GB2313077A - Apparatus to manufacture a casing - Google Patents

Abstract

Apparatus to manufacture a casing, particularly a silencer box for a motor vehicle, comprises a rotatable support (28, Fig.2) to receive an end plate with a side wall having an end edge abutting the periphery of the end plate, deforming rollers 29, 30 to contact the end plate and side wall so as to deform same in cooperation with the support to form a joining seam, a rotatable profile cam 20 and cam followers 18, 19 and drive means to rotate the support 28 and cam 20 synchronously. The cam followers 18, 19 and deforming rollers 29, 30 are carried on pivotally mounted arms 10, 11 at respective opposite sides of the pivot thereof. The arms 10, 11 are linearly adjustably movable on a nut and screw mechanism 12, 13, 14 and the cam followers 18, 19 are carried on levers 16, 17 pivotally mounted on the arms and actuatable by a piston and cylinder mechanism 22, 23, 24, 25.

Description

APPARATUS TO MANUFACTURE A CASING This invention relates to apparatus to manufacture a casing, particularly a metal casing in the form of a silencer box or muffler of a motor vehicle exhaust system.

Machines are known which.aid in the manufacture of muffler bodies, one such machine employing a support which carries the end wall of the muffler as well as its usually cylindrical or elliptical longitudinal wall. A deforming roller is then brought into contact with the end of the longitudinal wall and the edge of the end wall, in use, to form a seam joining the two walls together.

The deforming roller is mounted for movement on a pivoted arm so that it can follow the shape of the outer periphery of the longitudinal wall and of the end wall, even if this is oval or elliptical. Movement of the arm is conveniently controlled through a cam follower which is in engagement with a cam track on a rotatable cam, the profile of the cam track generally corresponding to that of the walls of the muffler parts to be joined.

In one prior art machine, the cam has an internal cam track with which two cam followers are engaged, an upstanding linkage mechanism being provided with each cam follower to translate the movement of the cam follower, as the cam rotates synchronously with the support, into corresponding movement of the deforming roller on a pivoted arm raised above the cam, so that each of the rollers remains in contact with the muffler parts to form the seam as the support rotates.

A major disadvantage of this prior art machine is that it has no means for compensating for wear on the cam or deforming rollers. Additionally it is a relatively difficult and time consuming process to change various components of the machine if a different size of muffler is to be seamed, particularly as such components are relatively heavy.

European Patent Specification No. 0100687 relates to a further prior art machine of the general type described above. Here two cams are used instead of a single one, each having an external cam track. There is again no means for compensating for wear on the cams or deforming rollers and although the cams can be changed to provide different profiles to suit the muffler to be formed, there is no provision for a significantly larger cross-section muffler to be seamed using the one machine. The machine also suffers from side pressure on the spindle bearings as a result of unequal pressure on the sides of each cam, and twisting forces are generated between a cam and its associated deforming roller due to them being in different horizontal planes.

An object of the invention is to provide apparatus to manufacture a casing in an improved form.

According to a first aspect of the invention, apparatus to manufacture a casing having a side wall with an end thereof being defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprises a rotatable support intended to receive said end plate with said side wall having said edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a rotatable profile cam and cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, said cam follower being carried on pivotally mounted arm means, drive means to rotate the support and the cam synchronously, and the cam follower and the deforming roller respectively, and/or the cam and the support respectively being at opposite sides of the pivot of the arm means.

According to a further aspect of the invention, apparatus to manufacture a casing having a side wall with an end thereof being defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprises a rotatable support intended to receive said end plate with said side wall having said edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a rotatable profile cam and cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, drive means to rotate the support and the cam synchronously, and adjustment means for moving the cam follower and/or the deforming roller towards or away from the cam and/or the support.

The adjustment movement can be to compensate for wear or to allow manufacture of a different size and/or profile of casing.

According to a still further aspect of the invention, apparatus to manufacture a casing having a side wall with an end thereof being defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprises a rotatable support intended to receive said end plate with said side wall having said edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a single rotatable profile cam, a cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, drive means to rotate the support and the cam synchronously, and said single cam having an external cam track.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic view of parts of apparatus to manufacture a casing constructed according to the present invention; and Figure 2 is a part cross-sectional view on the line A-A of Figure 1.

