GB1568676A - Process for making a metal annular blank - Google Patents

Description

PATENT SPECIFICATION

( 11) 1 568 676 ( 21) Applicatioh No 14982/79 ( 22) Filed 7 Oct 1976 ( 19) ( 62) Divided Out of No 1 568 675 t 31) Convention Application Nos 622 269 ( 32) Filed 14 Oct 1975 691 720 1 June 1976 in ( 33) United States of America (US)I ( 44) Complete Specification published 4 June 1980 ( 51 i) INT CL " B 21 D 53/16 ( 52) Index at acceptance B 3 A 122 J 85 ( 54) PROCESS FOR MAKING A METAL ANNULAR BLANK ( 71) We, THE GENERAL TIRE & R UnBE Rt COMPANY, a corporation organized and existing under the laws of the State of Ohio, of One General Street, Akron, Ohio, United States of America, do hereby deelare this 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 fol-

lowing statement:-

This invention relates to a process for making a metal annular blank having a desired surface finish, and to blanks made by the process.

IS Suspension systems, particularly those suspension systems found in automotive applications make substantial use of devices commonly known as bushings.

Generally, these bushings consist of at least two more or less concentric annular mfnembers, usually of metal, separated by a rubber element of specific design which element is under compression Such devices are sometimes called outer and inner metals or "outers" and "inners" and are more fully described in, for example, U S Patent Nos 3,893,7 '75; 3,495,859; and 3,199,186.

In certain bushings it is desirable or necessary that the surface of the outer or inner which contacts the rubber element be so configured or finished as to grip the rubber element so as to eliminate or reduce slippage therebetween One prior art procedure for preventing relative movement between the metal sleeves and the elastomerlc insert is disclosed in Sievers patent 893,775 and involves sandblasting the surfaces of the metal sleeves and thereafter formning a phosphate coating thereon It O is desirable that improved means be provided for forming a rough gripping surface on the metal sleeves of the bushing It is desirable that better control over the precise form of the surface texture be provided and that this be accomplished inexpensively Other prior art related to this feature are U S patents 1,94 O,302 to Huumphre; 1,959,256 to Zerk: 2,725,692 to Andreae; 2,819,105 to Belinke; 3 368,852 to Hlerbenar; and 3,504,513 to Black.

Our patent application No 41,771/76 (Serial No 1,568,675) of which this application is a divisional describes and claims processes and apparatus for die forming annular metal blanks, e g blanks made ac 55 cording to the present invention.

According to the present invention, there is provided a process for making a metal annular blank which comprises moving flat sheet metal between a pair of parallel rollers 60 which are maintained in spaced relation to one another and roll against the sheet metal and are shaped to deform both surfaces of the sheet metal into a desired surface texture, skelping the sheet metal, and connect 65 ing opposite edges thereof to form a tubu lar sheet metal member.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in 70 which: Figure 1 is a schematic perspective view of a surface preparation procedure embodying the present invention; Figures 2 and 3 are perspective views of 75 an annular blank and a shaped annular member having a surface treatment provided according to the present invention; Figure 4 is a fragmentary perspective view of an annular member having an em 80 bossed grid configuration provided by a process embodying the invention on its surface; Figure 5 is an enlarged fragmentary cross section of the sheet metal 205 after 85 it has passed through the rollers 2 { 1 of Figure 1; Figure 6 is an enlarged fragmentary 'crosssection of the rollers 201 of Figure 1, showing the surface configuration thereof; and 90 Figure 7 is a schematic side elevation of a tube mill having a surface texturing device for applying surface texturing according to the present invention combined therewith 95 Referring to Figure 1, there is illustrated a coil 200 of sheet metal which is drawn through rollers 201 by suitable drive means (not shown) The rollers 201 and the drive means may be a part of a conventional 100 1,568,676 reduction mill, the usual function of which is to reduce the thickness of sheet material down to precise thickness The rollers 201 may be a part of a tube mill which forms sheet into tube The rollers 201 have longitudinal grooves 202 and projections 203 (see Fig 6) in their external surfaces, which are forced into the sheet metal 205 as the rollers rotate and the sheet metal moves through the rollers producing longitudinal projections 208 and grooves 206 respectively (see Fig 5) in the sheet metal 205 These longitudinal projections and grooves remain in the sheet metal as it is formed and welded into the tubular configuration 207 by a longitudinal butted joint 210.

Annular blanks such as the blank 211 of Figure 2 are obtained from the tubular member 207 The blank 211 can be shaped into the formed annular member 212 of Fig.

3 by for example the procedure described in application No 41,771/76 (Serial No.

1,568,675) Prior to curling the flat sheet 205 into the tubular configuration 207, it may be necessary to trim the edges of the sheet metal so that the tube has the proper diameter On the other hand, even in a reduction mill the reduction in thickness of the sheet metal normally results in a lengthening rather than a widening thereof.

