring assembly for use in a combination lock and the like, wherein the dial has a substantially polygonal cross section defining contiguous indicia surfaces around the periphery of the dial, and the spring has a dial-engaging portion for providing positive step-by-step indexing of the dial between successive indicia settings by resilient face-to-face engagement of said dial-engaging portion of the spring with successive indicia surfaces of the dial.

In another of its aspects, the invention provides a rotary dial and dial spring assembly for use in a combination lock and the like, wherein the dial includes a protrusion and the spring, which is adapted to engage the dial and provide positive step-by-step indexing of the dial, includes a stop surface that forms a stop for said protrusion when the dial is rotated in one direction, preventing further rotation of the dial in said one direction, said protrusion and said surface being ineffective to impede step-by-step rotation of the dial in the opposite direction.

In still another aspect, the invention provides a dial spring for use in a combination lock and the like, in conjunction with a dial of substantially polygonal cross section defining contiguous indicia surfaces disposed around the dial periphery, the spring including a spring arm having a first dial-engaging portion, and a second dialengaging portion extending from the first portion, said portions defining an angle therebetween conforming to the included angle between a pair of adjacent indicia surfaces of the dial, to enable said portions of the arm to engage adjacent indicia surfaces of the dial face-to-face.

Additional features of the invention will become evident from the following description and claims, taken in conjunction with the accompanying drawings.

Brief Description of the Drawings Figure 1 is an exploded perspective view of parts of a combination lock including, in accordance with the invention, a plurality of rotary dials and an associated dial spring unit, and Figure 2 is an end view, partly in section, of one of the dials and a portion of the spring unit, illustrating the cooperation therebetween.

Description of the Preferred Embodiment As shown in the drawings, a plurality of rotary dials 10 are mounted in axially adjacent relationship on a shaft 12, in a combination lock casing. The lock casing includes a faceplate 1 4 with openings 16, through which portions of the dials project for manual manipulation thereof, and a baseplate 1 8 on which is positioned a dial spring unit 20.

It is understood that the lock may be of any conventional type using rotary dials. For example, the lock may be of a type in which the locking action is obtained by a pivotal bolt, under the control of the dials, as shown, for example, in U.S.

Patent No. 4,100,775. Alternatively, the lock may be of the type in which the locking action is obtained by a sliding latch, movement of which is controlled by the dial, as shown, for example, in U.S. Patent No. 3,416,338.

The dials may be made of metal or a suitable synthetic material and may have internal teeth 22 by which they are coupled with sleeves 11, only one of which is shown, for mutual rotation on shaft 1 2. Provision may be made for axial movement of the sleeves relative to the dials to uncouple the respective dials and sleeves for combination-changing purposes, in known manner.

Each of the dials has a polygonal cross section defining substantially flat contiguous indicia surfaces 24 around the periphery of the dial, each indicium surface being inscribed or otherwise provided with a distinctive combination indicium.

In general, as in the illustrated embodiment, there may be ten indicium surfaces, numbered 0--9, respectively, but the number of surfaces and the form of the indicium is not critical to the invention.

One of the indicia surfaces of each dial may include a cylindrical protrusion 26, for cooperation with the dial spring, as will be described.

Conveniently, the protrusion may, in each case, be provided on the indicia surfaces having the number 5 indicia.

Dial spring unit 20 may be formed from a single spring plate from which separate arms 28 are struck for each dial. (Alternatively, separate, single-arm springs may be used for the respective dials.) In the illustrated embodiment, the spring unit includes planar base portions 21 and a side portion 23. In use, the base portions are situated on the baseplate of a lock, and the side portion may engage a side wall of the lock casing (not shown).

Each arm 28 has a connecting portion a extending from the base of the side wall portion, a first flat dial-engaging portion b extending from the connector portion, a second flat dial-engaging portion c extending from the first flat portion, and a terminal portion d. The angle between portions b and c conforms substantially with the included angle between a pair of adjacent dial surfaces 24, and terminal portion d is bent to extend outwardly away from the dial. Each arm 28 is provided with an elongate opening 30, extending from approximately midway along portion b, along the entire length of portion c, to midway along portion d.

