FASTENERS

Abstract: A fastener comprises a stud-like member (10) having an external threaded portion (18) and a nut-like member (20) having an internal threaded portion (22, 22) which is so configured that, with the nut-like member (20) at a first inclination relative to the stud-like member (10), the internal threaded portion of the nut-like member can be slid along the stud-like member whereas, with the nut-like member (20) at a second inclination relative to the stud-like member (10), the internal threaded portion of the nut-like member can be brought into threaded engagement with the stud-like member, the nut-like member preferably having a generally annular body (20) surrounding a bore (24), with offset and opposed parts (26, 28) of the body missing so that the bore has convergent-divergent parts, and with offset and opposed projections (22, 22) on the convergent-divergent parts of the bore forming the internal threaded portion.

Description: Fasteners The present invention relates generally to fasteners and is more especially but not exclusively concerned with fasteners for use with push-button switches in fruit machines. It is well known for fruit machines to be provided with controls for operation by players of the fruit machines. Typically, the controls are in the form of push-button switches which can be of different shapes, sizes and colours and, if illuminated, can be fully or partly illuminated. The different push-button switches are similar, however, in enabling push-buttons to be reciprocally movable with respect to push-button switch mountings. Typically, the push-button switch mountings are to be secured to supports in the form of panels such as front panels of the fruit machines. Examples of known push-button switches are to be found in GB-A-2279500 to which the reader is invited to refer. It will be seen that the push-button switches are secured by the use of nuts which screw along threads provided by body parts of the push-button switch mountings to sandwich the panels firmly between the nuts and bezel parts of the push-button switch mountings. A particular problem, in terms of the assembly procedure, is that because the panels to which the pushbutton switches are to be secured come in a large range of different thicknesses, the threads need to be sufficiently long to cope with the thickest of the possible panel thicknesses, and thus the nuts need to be screwed along substantial lengths of the threads when applied to the thinnest of the possible panel thicknesses. It would be desirable to avoid time wasted in the assembly procedure. One answer to the problem is the invention of our WO 97/23934 to which the reader is again invited to refer - in use, the nut-like member can be quickly slid along the stud-like member at one orientation and then turned through, for example, just a quarter turn or 90° in order to secure the fastener. Another answer to the same problem is the present invention, in which a fastener comprises a stud-like member having an external threaded portion and a nut-like member having an internal threaded portion which is so configured that, with the nut-like member at a first inclination relative to the stud-like member, the internal threaded portion of the nut-like member can be slid along the stud- like member whereas, with the nut-like member at a second inclination relative to the stud-like member, the internal threaded portion of the nut-like member can be brought into threaded engagement with the stud-like member. In use, the nut-like member can be quickly slid along the stud-like member when at said first relative inclination and can then be tilted to said second relative inclination to achieve threaded engagement with the stud- like member. Clearly, when in said threaded engagement, the nutlike member can be either tightened or loosened (advanced or retracted) by screwing or unscrewing relatively to the stud-like member. Preferably, the stud-like member is formed of a plastics material and has an external threaded portion which is circu ferentially continuous. Preferably, the nut-like member is formed of a plastics material, and has a generally annular body surrounding a bore, with offset and opposed parts of the body missing so that the bore has convergent-divergent parts, and with offset and opposed projections on the convergent-divergent parts of the bore forming the internal threaded portion. Preferably, a leading face of the nut-like member, considered in the direction of movement during assembly with the stud-like member, is not perpendicular to a longitudinal axis of the nut-like member. The angle of inclination of the leading face may be less than 5°. Also preferably, a leading face of the nut-like member, considered in the direction of movement during assembly with the stud-like member, is provided with a pair of studs. The leading face may form part of a washer. The nut-like member may be formed with depressions in an outer surface thereof. The stud-like member may form part of a push-button switch mounting, with another part of the push-button switch mounting including a bezel-like member. Examples of fasteners in accordance with the present invention are shown in the accompanying drawings wherein: - Figure 1 is a longitudinal cross-section through a push-button switch mounting; Figures 2 to 6 are, respectively, front, rear, plan, underplan and end views of a nut for use with the pushbutton switch mounting of Figure 1; Figures 7 and 8 are, respectively, cross-sectional views taken along the lines X-X and Z-Z of Figure 2; and Figure 9 is similar to Figure 6 but illustrates a modified nut. Referring initially to Figure 1, a stud-like member is shown in the form of a push-button switch mounting 10 of conventional construction, including a recess defined by a bezel 12 and a base 14 with a hollow cylinder 16 extending from the centre of the base 14. The external circumferential surface of the hollow cylinder 16 is formed with a helical thread 18. Referring now to Figures 2 to 8 , a nut-like member is shown in the form of a ring 20 having a pair of internal projections 22 on a bore 24 so that, with the ring 20 at a first relative inclination its projections 22 are slidable over the helical thread 18 whereas, with the ring 20 at a second relative inclination its projections 22 are in threaded engagement with the helical thread 18. It will be appreciated that, in order to allow the ring 20 to be moved between said first and second relative inclinations, the ring 20 should be of a special configuration. As shown, opposed and offset parts 26 and 28 of the ring 20 at its leading and trailing edges may be in effect removed or, more accurately, not provided when the ring 20 is formed for example by moulding from a plastics material so that the bore 24 is formed of convergent-divergent parts with one of the projections 22 being provided in each of the convergent-divergent parts. Typically, the ring 20 would be applied to the pushbutton switch mounting 10 by pushing over and along the hollow cylinder 16, but would be removed from the hollow cylinder 16 by unscrewing the projections 22 along the helical thread 18. To assist in application of the ring 20 to the hollow cylinder 16, the outer surface of the ring 20 may be formed with depressions 30 for co-operation with complementary protuberances on a hollow feed funnel (not shown) . To assist in retention, after the ring 20 has been applied to the hollow cylinder 16, the leading end of the ring 20 may be formed with a washer 32 for abutment against a panel (not shown) . The nut-like member as illustrated in Figures 2 to 8 is moved between its said first and second relative inclinations by tilting through 24.3°, but more generally the dimensions of the nut-like member are such that the angle of tilt between its said first and second relative inclinations can be in the range 10° to 35°, preferably 15°. The nut-like member, when held in its said first relative inclination, can be pushed over and along the stud-like member. In practice, the travel would be limited by abutment with a workpiece, such as a panel. The nutlike member can then be tilted to its said second relative inclination by pivoting about its points of contact with the panel. To achieve threaded engagement of the nut-like member with the stud-like member, however, it may also be necessary, in any given case, for the nut-like member to be turned about the stud-like member. It has been found that there is a greater window of opportunity for threaded engagement to be achieved if the tilting action is increased i.e. increasing the angle of tilt can decrease the angle of turn necessary to achieve threaded engagement. Figure 9 shows a modified ring 20' with a cutaway part 26' in a washer 32'. The leading face 34' of the washer 32' is not perpendicular to the longitudinal axis A-A of the ring 20', but slopes away from the cutaway part 26' at a small angle of preferably less than 5°. Alternatively, or additionally, the leading face 34' of the washer 32' is provided with a pair of studs 36' near its junctions with the cutaway part 26'. In both of the above-described modifications the effect is to increase the potential angle of tilt and thereby allow a decrease in the angle of turn necessary to achieve threaded engagement.

