GB2050489A

GB2050489A - Clamp

Info

Publication number: GB2050489A
Application number: GB7923246A
Authority: GB
Original assignee: CAMLOC IND FIXINGS Ltd
Current assignee: CAMLOC IND FIXINGS Ltd
Priority date: 1979-07-04
Filing date: 1979-07-04
Publication date: 1981-01-07
Also published as: GB2050489B

Abstract

A clamping device for securing a floor panel 10 to a support 11, comprises a clamping element 12 mounted on one end of a pin 13 by virtue of the engagement between a cross-pin 14 and a pair of longitudinal grooves 16 in the clamping element. A radial arm 17 on the clamping element 12 engages the member 11. The other member 10 is engaged by a flange 19 on a cup 18, a spring 21 being arranged on the pin 13 to act between the base 20 of the cup and the head 22 of the pin. Removal of a plug 24 from the open end of the cup 18 allows access to a slot 23 in the head of the pin 13 for rotation of the pin and clamping element 12 as one unit from the clamping position (as shown) to a released position. In both the clamping and the released positions a rib on a washer 25 fixed to the member 10 engages recesses in the clamping element 12 to provide an indexing detent. <IMAGE>

Description

SPECIFICATION Clamping Method and Device The invention relates to a method and a device for holding two members together.

According to a first aspect of the invention there is provided a method for holding two members together, comprising the steps of passing a pin into a hole in a first of the members adjacent the second member, securing a clamping element to the first member by mounting it on one end of the pin, the clamping element being urged towards the first member by a spring arranged on the pin, the clamping element and pin being rotatable as one unit relative to the first member between a clamping position in which an arm on the clamping element extending radially away from the pin engages the second member and a released position in which the arm does not engage the second member, at least one projection or recess being defined on the clamping element for engagement, when the clamping element is in the clamping position, with a recess or projection defined on the first member, there being provided means to enable a torque to be applied to the pin and means to enable determination of the orientation of the pin relative to the first member, whereby a user can determine by inspection of the pin whether the clamping element is in the clamping position.

Further aspects of the invention provide a clamping device for holding two members together, and an assembly comprising two members and a clamping device.

The invention will be further described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a section through a clamping device constructed according to the invention; and Fig. 2 is a view of two elements of the clamping device shown in Fig. 1, the elements being shown spaced apart for clarity.

Referring to the drawings, a clamping device for clamping together two overlapping members 10 and 11 is shown. The two members could, for example, be a floor panel 10 and a supporting structure 11. The clamping device comprises a cup 18 mounted in a hole 27 in the member 10, the cup having a flange 19 which engages the face of the member 10 remote from the member 11, i.e. the upper face. The cup 1 8 has a base 20 against which bears the lower end of a spring 21.

Passing through the spring 21 and through a hole 28 in the base 20 of the cup 18 is a pin 13, the upper end of the spring 21 bearing against the head 22 of the pin 13.

A cross-pin 14 is fixed in a transverse bore near the lower end of the pin 13, and engages the ends of a pair of grooves 16 in a bore 43 through a clamping element 12 mounted on the pin 13.

The lower portion of the bore 43 is a close fit on the pin 13. The engagement between the crosspin 14 and the ends of the grooves 16 and the action of the spring 21, results in the clamping element 1 2 being urged upwardly towards the member 10. Consequently, an arm 17 on the clamping element which extends radially away from the pin 1 3 engages the lower face of the member 11.

A washer 25 is fixed, preferably by use of an adhesive, to the lower face of the member 10.

The washer 25 has a downwardly directed rib in two portions 29 and 30 arranged at diametrically opposite positions with respect to the hole in the washer, which is arranged to co-incide with the hole 27 in the member 10.

The engagement between the cross-pin 14 and the grooves 16 in the bore 43 of the clamping element 12 constrains the clamping element against rotation relative to the pin 1 3. The pin 13 and clamping element 1 2 can be rotated as one unit about the longitudinal axis of the pin between a clamping position (shown in Fig. 1) and a released position in which the arm 1 7 does not engage the member 11. A slot 23 is provided in the head 22 of the pin 13 to enable rotation of the pin and clamping element by application of a torque to the head of the pin e.g. by means of a screw-driver. In both the clamping position and the released position the portions 29 and 30 of the rib on the washer 25 engage recesses 31 to 34 in the face of the clamping element 12 adjacent the member 10.