The configuration of the dials and spring unit is such that when suitably positioned in a lock, portions b, c of the spring arm are in face-to-face engagement with adjacent dial surfaces 24 as shown in Figure 2. When a dial is rotated in a counterclockwise direction (in Figure 2), resilient camming of the associated spring arm is effected by the junction between each pair of adjacent surfaces, and the arm then snaps back to engage the next successive pair of surfaces and provide positive step-by-step indexing of the dial.

Protrusions 26 do not interfere with counterclockwise rotation of the dials, since, as evident from Figure 2, the configuration of the right-hand ends of openings 30 provides clearance for the protrusions due to the extension of these ends of the openings into the terminal portions d of the arms. When a dial is rotated in a clockwise direction, however, it can only go up to a position in which protrusion 28 engages the arm surface e defining the left end of opening 30 (as shown in solid line of Figure 2). The arm surface then forms a stop for the protrusion, preventing further clockwise rotation of the dial. With the protrusion formed on the "number 5" indicium surface, in the stopped position, the "zero" indicium surface will be uppermost.This particular configuration of dial and spring provides a "zero-stop" enabling, if required, a lock having a set combination of OOO, to be brought into the on-combination setting entirely by feel, by rotating each dial in a clockwise direction until the step is encountered.

Combination lock dials and dial springs made in accordance with the invention have a number of advantages, e.g.: (a) by dispensing with detents between the adjacent dial indicia surfaces, a larger proportion of the dial periphery is available for the indicia themselves, so that in the case of relatively small dials, more clearly visible indicia can be used without having to resort to inking the indicia; (b) the face-to-face engagement of the spring with the dial indicia surfaces provides reliable positive step-by-step indexing, which is not dependent on accurately formed detent formations; (c) the provision of protrusions on the dials which cooperate with stop surfaces on the dial spring, provides the facility for obtaining a zerostop feature which is very positive in operation and not susceptible to forcing in the manner of known assemblies, as referred to previously;; (d) the face-to-face engagement of the dials and spring arms produces a smoother indexing action less subject to sticking than the known arrangements, so that the dial springs may be made of somewhat heavier spring material which is less subject to distortion; and (e) there is substantially no rubbing of the spring arms over the dial indicia surfaces and the dial and spring assemblies as herein described are found, in use, to have a less scratchy and less erratic feel than known spring and dial assemblies.

While only a single preferred embodiment of the invention has been described herein in detail, the invention is not limited thereby and modifications may be made within the scope of the attached claims. For example, the dials may each be formed with an integral enlargeddiameter thumbwheel to facilitate their manipulation. Additionally, surfaces 24 of the dials and arm portions b and c do not need to be strictly flat as in the illustrated embodiment, as long as face-to-face contact is provided between the dial indicia surfaces and the spring arms producing positive step-by-step indexing of the dials.

Claims

1. A rotary dial and dial spring assembly for use in a combination lock and the like, wherein the dial has a substantially polygonal cross section defining contiguous indicia surfaces around the periphery of the dial, and the spring has a dialengaging portion for providing positive step-bystep rotation of the dial between successive indicia settings by resilient face-to-face engagement of said portion of the spring with successive indicia surfaces of the dial.

2. An assembly in accordance with Claim 1, wherein the spring has a further dial-engaging portion extending from the dial-engaging portion aforesaid, said dial-engaging portions having an angle therebetween conforming with the included angle between a pair of adjacent indicia surfaces of the dial, whereby said dial-engaging portions engage adjacent incidia surfaces of the dial faceto-face.

3. An assembly in accordance with Claim 1, wherein the spring comprises a base portion and an arm extending from the base portion, and wherein said dial-engaging portion is formed on said arm.

4. An assembly as defined in Claim 3 including a plurality of axially adjacent dials, wherein the spring includes a plurality of arms for the respective dials.

