GB2140071A - Weightlifting collar - Google Patents

Abstract

A weightlifting collar for retaining weightlifting plates or discs on a bar which comprises a pair of cooperating annular members 36 and 38, each having a central hub (6, 8). The hubs are of such a size that the hub 6 fits closely onto the bar and the hub 8 fits over it, and the two members have interengaging threads (40, 42), or cooperating cam surfaces, which lock them tightly together in use so that the hub 6, which has a segmented construction, is fixed inwardly to grip the surface of the bar. <IMAGE>

Description

SPECIFICATION Weightlifting collar This invention relates to clamps or collars for securing weightlifting plates to a bar.

Weightlifting bars or dumbell bars are usually provided with a fixed collar near each end, and weightlifting plates or discs are slid onto the end of the bar until they abut against the fixed collar. A separate locking collar is then slid onto the bar and locked into position agaist the disc to hold it in place. There are various types of collars presently in use, some of which comprise a simple ring with a radially extending threaded bore in which a locking screw is mounted, whilst others are made up of a number of separate components, such as a pair of semi-annular collars held together by wing nuts which are tightened to clamp the collar onto the bar.

All of these known types of collars suffer from the disadvantage that they are either cumbersome to use, or inconvenient because often special tools such as hexagonal keys are required to tighten them. Accordingly, the present invention provides a weightlifting collar comprising a first generally annular member having a radially inwardly flexible hub portion, and a second generally annular member including a hub portion which is adapted to fit over and cooperate with the flexible hub portion of the first member, in such a way as to urge it into engagement with a weightlifting bar, in use, and cooperating means on the said first and second members, whereby they may be locked together in engagement with the bar.

Preferably, the hub portion of the first member has a generally frusto-conical outer surface, which cooperates with a corresponding frusto-conical inner surface on the hub portion of the second member, so that the said first portion is flexed into engagement with the bar by the camming action of the two cooperating surfaces as the two members are pushed together.

Preferably, the cooperating means for locking the two members together comprise a plurality of circumferentially extending ramp surfaces on one of the members, arranged as a simple multi-start thread formation, and a corresponding number of radially outwardly projecting limbs, each adapted to engage with one of the ramps, on the other member.

Preferably, both members are made from a synthetic plastics material, and they may conveniently be formed by injection moulding.

Some embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a front elevation of a first component of a first form of the device of the invention; Figure 2 is a side elevation of the device of Fig. 1; Figure 3 is a diametral section, taken on the line A-A of Fig. 1; Figure 4 is a rear elevation of the device of Fig. 1; Figure 5 is a front elevation of a second component of the device of the invention; Figure 6 is a side elevation of the device of Fig. 5; Figure 7 is a diametral cross-section, on the line C-C of Fig. 5; Figure 8 is a rear elevation of the device of Fig. 5; Figure 9 is a diametral section corresponding to the section of Fig. 3, but showing a first component of a second embodiment of the invention;; Figure 10 is a diametral section, corresponding to the section of Fig. 7, but showing a second component of the second embodiment of the invention; and Figure 11 is a diametral section through the assembled device of the second embodiment of the invention.

Referring generally to the drawings, and particularly to Figs. 3 and 7, it will be seen that the device comprises two cooperating generally annular members 2 and 4, which are respectively formed with central hubs 6 and 8. The hub 6 of the member 2 has a generally frusto-conical outer surface 10, whilst the hub 8 has a corresponding frustoconical inner surface 12, which is adapted to fit over the surface 10.

The internal diameter of the hub 6 is such that it is a sliding fit on the end portion of a weightlifting bar which receives the weightlifting plate or plates, and the outer end of the hub is segmented, so as to form eight axially extending "fingers" 14. This allows the outer end of the hub to flex inwardly, when the member 4 is pushed over it, engaging tightly with the surface of the bar.

The first member 2 also comprises a generally cylindrical outer portion 16, with which the hub is integrally moulded, and the annular region between the outer cylinder 16, and the hub 6 carries four generally quadrant shaped ramp-like formations 20, with adjacent coextensive slots 22. One end of each slot is made wider, as indicated at 24, in a radial direction, to provide a lead-in portion for a cooperating locking foot on the second member 4, as described below.

