GB1581825A - Rivetting - Google Patents

Description

(54) RIVETTING (71) We, METAL BOX LIMITED, of Queens House, Forbury Road, Reading RG1 3JH, Berkshire, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following state ment:- The present invention concerns the attachment of pivotable members to thin-walled members, and more particularly, but not exclusively, the invention relates to the attachment of handles to paint cans.

British Patent No. 1,161,847 describes a rivet having a head and shank. The shank has a wider portion which joins the head to a narrower shank portion. When such rivets are used to fix a handle in pivotable engagement with a can body, the rivet is first inserted in a hole in the can body. The wider portion of the shank is then sheared down to form a shoulder, so that the can body is gripped between the shoulder and the head of the rivet.

The handle is then staked onto the narrower portion of the shank of the rivet. Experience has shown that the area of contact between the shoulder and the can body is limited by the manner in which the material of the wider portion of the shank deforms. Increasing tool pressure may result in enlargement of the hole in the can body, rendering it difficult to maintain a leak-proofjoint.

In accordance with a first aspect of the invention there is provided a connection wherein a first member is attached to a second, thin walled, member by means of a stud having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, the hollow portion of the shank being deformed outwardly to form a bulge which together with the head grips the second, thin walled, member and the free end portion of the shank being deformed outwardly to secure the first member pivotably to the second, thin walled, member.

The blind bore may either extend the length of the shank and terminate approximately at the head; alternatively it may extend through the head and into the shank, terminating within the shank at some distance from the free end of the latter.

According to a second aspect of the invention there is provided a method of attaching a first member to a second, thin walled, member by means of a stud, having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, comprising inserting the shank through a hole in the second, thin walled, member, engaging the free end portion of the shank with a tool, compressing axially a portion of the shank, which is between the free end portion and the second member, by axial motion of the tool relative to an anvil supporting the stud head to form a bulge which, together with the stud head, grips the second, thin walled, member, fitting the free end portion of the shank through a hole in the first member and deforming the free end portion to secure the first member pivotably to the second member.

In order that the invention may be more fully understood various embodiments thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a section through a known attachment stud ("rivet") prior to being staked to a portion of a can wall; Figure 2 is a section through the rivet of Figure 1 after being staked to a can wall in a known manner; Figure 3 is a section through a stud for use in a connection according to the invention in the form of a rivet, prior to being staked to a can wall; Figure 4 shows the rivet of Figure 3 after staking; Figure 5 shows a can having a strip handle attached thereto by a respective rivet as shown in Figures 3 and 4 at each end of the handle; Figure 6 is a section through a portion of the can of Figure 5, illustrating how the handle is fixed to the can;; Figure 7 is a section through an anvil, a hollow first tool, the rivet and the can wall before rivetting; Figure 8 is a view similar to Figure 7 after the rivet has been fixed to the wall; Figure 9 is a section through the anvil, a second tool and the rivet and the handle; Figure 9A and 9B show modified embodiments of the second tool; and Figures 10 to 12 show successive stages in the staking of an alternative embodiment of the rivet.

Figure 1 shows a known rivet 1 having a head 2, and a shank comprising a first cylindrical portion 3 of larger diameter fitted in a hole in a can wall 4 and a second cylindrical portion S of smaller diameter than the portion 3. The second cylindrical portion S has a central bore 6.

Figure 2 shows the rivet I after it has been staked to the wall 4 by pressure exerted upon a shoulder 7, presented by the first cylindrical portion 3, while the head 2 is restrained by an anvil (not shown). The rivet is therefore firmly fixed to the can wall 4 and the upstanding shank portion 5 can be deformed to attach a handle or other member to the can.

Depending on the degree of deformation of the portion 5, the handle or other member may be retained pivotably or firmly. The bore 6 in the portion S reduces the load necessary to deform the portion 5. However the first cylindrical shank portion 3 is not pierced and is wider than the shank portion S so it therefore requires larger staking loads than the portion 5; these loads are, in fact, so large that results tend to be erratic and leakage sometimes occurs past the rivet.

