GB2158864A - Roller catch - Google Patents

Abstract

A roller catch, e.g. for oven doors, comprises two rollers 16, 18 held in a housing 12 by means of a cage 14. The rollers run on bearings 48, 50 which engage in slots 36, 38 in the walls of housing 12. Channel-shaped cage 14 is then pressed down on to the housing with the rollers 16, 18 held as close together as possible. Leaf springs 60, 62 integral with the cage 14 urge the rollers together when the device is assembled, and lugs 70, 72 on the cage engage in slots 36, 38 to hold the cage in position. As shown in Fig. 6, the catch engages a stud-like keeper 78. <IMAGE>

Description

SPECIFICATION Roller catch The present invention relates to a new roller catch for use with a conventional striker pin to provide a push-on/pull-off fastening device, for example, for an oven door.

A known roller catch comprises a channelshaped housing and two rollers mounted in parallel in slots provided in opposed side walls of the housing for lateral movement towards and away from one another. The housing has two opposed lugs on each of which is mounted one arm of a U-shaped spring, the free arms of the springs each abutting one of the rollers and serving to bias the rollers together.

The roller catch is mounted on a first surface and a striker pin is mounted on a second surface which is to be releasably secured to the first surface. The striker pin has a bulbous head which, when the two surfaces are brought together, rides in between the rollers forcing them apart slightly against the bias of the two U-shaped springs. Once the bulbous portion has passed between the rollers, the rollers engage behind the bulbous portion due to the force of the springs to retain the pin in the catch. By applying a suitable pulling force urging the roller catch and striker pin apart, the bulbous portion of the pin again forces the rollers apart and the striker pin is freed from the roller catch.

Another known roller catch is similar to the type previously described except that there is one C-shaped spring overlying the rollers with the free ends of the spring embracing the rollers so as to bias them together. A disadvantage of this arrangement is that the Cshaped spring can be caused to spring off the rollers either by the striker pin passing between the rollers and hitting the middle of the spring or by the striker pin being slightly offset from the middle of the gap between the rollers when it hits them. Furthermore, the wrapping of the spring around the contour of the rollers inhibits their rolling movement which in turn inhibits smooth passage of the striker in and out of the catch.

According to the present invention we provide a roller catch comprising a housing, two rollers and a cage, the two rollers being mounted in parallel in the housing for relative lateral movement towards and away from one another, the cage being engageable on the housing to trap the rollers within the housing and two opposed spring arms integral with the cage and extending into the housing, the rollers being located between the spring arms and the spring arms being adapted resiliently to urge the rollers together.

The use of a cage having integral spring arms reduces the number of parts required in the roller catch whilst providing a secure spring arrangement.

In a particular embodiment the spring arms are generally J-shaped and preferably have inclined free ends to facilitate the assembly of the roller catch.

In a preferred embodiment, the cage is snap-engageable with the housing by means of resiliently interengageable lugs and recesses provided on the two parts. The housing and the cage may both be channelshaped so as to be engageable to form a generally rectangular section roller catch.

Preferably, the rollers are made of metal and have integral spindles thereby further reducing the number of parts required.

According to another aspect of the invention there is provided a method of assembling a roller catch as hereinbefore defined comprising the steps of: positioning the rollers in their closest position in the housing; employing holding means for holding the rollers in the closest position; pushing the cage onto the housing so that the two spring arms act to urge the rollers together.

Preferably, the rollers are of metal and the holding means comprise a magnetic plate.

A particular embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a side view of an assembled roller catch according to the present invention; Figure 2 is a perspective view of the housing of the roller catch shown in Figure 1; Figure 3 is an end view of the roller catch of Figure 7; Figures 4 and 5 are plan views from above and below respectively of the roller catch of Figure 1; Figure 6 is a side view of a cross-section of the line IV-IV in Figure 4 and showing a conventional striker pin engaged in the roller catch.

Figure 7 is a plan view from above of a modified roller catch.

Referring to the drawings, a roller catch 10 is generally symmetrical and comprises a housing 12, a cage 1 4 and two identical rollers 16 and 18.

Referring particularly to Figure 2, the housing 1 2 is made of mild steel and is of channel-section and comprises a base 20 and two upstanding side walls 22 and 24 contiguous therewith. The base 20 comprises a central square aperture 26 which extends completely across the width of the base 20 and has two semi-circular end portions 28 and 30 each comprising a circular aperture 32 and 34. The side walls 22 and 24 each comprise two open-ended horizontal slots 36 and 38 having chamfered portions 40 and 42 adjacent their open ends. The sides 22 and 24 are both provided with two upstanding lugs 44 and 46 at their uppermost corners.