The second member 4 is also made of a resilient plastics material and is provided with four locking feet 26, at its axially inner end, arranged in a cruciform pattern as shown in Fig. 8, and four finger grips 28 at its outer end, surrounding the hub 8, as best seen in Figs. 5 and 7.

Each of the feet 26 has an outer camming surface 27 terminating in an edge 32 forming a detent member, and in use, the feet 26 are pushed into the slots 24 for the first member, so that the camming surfaces 27 cooperate with corresponding ramp surface 31 at the outer ends of the slots 24, causing the feet 26 to be flexed inwardly until their edges 32 pass the end edges 30 of the surfaces 31.

The feet are then retained by engagement of the edges 32, against the edges 30, which form cooperating detents. In this position, the hub 8 loosely surrounds the hub 6.

The whole assembly is then slid up to the weights on the bar, and the member 4 is twisted in a clockwise direction, as seen in Fig. 5, relative to the member 2 (Fig. 1) so that the feet 26 ride up the ramps 20, causing the two parts to become tightly screwed together, and forcing the hub 8 tightly into engagement with the hub 6. This causes the fingers 14 to flex inwardly and thus grip the bar so that the device is tightly locked into position.

In order to engage positively with the weightlifting disc on the bar, the member 2 may be provided with castellations or lugs 34 adapted to cooperate with mating formations around the hub of the disc, and this also has the beneficial effect of preventing the disc from rotating.

As an alternative to the ramped locking arrangement of Figs. 1 to 8. a second embodiment of the invention, illustrated in Figs.

9 to 11, utilises a threaded locking arrangement and includes a first annular member 36 (Fig. 9) which comprises a female threaded portion, and a second annular member 38, Fig. 10, which comprises a male-threaded portion. It will thus be appreciated that the members 36 of Fig. 9 and 38 of Fig. 10 correspond in function respectively, to the members 2 and 4 of Figs. 3 and 7.

As shown in Fig. 9, the member 36 again has a hub 6 with a frusto-conical outer surface 10 which engages with a corresponding inner surface 1 2 of a hub 8 of the member 38. The hub 6 is segmented so that it can flex inwardly to engage tightly with the weightlifting bar when the hubs of the two members are tightly engaged, but in this case the locking engagement is achieved by means of female threads 40 on the inner surface of the outer cylindrical portion 16 of the member 36, which cooperates with male threads 42 on the outer surface of the member 38. The manner in which the two components are locked into engagement is illustrated in Fig. 11.

Claims (6)

1. A weightlifting collar comprising a first generally annular member having a radially inwardly flexible hub portion, and a second generally annular member including a hub portion which is adapted to fit over and cooperate with the flexible hub portion of the first member, in such a way as to urge it into engagement with a weightlifting bar, in use, and cooperating means on the said first and second members, whereby they may be locked together in engagement with the bar.

2. A weightlifting collar according to claim 1 in which the hub portion of the first member has a generally frusto-conical outer surface, which cooperates with a corresponding frusto-conical inner surface on the hub portion of the second member, so that the said first portion if flexed into engagement with the bar by the camming action of the two cooperating surfaces as the two members are pushed together.

3. A weightlifting collar according to claim 1 or claim 2 in which the cooperating means for locking the two members together comprises a pair of cooperating thread formations, one of which is formed on the first member and the other of which is formed on the second member.

4. A weightlifting collar according to claim 1 or claim 2 in which the cooperating means for locking the two members together comprise a plurality of circumferentially extending inwardly facing ramp surfaces formed on one of the members, and a corresponding member of radially outwardly projecting limbs each adapted to engage with one of the ramps, on the other member.

5. A weightlifting collar substantially as herein described with reference to Figs. 1 to 8 of the accompanying drawings.

6. A weightlifting collar substantially as herein described with reference to Figs. 9 to 11 of the accompanying drawings.