The apparatus of this invention is of the same general form as that described in above mentioned European Patent Specification No.

0100687 and is intended to be used to produce a seam by joining a side wall to opposite end plates of a muffler or silencer box of the form described therein. Moreover apparatus of this invention has various arrangements in common with that described in the European Patent Specification and these will thus not be described in detail. In essence the only important parts of apparatus of the present invention which differ from the apparatus described and shown in the European Patent Specification are those illustrated in Figures 1 and 2.

Accordingly as before, apparatus of this invention is designed for use with a muffler or silencer box consisting of two generally parallel spaced co-extensive end plates which are joined by a generally cylindrical side wall which can be of circular or oval configuration in transverse crosssection. The end plates are secured to the side wall by wrapping the extremities of the side wall about the periphery of the end plates. The side wall is normally formed of sheet metal, as are the end plates.

Moreover the side wall adjacent its extremities can diverge outwardly so as to be generally funnel shaped, and the end plates may be concave inwardly relatively to the side wall so that each end plate has a peripheral flange to engage the periphery edge of the side wall.

Figure 1 shows apparatus constructed in accordance with the present invention to form a seam at the junction of each end plate and side wall.

The apparatus includes a main frame (not shown) with a moveable upper sub-frame as with the aforementioned prior art device. A base of the main frame and also the sub-frame are each provided with deforming assemblies which engage the muffler end plates and side walls so as to cause deformation of their extremities to secure the side wall and end plates together. These upper and lower deforming assemblies are identical and vertically aligned. Accordingly only one of these assemblies will be described in detail. A suitable driving mechanism is provided for driving the lower deforming assembly and for transmitting said drive to the upper assembly.

As shown in Figure 1 the deforming assembly includes a pair of straight arms 10, 11 respectively. The arms are generally centrally pivoted on internally threaded adjustment nut elements 12, 13 respectively, the nut elements being spaced apart on an externally threaded rod 14 which is rotatable by a handle 15 to move the nut elements together or apart along the rod.

The arms have at one of their ends respectively pivotally mounted levers 16, 17, the ends of which are cranked in opposite directions. At the cranked ends of the levers furthest from the arms, are rotatably mounted rollers 18, 19 respectively which, in use, engage a cam track 20 defined by the exterior surface of a rotatable profiled cam 21, the pivots of the arms, the shafts carrying the rollers and the cam all being parallel.

Accordingly the rollers 18, 19 constitute cam followers. The other cranked ends of the levers are pivotally connected to respective ends of piston rods 22, 23 of hydraulic cylinders 24, 25 respectively pivotally connected at respective ones of their ends to brackets 26, 27 carried on the arms. Although not shown, a compression spring can be provided between the arms to bias the cam followers into engagement with the cam track defined around the outside of the profiled cam.

As can be seen from Figure 1, the respective pivots of the two arms on the nut elements are aligned along the axis of the rod 14, and this can be considered to define the centre line of the apparatus, the parts thereof above this line having now been described. At the other side of said line, and thus there below, is provided a rotatably mounted support 28.

Like the cam 21, the support 28 is also profiled, and in the embodiment shown in Figure 1, the profiles of the two members are identical, namely oval, but with the major axis of the cam being aligned with the minor axis of the support. It will be appreciated that any other profile could instead be used, including circular, for the cam and support. Both the cam and the support are rotatable about their respective centres, and the direction of their rotation is preferably as shown by the arrows in Figure 1.

The respective ends of the arms remote from the levers 16, 17, rotatably mount respective deforming rollers 29, 30, these rollers being arranged adjacent the external periphery of the support 28 so that, in use, these rollers can engage the peripheral edge of the muffler side wall where it is engaged by the peripheral flange of the end plate, so as to form a seam as will be described. Figure 2 shows that each deforming roller has a pair of generally circumferential grooves 31, 32 therein, two grooves being provided so that the roller can be used either way up. Each groove is intended to cooperate with a circumferential groove 33 adjacent the end of the support 28 to provide the seam as will be described.