Referring to Fig. 2, the clamping elementl2 is shown in the orientation relative to the washer 25 which it occupies when in the clamping position shown in Fig. 1.

The portions 29 and 30 of the rib on the washer 25 are received in a pair of recesses 31 and 32 respectively. When the clamping element 12 is in the released position the portions 29 and 30 of the rib are received in a second pair of recesses 33 and 34 respectively. Each recess 31 to 34 has one gradual slope 35 (see recess 31) and one steep slope 36. The slopes of the recesses are so arranged as to limit the rotation of the clamping element relative to the washer 25 to the angular separation between adjacent recesses. When the clamping element is in the clamping position the steep slopes of the recesses 31 and 32 prevent rotation of the clamping element in one direction.Rotation of the clamping element in the opposite direction results in the portions 29 and 30 of the rib on the washer 25 moving along the gradual slopes out of the recesses 31 and 32 and eventually into recesses 33 and 34, again along the gradual slopes.

When the portions 29 and 30 of the rib are in the recesses 33 and 34, further rotation is prevented by engagement with the steep slopes of those recesses and the clamping element can only be returned to the clamping position by rotation in the opposite direction.

The recesses 33 and 34, which are engaged by the portions 29 and 30 of the rib on the washer 25 when the clamping element is in the released position, are not as deep as the recesses 31 and 32. Consequently, the clamping element may be closer to the member 10 in the clamping position than in the released position, unless the engagement of the arm 17 by the member 11 prevents the clamping element approaching the first member to the extent allowed by the relative dimensions of the recesses 31 and 32 and the portions 29 and 30 of the rib.

The regions 37 and 38 of the upper face of the clamping element which are traversed by the portions 29 and 30 of the rib as the clamping element is rotated between the clamping and released positions are a smaller height above the bases of the recesses 31 and 32 than are the remaining regions 39 and 40 of the upper face.

It will be seen from Fig. 2 that the four recesses 31 to 34 on the clamping element are spaced apart at angular separations of approximately 900, where the angular separations are determined with regard to the centres of the bases of the recesses. The recesses are in two pairs; the pair 31 and 32 receiving the rib on the washer in the clamping position and the pair 33 and 34 receiving the rib in the released position.

One recess of each pair, i.e. recess 31 and recess 34 is spaced at an angular separation of approximately 450 from the arm 17 on the clamping element.

The method of assembly of the clamping device is as follows:- The hole 27 is prepared in the member 10 adjacent the region of overlap with the member 11, the hole 27 being large enough to receive the cup 1 8. A second, smaller hole which need not pass completely through the member 10 is prepared from the under side of the member. The second hole receives a tab 41 on the washer 25 when this is bonded to the lower surface of the member 10, and thus assists in preventing rotation of the washer 25 relative to the member 10. As shown in Fig. 2, the tab 41 is preferably on the side of the washer 25 remote from the arm on the clamping element when the clamping element is in the clamping position relative to the washer 25.Since the clamping devices will often be in use near an edge 42 of the member 10, this location of the tab 41 will generally result in the second hole being further from the edge 42 than is the hole 27.

The pin 13 is passed through the spring 21 and the cup 18, and the cross-pin 14 is then fixed in the transverse bore through the pin, preferably by swaging.

When the washer 25 has been fixed to the member 10 the combination of pin 13, spring 21, cup 18, and cross-pin 14 is fed into the hole 27 from the upper side, i.e. from the side remote from the member 11, until the flange 19 of the cup is in contact with the upper face of the member 10.

Pressure is applied to the head 22 of the pin 1 3 and the clamping element 12 is offered to the end of the pin 13 in the orientation shown in Fig.

