GB2035168A - Machine for aiding radiator repairs - Google Patents

Abstract

In place of the traditional soldered connection between the tanks and the core block, some radiators, particularly motor vehicle radiators, are being manufactured with a connection having a rubber gasket 9 which is compressed, and the connection rendered mechanically sound, by bending a series of tabs 15 over onto a ledge (14) on a bead (13) of the tank cover 7. It is so troublesome to dismantle such a connection without damage that such radiators have been discarded rather than repaired. The invention provides a machine in which a tool, Fig. 2 (not shown), traverses along the series of tabs, imparting a twisting motion to the tabs to bend them all back. The tool may be likened, in shape and in action, to a plough, in that only a simple straight line traverse is effective to provide the twisting motion. The traversing may be effected by coupling the tool to a saddle 18 mounted on a lead screw 19 of the machine. <IMAGE>

Description

SPECIFICATION Machine for aiding radiator repairs This invention relates to machines for aiding radiator repairs, suitable for use with radiators of the type described below which are most frequently used in vehicles for cooling the engine water.

Motor vehicle radiators generally comprise a bottom tank, and a top tank, interconnected by a core block of many small bore, finned, tubes, and when it requires repair it is usually necessary to dismantle a tank so as to gain access to the ends of the tubes. Traditionally this operation has involved unsoldering a tank cover, which had been soldered during manufacture of the radiator. It has been found that a different type of junction, other than a soldered one, offers certain advantages in manufacture and reliability, and such a junction requires different techniques for the repair of the radiator.

In the type of radiator to which the machine of the invention is applicable, the tank cover is fixed to the core block by means of a plate which forms part of the core block, the plate is formed with a series of tabs, which are bent around a suitably shaped bead of the tank cover onto a ledge provided on the bead to hold compressed a resilient gasket which renders the joint watertight.

It is possible to bend these tabs back, to dismantle the type of radiator described, using a screwdriver or similar implement. However, such an operation is very time consuming and can lead to damage, even breakage of tabs, so that the radiator cannot be reiliably reassembled after repair. The operation is so troublesome that is has been the normal practice to discard the radiator of the type described, once it has developed a fault. The screwdriver blade will also usually be damaged.

The invention is aimed at providing a machine for aiding the repair of radiators of the type described, by providing means whereby the tabs may be bent back in a controlled manner which tends not to damage the tabs, thus making for reliable reassembly after repair.

According to the first aspect of the invention a machine for aiding repairs to a radiator of the type described comprises a support, work holders mounted on the support for locating the radiator, a tool guided for movement relative to one of the work holders and in a direction such that the tool traverses along the radiator, parallel to the series of tabs and in operative engagement with the ledge of the radiator, the tool having a bladelike tip positioned so as to engage between one of the tabs and the ledge and so arranged that traverse of the tool gives rise to a progressive wedging action which causes the tab to bend gradually and become increasingly parted from the ledge, until the tab is bent quite clear of the ledge, continued traverse being effective to bend back a plurality of tabs.

The clamping force applied by the tabs may be substantially relieved by a clamp mounted on the support, and adapted to hold the radiator firmly in the work holders and also to compress the resilient gasket of the radiator.

With the machine of the invention, only a simple traversing motion is required; it is not necessary to provide a complex pulling and indexing type of motion.

The tool of the invention may be likened in its shape and action to an agricultural plough, in that a simple straight line motion is caused, by the shape of the tool, to impart the twist required to bend the tabs.

The tool may be so shaped as to have a flat bottom surface, which sweeps along the ledge during traverse of the tool, and to have a working surface, inersecting the bottom surface, and so arranged that the angle between the working surface and the bottom surface where the surfaces intersect increases progressively with distance away from the tip along the line of intersection from a value at the tip which is as near zero as is commensurate with the strength of the material of the tool, to a value at some distance from the tip which is a little more than a right-angle.

Preferably, the working surface is arranged so that the said relationship of angles applies only to that part of the working surface that is in the region of the intersection between the working surface and the bottom surface; away from the bottom surface, the working surface may be curved in a concave sense, for the purpose of enhancing tool strength and to ensure a smooth, controlled movement of the tab as it is bent by the tool during its traverse.

Usually, the tabs are rectangular in shape, the side edges being straight and at right angles to the direction of motion of the tool.

One of these side edges faces the approaching tool.

Preferably the blade-like tip of the tool is so dimensioned and arranged that the tip only engages towards the free edge end of the tool-facing side edge, and not the root end of that side edge. The blade-like tip thus extends right up to the free edge end of the toolfacing side edge, but the tool is relieved or cut away so that the blade-like tip does not at first engage the root end of the tool-facing side edge.