In use an appropriately sized and profiled support is selected and mounted on the base of the apparatus for rotation about its centre. A correspondingly sized and profiled cam is similarly rotatably mounted on the base. The arms 10, 11 can then be moved into position, substantially as in Figure 1, by rotation of the handle 15 to move the arms together, these having been sufficiently spaced apart to allow fixing of the support and cam in place.

Initially the rollers 18, 19 engage the cam track by virtue of the bias of the spring between the arms. However, in this position there is clearance between the deforming rollers and the adjacent exterior surface of the support in order to allow positioning on the support of the muffler parts to be joined together. Accordingly the muffler end plate is located on the support, with its concave surface, if appropriate, downwardly, with the side wall being placed on the end plate so as to extend upwardly therefrom. Accordingly the flange peripheral edge of the end plate and the peripheral edge of the side wall are in abutting relationship. Once the muffler parts are in position, the hydraulic piston and cylinder units are each actuated to extend the rods thereof, and this causes the respective arms 10, 11 to pivot slightly to bring the deforming rollers 29, 30 into engagement with the muffler parts where the seam is to be produced, whilst the rollers 18, 19 still remain engaged on the cam track 20.

The diverging end of the side wall and the flanged peripheral edge of the end plate are sandwiched between the rollers 29, 30 and the support 28 so that the edge of the side wall and the flanged edge of the end plate are both located facing the upper groove 31. The cam and support are then driven synchronously at the same angular velocity in the directions shown in Figure 1. The rollers 18, 19 move inwardly and outwardly upon rotation of the cam and this movement causes a pivoting of the arms so that the deforming rollers 29, 30, follow the general outline of the muffler to be formed as defined by the profile of the cam track, so that the rollers 29, 30, retain their engagement with the parts of the muffler to be joined together. Thus the edge of the side wall and the peripheral flange of the end plate are caused to fall back upon themselves to be rolled together to form a seam along the edge of the casing. By a similar simultaneous operation at the upper sub-frame of the apparatus, the other end plate of the muffler is similarly secured by a seam to the side wall of the muffler.

Although described with two cam followers and two deforming rollers, it will be appreciated that only one of each of these is necessary if at least a full 360" rotation of the cam and the support is carried out. Moreover instead of an external cam track, this could be internal, although this is not preferred in that an equivalent cam with an internal cam track would be larger and heavier than one defining an external cam track.

By providing the cam and the support, and also a cam follower and associated deforming roller at respective opposite sides of the arm pivot, apparatus is provided which is much improved over the prior art machines in requiring only a single cam, being relatively compact and of lighter construction. Additionally the apparatus of the invention has various advantages as compared to the prior art machines.

Firstly each cam follower roller and its associated deforming roller are in the same horizontal plane, as shown in Figure 2, thereby avoiding a twisting force between these two components which is present with the prior art machines. Secondly pressure on both sides of the cam is equal, with the result that there is no side pressure on the spindle bearing of the cam. Thirdly the apparatus provides means for compensating for wear on the cam assembly and/or deforming rollers merely by rotation of the handle 15. It is also possible to use re-machined forming rollers. Finally as described herein, the adjustment provided enables the same machine to be capable of use with a much greater range of sizes of muffler, and in particular the apparatus of the present invention is able to be used with large mufflers, for example those used with large trucks. Present machines are capable of use with a maximum muffler size of 30.48 cm (12 inches), whereas apparatus of the present invention can handle mufflers from 7.62 cm (3 inches) to 45.72 cm (18 inches).

Many variations are possible from the embodiment described and illustrated herein. For example instead of a single arm effectively carrying the cam follower and deforming roller, these could be carried by two separate individual pivoted members provided that the pivotal movement of the member carrying the cam follower is translated into corresponding movement of the member carrying the deforming roller.

Instead of a common adjustment, the adjustment of the cam followers could be separate from the adjustment of the deforming rollers, or alternatively each cam follower and its associated adjusting roller could be adjustable separately.

Claims (21)

1. Apparatus to manufacture a casing having a side wall with an end thereof defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprising a rotatable support intended to receive said end plate with said side wall having the edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a rotatable profile cam and cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, said cam follower being carried on pivotally mounted arm means, drive means to rotate the support and the cam synchronously, and the cam follower and the deforming roller respectively, and/or the cam and the support respectively being at opposite sides of the pivot of the arm means.