1, but the pin 13 is displaced through 900 relative to the clamping element 12 so that the ends of the cross-pin 14 can pass through a first pair of grooves 1 5 defined in the bore through the clamping element. When the cross-pin 14 emerges from the lower end of the clamping element, the pin is rotated through 900 relative to the clamping element. The pressure on the pin 13 is released, and the pin 1 3 is retracted through the bore in the clamping element, under the action of the spring 21, the ends of the cross pin 14 being received in a second pair of grooves 1 6 defined in the bore of the clamping element. The grooves 16, unlike the grooves 15, terminate part of the way along the bore and so the cross-pin 14 eventually engages abutment faces at the ends of the grooves 1 6.When the ends of the cross-pin 14 are in engagement with the ends of the grooves 16, the spring 21 acts to urge the clamping element 12 toward the member 10.

The engagement between the cross-pin 14 and the grooves 1 6 constrains the clamping element against rotation relative to the pin 13.

Consequently, a screw-driver can be used to engage the slot 23 in the head of the pin 13, to apply pressure to the head of the pin, and to rotate the clamping element between the clamping position shown in Fig. 1 in which the arm 1 7 engages the member 11 and the released position in which the arm 1 7 does not engage the member 11. The interaction in the two positions of the recesses 31 to 34 and the portions 29 and 30 of the rib on the washer 25 has been described above. The orientation of the slot 23 in the pin 13 relative to the member 10, e.g. by reference to the edge 42 of the member, can serve as an indication of whether the clamping element is in the clamping or the released position.

The spring 21 always acts to urge the clamping element towards the member 10 but also allows for accommodation of slight variations in the relative dimensions of various parts of the assembly. It will be seen from Fig. 1 that the clamping device need not project very far above the upper face of the member 10, and a plug 24 can be fitted into the open end of the cup 1 8.

When the clamping device has been assembled, a retaining washer 26 is fitted into an annular groove near the free end of the pin 13. The outer diameter of the retaining washer is larger than the diameter of the lower portion of the bore 43 through the clamping element. If the clamping element becomes detached from the cross-pin 14, the retaining washer 26 will prevent it becoming separated from the pin 13.

It will be appreciated that the invention is not limited to the one embodiment described and shown in the drawings. For example, a washer 25 need not be employed if the portions 29 and 30 of the rib are defined directly on the member 10.

It would be possible to define ribs or other projections on the clamping element 12 to be received in recesses defined on the member 10.

The spring 21 could be arranged on the pin 13 below the clamping element 12. The clamping device is applicable not only to overlapping members.

Claims

1. A method for holding two members together, comprising the steps of passing a pin into a hole in a first of the members adjacent the second member, securing a clamping element to the first member by mounting it on one end of the pin, the clamping element being urged towards the first member by a spring arranged on the pin, the clamping element and pin being rotatable as one unit relative to the first member between a clamping position in which an arm on the clamping element extending radially away from the pin engages the second member and a released position in which the arm does not engage the second member, at least one projection or recess being defined on the clamping element for engagement, when the clamping element is in the clamping position, with a recess or projection defined on the first member there being provided means to enable a torque to be applied to the pin and means to enable determination of the orientation of the pin relative to the first member, whereby a user can determine by inspection of the pin whether the clamping element is in the clamping position.

2. A method according to Claim 1, and further comprising the step of fixing a washer to the first member to surround the hole, the said recess or projection defined on the first member being on the washer.

3. A method according to Claim 1 or 2, and further comprising the step of so mounting a cup in the hole in the first member that a radially outwardly extending flange around the open end of the cup engages the face of the first member remote from the clamping element, the body of the pin passing through a hole in the base of the cup, and arranging the spring to act between the base of the cup and a head on the pin.

4. A method according to any of Claims 1 to 3, wherein mounting the clamping element on the pin comprises fixing a cross-pin in a transverse bore through the pin near the end on which the clamping element is to be mounted, passing that end of the pin through a bore in the clamping element, the ends of the cross-pin passing through a first pair of grooves along the bore, until the cross-pin emerges from the bore, rotating the pin relative to the clamping element, and retracting the pin through the bore in the clamping element, the ends of the cross-pin being received in a second pair of grooves along the bore, until the cross-pin engages abutment faces provided at the ends of the second pair of grooves.