5. A rotary dial and dial spring assembly for use in a combination lock and the like, wherein the dial includes a protrusion and the spring, which is adapted to engage the dial and provide positive step-by-step rotation of the dial, includes a stop surface that forms a stop for said protrusion when the dial is rotated in one direction, preventing further rotation of the dial in said one direction, said protrusion and said surface being ineffective to impede step-by-step rotation of the dial in the opposite direction.

6. An assembly as defined in Claim 6, wherein said protrusion is formed on the periphery of the dial, and the spring includes an arm adapted to engage the dial periphery and an elongate opening formed in the arm for receiving said protrusion, and wherein said stop surface comprises a surface of the arm defining one end of the opening, the other end of the opening being configured to allow free passage of said protrusion when the dial is rotated in said opposite direction.

7. A rotary dial and spring assembly in a combination lock and the like, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

7. An assembly as defined in Claim 6, wherein the dial is of substantially polygonal cross section defining contiguous dial indicia surfaces on the periphery of the dial, said protrusion being formed on one of said dial indicia surfaces, and wherein said arm comprises a first dial-engaging portion for engaging a dial indicium surface, a second dialengaging portion extending from said first dialengaging portion for engaging an adjacent dia! indicium surface and a terminal portion extending from said second dial-engaging portion, outwardly and away from said adjacent dial indicium surface, said opening being formed in said arm portions, and said stop surface being situated in said first dial-engaging portion with the other end of said opening extending into said terminal portion.

8. A dial spring for use in a combination lock and the like in conjunction with a dial of substantially polygonal cross section defining contiguous dial indicia surfaces disposed around the periphery of the dial, the spring including a spring arm having a first dial-engaging portion and a second dial-engaging portion extending from the first portion, the first and second portions defining an angle therebetween conforming to the included angle between a pair of adjacent indicia surfaces of the dial to enable said portions of the arm to engage adjacent indicia surfaces of the dial faceto-face.

9. A dial spring as defined in Claim 8, wherein said arm includes an elongate opening having one end in said first portion of the arm, the opening extending the entire length of said second portion of the arm.

10. A dial spring as defined in Claim 9, wherein the spring arm has a terminal portion extending from said second portion and bent outwardly away therefrom, said opening extending along part of the length of said terminal portion.

New claims filed on 1 5 July 1 982.

Superseded claims 1-10.

New claims:- 1-8.

1. A rotary dial and dial spring assembly in a combination lock and the like, wherein the dial has a substantially polygonal cross section defining contiguous indicia surfaces around the periphery of the dial, and the spring has a dial-engaging portion for providing positive step-by-step rotation of the dial between successive indicia settings by resilient face-to-face engagement of said portion of the spring with successive indicia surfaces of the dial, the dial having a portion which projects through an opening in the lock casing for manual manipulation of the dial.

2. An assembly, in accordance with Claim 1, wherein the spring has a further dial-engaging portion extending from the dial-engaging portion aforesaid, said dial-engaging portions having an angle therebetween conforming with the included angle between a pair of adjacent indicia surfaces of the dial, whereby said dial-engaging portions engage adjacent indicia surfaces of the dial faceto-face.

3. An assembly, in accordance with Claim 1, wherein the spring comprises a base portion and an arm extending from the base portion, and wherein said dial-engaging portion is formed on said arm.

4. An assembly, as defined in Claim 3, including a plurality of axially adjacent dials, wherein the spring includes a plurality of arms for the respective dials.

5. An assembly, as defined in Claim 1 , wherein the dial includes a protrusion and the spring includes a stop surfaces that forms a stop for said protrusion when the dial is rotated in one direction, preventing further rotation of the dial in said one direction, said protrusion and said surface being ineffective to impede step-by-step rotation of the dial in the opposite direction.

6. An assembly, as defined in Claim 6, wherein said protrusion is formed on the periphery of the dial, and the spring includes an elongate opening formed in the arm for receiving said protrusion, and wherein said stop surface comprises a surface of the arm defining one end of the opening, the other end of the opening being configured to allow free passage of said protrusion when the dial is rotated in said opposite direction.