According to a second aspect of the invention a method of removing the tank cover from the core block of a radiator of the type described comprises traversing a mechanically guided tool along the radiator so as to lift the tabs in turn from the ledge.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view, partly in section, of a machine constructed in accordance with the invention, and shown in conjunction with a vehicle radiator; Figure 2 is a close-up view showing the relationship of part of one tool of the machine of Fig. 1 to the radiator, lines being drawn on the working surface of the tool to indicate its shape;; Figure 3 is a section on line 3-3 of Fig. 2, and showing the whole tool.

The machine for aiding radiator repairs shown in Fig. 1 comprises a sturdy fixed framework (not shown) upon which is mounted a pair of work holders 2, 3. The work holders 2, 3 are fixed during operation of the machine, but may be adjustable to accomodate different sizes of radiator. Vertical clamp 4 also mounted in the framework, is constrained for movement vertically, and is operated by a pneumatic cylinder (not shown).

The radiator 5, to be repaired, comprises a core block 6, and a tank cover 7. The core block 6 comprises many aluminium tubes (not shown) which are disposed vertically, their upper ends being located in holes (not shown) formed in a tube plate 8, and sealed, against leakage of the water to be contained in the radiator, by being passed through correspondingly tightly fitting holes in a resilient gasket 9, which lies flush with, and on top of the tube plate 8.

To render the joint between the tubes of the core block 6 and tank cover 7 mechanically sound and watertight, the tube plate 8 is bent several times to form a peripheral trough, first downwards to form a spacing abutment 10, then horizontally to form a cover rest 11, then upwards to form a retaining wall 12. The gasket 9 is so arranged as to follow these bends, but to terminate at the bend between the cover rest 11 and the retaining wall 12.

The cover 7 is formed around its periphery with an outwardly directed bead 13 which is snugly received in the trough, the upper edge of the bead 13 defining a flat ledge 14.

The joint is completed, during the initial manufacture of the radiator 5, by bending inwards several tabs 15 which depend from the free edge of the retaining wall 12, until the tabs 15 are all bent fully down onto the ledge 14 to compress a marginal band of gasket 9 to effect a watertight seal between the bead 13 of tank cover 7 and the tube plate 8.

The machine of Fig. 1 provides a means whereby the tabs 15 may be released from the ledge 14, thus allowing the cover 7 to be released from the core block 6, and allowing access to the gasket 9 and the tube plate 8 for repair. Various methods for repairing radiators of the type described are set forth in the Complete Specification of our U.K. Patent Application No. 7925/78.

The work holders 2, 3 are formed with longitudinal rebates 16, dimensioned to receive loosely the retaining wall 12 and the outer part of cover rest 11 of the tube plate 8.

When the clamp 4 is in its operative position, it exerts a downward force on the cover 7, which force is reacted through the gasket 9 and the cover rest 11 to the rebate 16. The clamping force is sufficient to compress the gasket (a force of about 10 kN is typical) and at the same time to hold the tube plate 8, and with it the core block 6, firmly in the work holders 2, 3.

The clamping force, furthermore, is sufficient to compress the gasket 9 to such an extent that a slight gap is created between the under surfaces of the tabs 15, and the ledge 14.

The work holders 2, 3 are each formed with a dovetail slide 17 in which a respective saddle 18 is guided for horizontal movement parallel with the retaining wall 12. A respective lead screw 19 passes through each saddle 18, and is selectably engageable (in a manner not illustrated but commonly used in machine tool practice) with a nut (not shown) forming part of the saddle 1 8. It is arranged that operation of a respective handle 20 is effective to engage and disengage the nut from the lead screw 19. Each lead screw 19 is connected to an electric motor, and rotates continuously whilst the machine is in use.

Each lead screw 19 is mounted in bearings (not shown) in the framework of the machine, which constrain it firmly against all movement other than rotation about its axis.

Pivoted to each saddle 18 about a hinge pin 21 is a respective tool holder 22. The tool holder 22 is constrained against movement relative to the saddle 18 in a direction parallel to the lead screw 19, by virtue of its location within a slot 23 formed in the saddle 18.

Each tool holder 22 carries a tool 24, which acts, in traversing along the cover 7, to bend back the tabs 15 of the tube plate 8.

Fig. 2 shows the tool 24 and illustrates its shape in relation to its direction of motion and to the tabs 15.

The tool 24 has a blade-like tip 26, a flat bottom surface 27, and a working surface 28, these two surfaces intersecting, and defining an angle at their intersection. This angle is almost zero in the region of the tip 26 (not quite zero, of course, for the tip must have a real thickness, commensurate with the strength of the material, but near enough to zero for the tip 26 to be regarded as bladelike). As can be seen from the lines 29 drawn on the surface 28 in Fig. 2, the angle between the two surfaces 27, 28 where they intersect increases with distance away from the tip 26, gradually becoming a right-angle, and then slightly more than a right-angle, so that the bent-back tabs interfere not at all with subsequent removal of the cover 7.