The two rollers 1 6 and 18 are made of mild steel and each have an integral spindle 48 and 50 respectively configured for insertion in the slots 36 and 38 in the side walls 22 and 24.

The cage 14 its made of carbon steel and is of channel-section and comprises an upper horizontal wall 52 and two depending side walls 54 and 56. The upper wall 52 is provided with a longitudinally extending slot 58 and has two generally J-shaped spring arms 60 and 62 which extend inwardly from the ends of the slot 58 and extend downwardly into the housing 1 2. The free end 64 of each of the spring arms 60 and 62 respectively are inclined outwardly to facilitate assembly of the catch 1 0. The slot 58 is centrally widened to provide a part circular hole 66.

The side walls 54 and 56 are generally rectangular and slightly shorter than the upper wall 52 and each comprises a horizontal slot 68 having rounded ends. The side walls 54 and 56 each comprise a pair of inwardly inclined tongues 70 and 72. The two pairs of tongues 70 and 72 underlie cut-outs 74 and 76 in the upper wall 52.

To assemble the roller catch 10, the base 20 of the housing 1 2 is placed on a magnetic plate. The rollers 1 6 and 1 8 are positioned with their spindles 48 and 50 in the slots 36 and 38 of the side walls 22 and 24 of the housing 12. The rollers 16 and 18 are placed in their innermost position closest to one another and are held in that position due to the downward force exerted by the magnetic plate.The cage 14 is aligned above the housing 1 2 and placed over the housing 1 2 so that the side walls 54 and 56 of the cage 14 embrace the side walls 22 and 24 of the housing 1 2. The cage 14 is pushed downwardly onto the housing 1 2 and a resistance to pushing is felt due to the pairs of lugs 44 and 46 on the housing 1 2 abutting the interior surfaces of the pairs of tongues 70 and 72 on the cage 1 4. Further downward pushing on the cage 14 causes the side walls 54 and 56 of the cage to splay outwardly as the pairs of tongues 70 and 72 ride over the pairs of lugs 44 and 46.When the free end 64 of each of the spring arms 60 and 62 abut the rollers 1 6 and 18, the inclination of the ends 64 ensures that the spring arms 60 and 62 are deflected outwardly as they ride over the surfaces of the rollers 1 6 and 1 8. When the cage 14 has been fully pushed onto the housing 12 the pairs-of tongues 70 and 72 snap-engage in the open ends of the slots 36 and 38 due to the resilience of the material of the cage 14. Any upward movement of the cage 14 relative to the housing 1 2 is thereafter prevented by abutment of the tops of the pairs of tongues 70 and 72 with the upper edges of the slots 36 and 38 thereby retaining the cage 14 in position on the housing 12.

When the roller catch 10 has been assembled (see Figures 1 and 6) the side walls 54 and 56 of the cage 1 4 lie flush with the side walls 22 and 24 of the housing 1 2 thereby to form a roller catch of generally rectangular section. The pairs of lugs 44 and 46 locate in the cut-outs 74 and 76 in the upper wall 52 of the cage 14. The passage of the free end 64 of each of the spring arms 60 and 62 over the surfaces of the rollers 1 6 and 1 8 causes a spring force to be generated in the spring arms 60 and 62 so that they constantly urge the rollers 1 6 and 1 8 towards one another.

The roller catch 10 is particularly economical to produce because it comprises only four separate parts and is simple and quick to assemble.

Referring to Figure 6, a conventional striker pin 78 is circular in cross-section and comprises a bulbous head 80. In use, the striker pin 78, which is secured to a first surface (not shown), approaches the roller catch 10 which is secured to a second surface (not shown) by means of the apertures 32 and 34 in the base 20. The striker pin 78 enters the square aperture 26 and abuts the rollers 1 6 and 1 8.

As the striker pin 78 is pushed into the roller catch 10, the bulbous head 80 forces the rollers 1 6 and 1 8 apart against the spring force of the spring arms 60 and 62. When the widest part of the bulbous head 80 clears the rollers 1 6 and 1 8 these spring towards each other urged by the spring arms 60 and 62 and locate underneath the bulbous head 80 to retain the striker pin 78 in the roller catch 10 thereby releasably fastening the first surface and the second surface together. As shown in Figure 6, in this position the head 80 of the striker pin 78 protrudes through the part circular hole 66 in the cage 14.