An attachment stud for use in a connection according to the invention in the form of a rivet 8 is shown in Figure 3. It has a head 9, and a shank 10 of constant external diameter which fits in a hole in a can wall 12. A blind bore 11 extends approximately the full length of the shank and may also extend a little way into the head 9. Therefore the shank is deformable to the shape shown in Figure 4 to fix the rivet 8 to the wall 12 by the head 9 on one side of the wall and a bulge 13 in the shank 10 on the other. The undeformed part of the shank 10 may be staked to retain a handle or other member as shown in Figure 6.

In Figure 5 a paint can 14 is shown having a strip handle 15 fixed thereto by a respective rivet 8 at each end of the handle. One of these rivets 8 is shown sectioned in Figure 6 to illustrate how the hollow shank 10 (Figure 4) has been spread to provide a handle-retaining flange 17.

Figures 7 to 9 show how each rivet 8 may be attached, firstly to the can 14 and subsequently to the handle 15. The rivet shank 10 is first pushed through a hole in the can 14 up to the rivet head 9, after which the can and rivet are placed between the anvil 18 and top tool 19 of a press, the head 9 of the rivet 8 being supported by the anvil 18.

As depicted in Figure 8, the top tool 19 of the press is then brought down so that a recess 20 formed in it receives and confines an end portion of the rivet shank 10. The top face 21 of the recess 20 presses on the free end of the shank 10 and by so doing deforms a portion of the shank outwardly and so creates the bulge 13 which, together with the rivet head 9, retains the rivet in the hole in the can 14.

Although the bulge 13 is shown wholly flattened, only partial flattening of the bulge may sometimes be preferred. During the formation of the bulge the confinement of the end portion of the shank 10 within the recess 20 ensures that little or no deformation of that portion occurs; thus the deformation of the shank is restricted to the shank portion lying between the can 14 and the press tool 19.

Subsequent to the attachment of the rivet 8 to the can 14 in this way, the can and rivet are removed from the press and the respective end of the handle is fitted over the free end of the shank 10. The combination of can rivet and handle is then presented between the anvil 18' and top tool 23 of another press (Figure 9). The operative lower surface of the tool 23 is convex in the form of a shallow cone or other suitable configuration and by lowering the tool onto the free end of the shank 10 the shank end portion is spread to form the retaining flange 17, leaving a clearance to permit pivoted movement.

In Figure 9A a modified top tool 23A is shown which has a peg portion 23B adapted for entry into the bore of the rivet 8 to prevent any inward collapse during staking to retain the handle.

In Figure 9B a further modified to tool 23A has an annular channel 23C around the peg 23B, which channel is contoured to direct the radial flow of the rivet material as the rivet shank spreads radially.

In the rivet 8 shown in Figures 3 to 9 the central bore 11 extends down the rivet shank 10 from the free end of the latter, and has its blind end located at approximately the junction of the shank 10 with the rivet head 9.

In contrast, in the rivet of Figures 10 to 12, the bore 11' extends through the head 9 into the shank ]0 and has a blind end which is located within the shank at a distance from the shank free end. The solid portion 30 which is thereby left at the free end of the shank reduces or obviates the need for providing lateral restraint for the shank when, as shown in Figure 11, the rivet is staked to the container 14. Thus the top tool 19 used for this staking operation may have its lower face plain, rather than recessed as shown in Figure 8 to receive the end portion of the shank.

The staking of the shank to attach the handle to the can is effected by a top tool similar to the tool 23 of Figure 9 but with its lower frustoconical surface concave rather than convex.

It will particularly be noted that the rivets of Figures 3 to 9 and of Figures 10 to 12 both have cylindrical shanks 10 of constant diameter. Furthermore, in both rivets, the bore 11 or 11 'extends throughout the part of the shank which is deformed to initially attach the rivet to the container 14.

Various modifications are possible in the method and apparatus used for achieving the staking deformations depicted in Figures 8, 9 and 11, 12. Thus, instead of separate presses a single press with a multi-head turret could be used, in which case it may be convenient to move the anvil against the top tools. Alternatively hand implements could be employed.