The rollers 201 in one specific embodiment of the invention are designed as an attachment or addition to operate on the sheet metal before it moves into an existing tube mill In designing new tube mills or reduction mills, the rollers 201 can be incorporated into the design of the mill so that the rollers have a double function of reduction to a precise thickness as well as surface texturing.

Figure 5 shows in detail the cross-sectional configuration of the sheet metal after it has passed between the rollers 201 This is one typical texturing which the invention can provide, and the depth, width and configuration of the grooves may vary to provide the result desired; however, in one specific embodiment the grooves 206 are 0060 inches in width and between 0002 and 0005 inches in depth and the projections are of the same width Figure 6 shows in cross-section the die configuration used to produce the surface configuration of Figure 5 This die configuration is constant in cross-section circumferentially It should be understood that the rolls 201 are fixed in a spaced relationship which is the thickness desired for the sheet metal 205.

If the sheet metal from the coil 200 is thicker than the spacing, a substantial force must be exerted on the sheet metal by the rolls 201 which might be, for example, of the order of 50 Tons and can be calculated given the various parameters of the metal.

Thus the structure which holds the rolls in a spaced relationship should be capable of resisting this force.

In some designs of bushings, it is desirable or necessary that there is resistance to 70 slippage between the inner and outer metal sleeves and the elastomeric insert in both the rotary and axial directions, in which case the surface configuration of Figure 4 is desirable The sheet metal 215 has sur 75 faces raised in the form of grids 216, one on each side, including a series of square recesses 217 which are produced by rollers identical to 201 except that their external configuration is not constant in cross-sec 80 tion circumferentially but instead includes a series of projections of mating configuration to the recesses in the surface of the sheet metal 215 Thus Figure 6 is also an appropriate cross-sectional representation 85 for the regions of the rollers which produce the configuration of Figure 4.

Figure 7 shows in more detail a tube mill having means for performing the present invention incorporated therein A stan 90 dard uncoiler 225, which might be, for example, a Single Coil Cradle manufactured by McKay Division of Wean Industries of Youngstown, Ohio, uncoils the sheet metal and feeds it into a standard strip splicer 95 226 and collector unit which might be, for example, an MPM strip joining shear welder made by the same company and including an accumulator 227 The rollers 201 of Figure 1 are represented in Figure 7 by 100 rollers 230 and 231 The roller 230 is driven and rotatable, and its axis is fixed.

The roller 231 is vertically adjustable by the hydraulic motor 228, but its axis can be fixed in a desired spaced relationship to 105 the roller 230 by the frame 229 The surfaces of the rollers 230 and 231 have the appropriate configuration to produce the texturing desired 206 or 216 or any other desired texturing such as, for example, an 110 nular lines, diagonal cross hatch or diamond design patterns, longitudinal parallel waved lines, and/or a simulated phosphated surface The structure 228-231 will not be described in greater detail because it is a 115 standard cold reduction mill except for the particular surface of the rollers 230 and 231 An example of such a cold reduction mill is a Fenn Rolling Mill manufactured and sold by Fenn Manufacturing Company 120 of Newington, Connecticut.

The large loop 235 of sheet metal is used to control the relative speed of the driven roll 230 and the tube mill 236 Two electric eyes, not shown, are located one 125 above and one below the loop 235 and function to slow down or speed up the roll 230 The tube mill 236 is, for example, a 400 series McKay Tube Mill with cut off also manufactured by McKay Division of 130 z 1,568,676 Wean Industries The function of the tube mill and welder is to gradually skelp the sheet metal until the opposite edges thereof meet whereupon they are welded together.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same are to be considered as illustrative and not restrictive in character.

Claims (4)

WHAT WE CLAIM IS:-

1 A process for making a metal annular blank which comprises moving flat sheet metal between a pair of parallel rollers which are maintained in spaced relation to one another and roll against the sheet metal and are shaped to deform both surfaces of the sheet metal into a desired surface texture, skelping the sheet metal and connecting opposite edges thereof to form a tubular sheet metal member.

2 A process according to claim 1, wherein said rollers have a constant crosssection circumferentially and are configured to produce grooves in said sheet metal.

3 A process according to claim 1, wherein said rollers are configured to produce a plurality of recesses separated by a raised grid pattern in said sheet metal.

4 A process for making a metal annular blank substantially as any herein described with reference to the accompanying drawings.

A metal annular blank produced by a process according to any one of the preceding claims.

MEWBURN ELLIS & CO, Chartered Patent Agents, 70-72 Chancery Lane, London WC 2 A l AD.

Agents for the Applicants.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon), Ltd -1980.

Published at The Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.

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