5. A method according to any preceding claims, and further comprising the step of mounting a retaining washer in an annular groove in the pin, whereby the clamping element is prevented from becoming separated from the pin.

6. A clamping device for holding two members together, comprising a pin to be passed into a hole in a first of the members, a washer to be fixed on the first member to surround the hole, a clamping element to be secured to the first member by being mounted on one end of the pin adjacent the washer, and a spring to be arranged on the pin whereby the clamping element can be urged towards the first member, the clamping element and pin being rotatable as one unit relative to the first member between a clamping position in which an arm on the clamping element extending radially away from the pin can engage the second member and a released position in which the arm does not engage the second member, at least one projection or recess being defined on the washer for engagement, when the clamping element is in the clamping position, with a recess or projection defined on the clamping element, there being provided means to enable a user to apply a torque to the end of the pin remote from the clamping element, and means to enable determination of the orientation of the pin relative to the first member, whereby the user can determine by inspection of the pin whether the clamping element is in the clamping position.

7. A device according to Claim 6, wherein a rib is defined on the washer in two portions arranged at diametrically opposed positions with respect to the hole in the first member, the clamping element having two pairs of recesses, a first pair receiving the two portions of the rib on the washer when the clamping element is in the clamping position, and the second pair receiving the two portions of the rib when the clamping element is in the released position.

8. A device according to Claim 7, wherein the four recesses on the clamping element are spaced apart at angular separations of approximately 90c.

9. A device according to Claim 7 or 8, wherein .the recesses of the first pair are deeper than the recesses of the second pair.

10. A device according to any of Claims 7 to 9, wherein one recess of each of the two pairs of recesses on the clamping element is spaced at an angular separation of approximately 45 from the arm on the clamping element.

11. A device according to any of Claims 7 to 10, wherein one side of each recess has a gradual slope along which a portion of the rib on the washer can enter or leave the recess, and the opposite side has a steep slope, the recesses being arranged to allow rotation of the clamping element from the clamping position to the released position in one direction only, and to allow rotation from the released position to the clamping position in the opposite direction only.

12. A device according to Claim 1 1, wherein the regions of the upper face of the clamping element which are traversed by the portions of the rib on the washer as the clamping element is rotated between the clamping position and the released position are spaced by a smaller distance from the bases of the first pair of recesses than are the remaining regions of the upper face of the clamping element.

1 3. A device according to any preceding Claim, wherein a cup is so mounted in the hole in the first member that a radially outwardly extending flange around the open end of the cup engages the face of the first member remote from the clamping element, the body of the pin passing through a hole in the base of the cup, the pin having, at the end remote from the clamping element, a head of larger diameter than the hole in the base of the cup.

14. A device according to Claim 13, wherein the spring is arranged to act between the base of the cup and the head of the pin.

15. A device according to any of claims 6 to 14, wherein a cross-pin is fixed in a transverse bore through the pin near the end on which the clamping element is to be mounted, a bore in the clamping element having a first pair of grooves to receive the ends of the cross-pin as the pin is passed along the bore, and a second pair of grooves, angularly spaced from the first pair, to receive the ends of the cross-pin when the pin is retracted through the bore, abutment faces being provided at the ends of the second pair of grooves to engage the ends of the cross-pin.

16. A device according to any of Claims 6 to 1 5, wherein a slot is provided in the end of the pin remote from the clamping element.

17. A device according to any of claims 6 to 16, wherein a retaining washer is mounted in an annular groove in the pin, whereby the clamping element is prevented from becoming separated from the pin.

18. An assembly comprising two members held together by a clamping device according to any of Claims 6 to 17.

19. A method for holding two members together, the method being substantially as herein described with reference to the accompanying drawings.

20. A clamping device substantially as herein described with reference to the accompanying drawings.

21. An assembly comprising two members held together by a clamping device, the assembly being substantially as herein described with reference to the accompanying drawings.