The rivets particularly described are preferably made from mild steel for economy, but they may alternatively be made from other known rivet materials such as copper or aluminium.

Although specifically described in relation to the attachment of handles to cans, the invention may be applied to a variety of containers or the like.

WHAT WE CLAIM IS:- 1. A connection wherein a first member is attached to a second, thin walled, member, by means of a stud having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, the hollow portion of the shank being deformed outwardly to form a bulge which, together with the head, grips the second, thin walled, member, and the free end portion of the shank being deformed outwardly to secure the first member pivotably to the second thin walled, member.

2. A connection according to claim 1, wherein the blind bore extends from the free end of the shank towards the head.

3. A connection according to claim 1, wherein the blind bore extends through the head towards the free end of the shank and terminates short of said free end.

4. A method of attaching a first member to a second, thin walled, member by means of a stud having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, comprising inserting the shank through a hole in the second, thin walled, member, engaging the free end portion of the shank with a tool, compressing axially a portion of the shank, which is between the free end portion and the second member, by axial motion of the tool relative to an anvil supporting the stud head to form a bulge which, together with the stud head, grips the second, thin walled, member, fitting the free end portion of the shank through a hole in the first member and deforming the free end portion to secure the first member pivotably to the second member.

5. A method as claimed in claim 4 in which the tool comfines the said free end portion to prevent distortion thereof during said axial compression.

6. A connection, substantially as hereinbefore described with reference to Figures 3 to 6 of the accompanying drawings.

7. A connection substantially as hereinbefore described with reference to Figures 10 to 12 of the accompanying drawings.

8. A method of fixing a handle on a wall of a can, substantially as hereinbefore described with reference to Figures 3 to 12 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. have cylindrical shanks 10 of constant diameter. Furthermore, in both rivets, the bore 11 or 11 'extends throughout the part of the shank which is deformed to initially attach the rivet to the container 14. Various modifications are possible in the method and apparatus used for achieving the staking deformations depicted in Figures 8, 9 and 11, 12. Thus, instead of separate presses a single press with a multi-head turret could be used, in which case it may be convenient to move the anvil against the top tools. Alternatively hand implements could be employed. The rivets particularly described are preferably made from mild steel for economy, but they may alternatively be made from other known rivet materials such as copper or aluminium. Although specifically described in relation to the attachment of handles to cans, the invention may be applied to a variety of containers or the like. WHAT WE CLAIM IS:-

1. A connection wherein a first member is attached to a second, thin walled, member, by means of a stud having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, the hollow portion of the shank being deformed outwardly to form a bulge which, together with the head, grips the second, thin walled, member, and the free end portion of the shank being deformed outwardly to secure the first member pivotably to the second thin walled, member.

2. A connection according to claim 1, wherein the blind bore extends from the free end of the shank towards the head.

3. A connection according to claim 1, wherein the blind bore extends through the head towards the free end of the shank and terminates short of said free end.

4. A method of attaching a first member to a second, thin walled, member by means of a stud having a head and a shank which is of constant external diameter and which is formed with a blind bore so that a portion of the shank adjacent to the head is hollow, comprising inserting the shank through a hole in the second, thin walled, member, engaging the free end portion of the shank with a tool, compressing axially a portion of the shank, which is between the free end portion and the second member, by axial motion of the tool relative to an anvil supporting the stud head to form a bulge which, together with the stud head, grips the second, thin walled, member, fitting the free end portion of the shank through a hole in the first member and deforming the free end portion to secure the first member pivotably to the second member.

5. A method as claimed in claim 4 in which the tool comfines the said free end portion to prevent distortion thereof during said axial compression.

6. A connection, substantially as hereinbefore described with reference to Figures 3 to 6 of the accompanying drawings.

7. A connection substantially as hereinbefore described with reference to Figures 10 to 12 of the accompanying drawings.

8. A method of fixing a handle on a wall of a can, substantially as hereinbefore described with reference to Figures 3 to 12 of the accompanying drawings.