Claims: CLAIMS 1. A fastener comprising a stud-like member having an external threaded portion and a nut-like member having an internal threaded portion which is so configured that, with the nut-like member at a first inclination relative to the stud-like member, the internal threaded portion of the nutlike member can be slid along the stud-like member whereas, with the nut-like member at a second inclination relative to the stud-like member, the internal threaded portion of the nut-like member can be brought into threaded engagement with the stud-like member. 2. A fastener according to claim 1, in which the external threaded portion of the stud-like member is circumferentially continuous. 3. A fastener according to claim 1 or claim 2, in which the nut-like member has a generally annular body surrounding a bore, with offset and opposed parts of the body missing so that the bore has convergent-divergent parts, and with offset and opposed projections on the convergent-divergent parts of the bore forming the internal threaded portion. 4. A fastener according to any preceding claim, in which a leading face of the nut-like member, considered in the direction of movement during assembly with the stud-like member, is not perpendicular to a longitudinal axis of the nut-like member. 5. A fastener according to claim 4, in which the angle of inclination of the leading face is less than 5°. 6. A fastener according to any preceding claim, in which a leading face of the nut-like member, considered in the direction of movement during assembly with the stud-like member, is provided with a pair of studs. 7. A fastener according to any one of claims 4 to 6 , in which the leading face forms part of a washer. 8. A fastener according to any preceding claim, in which the nut-like member is formed with depressions in an outer surface thereof. 9. A fastener according to any preceding claim, in which the stud-like member is part of a push-button switch mounting, with another part of the push-button switch mounting including a bezel-like member.

Inventors: SCRIVEN JOHN LEONARD, SCRIVEN, JOHN, LEONARD
Applicants: SCRIVEN JOHN LEONARD, STARPOINT ELECTRICS LTD, SCRIVEN, JOHN, LEONARD, STARPOINT ELECTRICS LIMITED
Application year: 1997
Main classification: H02B1
IPC codes: F16B37, H02B1