The tool 24 is formed from an integral block and includes an upper portion 30. A side 31 of the tool 24 merges with the working surface 28, and is formed at about 100 to the bottom surface 27. That part of the side 31 which extends to the upper portion 30 is cemented to the tool holder 22, the latter being relieved so as to form a slot 32 through which a bent back tab 15 may pass.

The tool 24 traverses in the direction of arrow 25. The tabs 15 are rectangular and have a root 34, a free edge 35, and two side edges 36, 37, one 36 of which faces the approaching tool 24. The tip 26 engages between the ledge 14 and that end of the side edge 36 is towards the free edge 35.

The tool 24 is relieved or cut away as at 38 so as not to engage the root 34 end of the side edge 36. Subsequent traversing serves to bend the whole tab back to the position of tab 15b. The bent back tab 15b emerges from the slot 32 between the tool and the tool holder. As a tab 15 is being bent back, it exerts a downwards force on the tool 24, which serves to hold the tool 24 firmly against the ledge 14.

To dismantle the radiator, the tools 24 are positioned at one end of the radiator, each lead screw 19 is engaged to the saddle 18 by operation of the handle 20, and each tool 24 traverses along, bending back the tabs 15 as it goes. Sometimes, an obstruction is encountered, for example in the form of a hose connection provided in the cover 7. (Normally, the radiator is not provided with tabs underneath such an obstruction, as it would have been difficult to bend these tabs during manufacture of the radiator). The tool holder 22 may be pivoted around hinge pin 21, to clear such an obstruction.

When there are one or two further tabs on the ends of the radiator, and it is inconvenient to set the radiator in the machine just for these few tabs, they may be bent back by means of a handtool, shaped like the tool used in the machine of the invention, but tapped along the tabs by means of a hammer.

After any leaks in the core block 6 have been repaired the machine is used to recompress the gasket 6, and the tabs are bent back to their original positions to complete the repair of the radiator.

Claims (14)

1. A machine for aiding repairs to a radiator of the type described, comprising a support, work holders mounted on the support for locating the radiator, a tool guided for movement relative to one of the work holders and in a direction such that the tool traverses along the radiator, parallel to the series of tabs and in operative engagement with the ledge of the radiator, the tool having a bladelike tip positioned so as to engage between one of the tabs and the ledge and so arranged that traverse of the tool gives rise to a progressive wedging action which causes the tab to bend gradually and become increasingly parted from the ledge, until the tab is bent quite clear of the ledge, continued traverse being effective to bend back a plurality of the tabs.

2. A machine as claimed in claim 1 in which the tool has a flat bottom surface adapted to sweep along the ledge during traverse of the tool, and a working surface intersecting the bottom surface, so arranged that the angle between the working surface and the bottom surface wherein the surfaces intersect increases progressively with distance away from the tip along the line of intersection, from a value at the tip which is as near zero as is commensurate with the strength of the material of the tool, to a value at some distance from the tip which is a little more than a right-angle.

3. A machine as claimed in claim 2 in which the working surface is arranged so that the said relationship of angles applies only to that part of the working surface which is in the region of the intersection between the working surface and the flat bottom surface.

4. A machine as claimed in claim 3 in which part of the working surface remote from the intersection with the flat bottom surface is curved in a concave outwards sense.

5. A machine as claimed in any of claims 2, 3 or 4 in which the working surface remote from the tip merges smoothly with a flat side of the tool, the side forming an angle of substantially 1 00, to the flat bottom surface.

6. A machine as claimed in any of the preceding claims in which the tip is so relieved as to contact first a side edge of a tab at a position adjacent to the free end of the tab.

7. A machine as claimed in any of the preceding claims, in which the tool is mounted in a saddle, and the saddle is guided for sliding with respect to one of the work holders, a lead screw being operative to cause the sliding movement.

8. A machine as claimed in claim 7, in which the saddle includes a nut which is selectably engageable with the lead screw.

9. A machine as claimed in claim 7, in which the saddle is guided for sliding in a dove-tail shaped guide in the work holder.

10. A machine as claimed in any of the preceding claims including a clamp mounted on the support and adapted to hold the radiator firmly in the workholders and also to compress the resilient gasket of the radiators.

11. A machine for aiding repairs to a radiator of the type described, contructed and adapted to operate substantially as described with reference to the accompanying drawings.

12. A method of removing the tank cover from the core block of a radiator of the type described comprising traversing a mechani cally guided tool along the radiator so as to lift the tabs in turn from the ledge.

13. The method of claim 11 and substantially as described herein.

14. A radiator of the type described which has been repaired by the method claimed in claim 12 or 13.