2. Apparatus as claimed in Claim 1, comprising a single cam having an external cam track followed by said cam follower, in use.

3. Apparatus as claimed in Claim 2, wherein the cam follower is pivotally carried on said arm means.

4. Apparatus as claimed in Claim 3, wherein the cam follower is carried on a lever pivoted on the arm means, the lever being connected to a piston of a piston and cylinder arrangement carried by the arm means.

5. Apparatus as claimed in any one of Claims 1 to 4, wherein the arm means is adjustably movable towards and away from said cam.

6. Apparatus as claimed in Claim 5, wherein the arm means is linearly movable.

7. Apparatus as claimed in Claim 6, wherein the arm means is pivotally mounted on an internally threaded nut element which is engaged on an externally threaded rod, so that, in use, rotation of the rod moves the nut element, and thus the arm means, linearly therealong.

8. Apparatus as claimed in Claim 4, wherein the arm means is adjustably movable towards and away from said cam, the cam follower being arranged initially to engage the cam upon such adjustment movement with there being clearance between the deforming roller and the support, such clearance being taken up upon a pivoting of the arm means effected by actuation of said piston and cylinder arrangement.

9. Apparatus as claimed in any one of the preceding claims, wherein the arm means is a straight arm.

10. Apparatus as claimed in any one of the preceding claims, wherein the cam follower and cam are at one side of the pivot of the arm means, and the deforming roller and the support are at the opposite side of the pivot of the arm means.

11. Apparatus as claimed in any one of the preceding claims, wherein a line through the respective axes of the cam and the support defines a centre line of the apparatus, about which it is generally symmetrical, having a second arm means, second cam follower and second deforming roller arrangement, identical to said arm means, cam follower and deforming roller, and disposed as a mirror image thereof at the opposite side of said centre line.

12. Apparatus as claimed in Claim 11, wherein said arm means and said second arm means are interconnected by means of a common externally threaded shaft on which respective internally threaded nut elements are engaged, said arm means and said second arm means being pivotally carried on said nut elements respectively.

13. Apparatus as claimed in Claim 11 or Claim 12, wherein the arm means and the second arm means are interconnected by spring means which bias said cam follower and said second cam follower into engagement with said cam at opposite positions thereof.

14. Apparatus as claimed in any one of Claims 11 to 13, comprising a further rotatable support disposed above and spaced from said rotatable support, and in alignment therewith, there being means for transmitting drive from said drive means to said further rotatable support and a further synchronously driven cam, so that simultaneously with the production of said seam at one end of the casing, a further seam is produced at the opposite end thereof in the same manner.

15. Apparatus to manufacture a casing having a side wall with an end thereof being defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprising a rotatable support intended to receive said end plate with said side wall having said edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a rotatable profile cam and cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, drive means to rotate the support and the cam synchronously, and adjustment means for moving the cam follower and/or the deforming roller towards or away from the cam and/or the support.

16. Apparatus as claimed in Claim 15, wherein the adjustment movement of the cam follower and/or the deforming roller is by means of a nut and screw adjustment mechanism.

17. Apparatus as claimed in Claim 16, wherein the cam follower is carried by pivoted arm means which is linearly adjustably movable.

18. Apparatus as claimed in Claim 17, wherein the cam follower is carried on a lever which is pivotally mounted on said arm means.

19. Apparatus as claimed in Claim 18, wherein the pivotal movement of the lever is controlled by a piston and cylinder mechanism.

20. Apparatus to manufacture a casing having a side wall with an end thereof being defined by an edge of the side wall, and an end plate to close said end by being joined to said edge by a seam, comprising a rotatable support intended to receive said end plate with said side wall having said edge thereof in abutting relationship with the periphery of said end plate, a deforming roller to contact said end plate and side wall so as to deform same in cooperation with said support to form said seam, a single rotatable profile cam, a cam follower, said cam follower being operatively coupled to said deforming roller so that said deforming roller is moved in accordance with the profile of said cam, drive means to rotate the support and the cam synchronously, and said single cam having an external cam track.

21. Apparatus to manufacture a casing substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.