When it is desired to separate the striker pin 78 from the roller catch 10, the striker pin 78 is pulled downwardly thereby causing the bulbous head 80 to force the rollers 1 6 and 1 8 apart against the spring force of the spring arms 60 and 62. When the widest part of the bulbous head 80 of the striker pin 78 passes out from between the rollers 1 6 and 1 8 the rollers again move towards each other under the spring force of the spring arms 60 and 62 back to their normal position. A typical pullout force for a roller catch of the type described is 121bs force (53.4 N).

Referring to Figure 7, a modified roller catch lOa is identical to the roller catch 10 described above apart from the configuration of the upper wall 52a of the cage 14a. The upper wall 52a has a slot 82 extending transversely of the longitudinally extending slot 58a. The transverse slot 82 facilitates use of the roller catch lOa with a striker pin having a flattened head and provides for a degree of tolerance in the relative positions of the striker pin and the roller catch.

The square aperture 26 provided in the base 20 of the housing 1 2 renders the roller catch 10, IOa suitable for use with both a conventional striker pin 78 as shown in Figure 6 and a striker pin of flattened cross-section.

The roller catch 10, 1 0a as described above is suitable for use as an oven door closure.

The roller catch 10, 1 Oa is secured in a recess in an oven door so that the square aperture 26 faces outwardly and is positioned opposite a striker pin secured at a corresponding position on the oven body. The compact design of the roller catch 10 obviates the need for a separate cover plate which is normally used with known roller catches and overlies the base of the housing for the sake of appearance.

It is also envisaged to use rollers of glass filled nylon instead of metal rollers. Nylon rollers are provided with separate metal spindles which are a friction fit in bores provided in the rollers. The provision of spindles which are a friction fit obviates the need for separate washers to be fastened to the ends of the spindles protruding through the side walls of the housing to prevent the spindles falling out of the rollers.

During assembly of a roller catch comprising nylon rollers, the housing is positioned on a brace comprising a pair of slidably adjustable fingers which are inserted into the open ends of the housing and adjusted so as to hold the rollers close together prior to fitting of the cage. When the cage has been fitted, the fingers are released and removed.

Claims (14)

1. A roller catch comprising a housing, two rollers and a cage, the two rollers being mounted in parallel in the housing for relative lateral movement towards and away from one another, the cage being engageable on the housing to trap the rollers within the housing and two opposed spring arms integral with the cage and extending into the housing, the rollers being located between the spring arms and the spring arms being adapted resiliently to urge the rollers together.

2. A roller catch according to Claim 1 wherein the spring arms are generally Jshaped.

3. A roller catch as claimed in Claim 1 or Claim 2 wherein the spring arms each have an inclined free end to facilitate assembly of the catch.

4. A roller catch according to any preceding claim wherein the cage is snap-engageable with the housing.

5. A roller catch as claimed in Claim 4 wherein the housing and the cage comprise a plurality of snappingly interengageable lugs and recesses.

6. A roller catch according to any preceding claim wherein the housing and the cage are both channel-shaped and together form a generally rectangular section catch.

7. A roller catch according to any preceding claim wherein the housing is provided with a generally square aperture for receiving a striker pin.

8. A roller catch according to any preceding claim wherein the cage is provided with a generally circular aperture for receiving a striker pin.

9. A roller catch according to any of Claims 1-7 wherein the cage is provided with a generally rectangular aperture for receiving a striker pin.

10. A catch according to any preceding claim wherein the rollers comprise integral spindles.

11. A catch according to any of claims 1-8 wherein the rollers comprise spindles which are a friction fit in the rollers.

1 2. A roller catch substantially as herein described with reference to and as illustrated in the accompanying drawings.

1 3. A method of assembling a roller catch according to any preceding claim comprising the steps of: positioning the rollers in their closest position in the housing; employing holding means for holding the rollers in the closest position; pushing the cage into engagement on the housing so that the two spring arms act to urge the rollers together.

14. A method according to Claim 1 3 wherein the rollers are of metal and the holding means comprise a magnetic plate.

1 5. A method according to Claim 13, wherein the rollers are of plastics material and the holding means comprise a pair of adjustable fingers.

1 6. A method substantially as herein described with reference to and as illustrated in the accompanying drawings.