US1940850A - Joining layers of sheet metal - Google Patents

Description

Dec. 26, 1933. A N DERBY 1,940,850

JOINING LAYERS 0F SHEET METAL Filed Sept. 27, 1927 2 Sheets-Sheet l BY f QM ATTORNEY Dec. 26, 1933. N. 1 DERBY JOINING LAYERS OF SHEET METAL Filed sepi. 27,

1927 2 Sheets-Sheva?l 2 WM/QQ ATTORNEY Patented Dec. 26, 1933 PATENT OFFICE s JOINING LAYERS F SHEET METAL Norman L. Derby, Long Island City, N. Y.

Application September 27, 1927 Serial N0. 222,389

9 claims. (ci. zei-189) 'I'he general object of my present invention is to provide an improved method of and apparatus 'for j producing a laminated sheet structure composed of superposed layers of sheet material.l More specifically,

l to provide an improved method of and apparatus for producing laminated sheet stock from which spacing devices such as'bearing shims, washers and analogous devices are cut or stamped. l0 Spacing devices of this type arev characterized by the ease in which the thickness of the article may be reduced by stripping one or more layers from the mass without affecting the relative positions or the connections between the remaining layers. l5 My improved method is'characterized'by its simplicity, low costV and effectiveness in forming a laminated structure from a single strip of sheet material. The apparatus of my invention' is characterized .by its simplicity.,effectivenessA in operation and the relatively low cost of manufacture. It is further characterized by the small amount of oor space occupied, the relatively low labor cost necessary for theoperation thereof and uniformity of product. y A further object of myinvention is to provide an improved method of uniting a plurality of superposed layers of sheet metalVeither in the form of a single strip creased and folded or a plurality of separate sheets, which is characterized by the elimination of air and gas bubbles between the layers, non-formation of oxides on the surfaces being united and eflicient use of the binder material. y

The various features of novelty whichvcharacterize my invention are pointed out with particularity in the claims annexed to and forming a part/ of this specification. For a better understanding of the invention, however,v and the advantages possessed by it reference should be had `to the accompanying drawings and descriptive matter in which I have illustrated and described preferred embodiments of the apparatus employed. a

Of the drawings: Fig. 1 is perspective of a sheet of yraw material after the initial creasing and folding operations; Fig. 2 is an elevationpartly in section of one embodiment of my apparatus;

Fig. 3 is a section on-the line 3&3 of Fig. 2; Fig. 4 is an enlarged perspective of a portion of the apparatus shown in Fig. 2. j

Fig. 5 isa section on the line 5-5 of Fig. 2; Fig. 6 is an elevation partly in section of the pressure roll apparatus; and y Fig. 'l is an elevation partly in section of a porthe object of my invention is` tion of a modified form of the apparatus shown in Fig. 2.

In the drawings and particularly in Figs. 1 to 6,I have illustrated a preferred embodiment of the apparatus by which my improved method may 00 be performed. In the preferred mode of carrying out my method of manufacture, an elongated sheet A of raw material, preferably of brass or steel .002 or .003 inches in thickness, is creased by a die (not shown) at intervals and folded at the creased portions into the form illustrated in Fig. 1 to give any desired number of layers. 'I'he outer layers A' are made slightly longer than the inner layers A2 for a purpose hereafter described.

The expanded layer structure is cleansed of oil, 7. grease and other foreign material by any suitable process and then dipped into a bath of flux, preferably a solution of zinc chloride. The expanded layers are then placed inv a bath of binder ma` terial where the superposed layers are thoroughly coated with the binder and thereafter subjected to an initial pressing while submerged in the binder bath.

The bath apparatus as shown in Fig. 2 comprises an elongated rectangular receptacle B having vertical side and end walls B and arranged to contain a liquid binder such as molten solder. Mounted on the bottom plate Bz of the receptacle is a substantially I-shaped`platform member D having the lower edge of two of the anges D resting on the bottom plate. In the form shown, semi-circular cut-out portions D2 are arranged at spaced intervals in the lower flanges D' to provide an equal temperature of the solder throughout all `portions of the receptacle. The receptacle B is supported on a plurality of transverse I-beams E which in turn rest on a pair of I-beams E extending substantially the whole length of the receptacle. A row of horizontally spaced vertical burners F is arranged beneath the bottom plate of the receptacle B for maintaining the binder in a molten condition. Each burner receives a mixture of gas and air from a main F' extending along the burner row. The fuel supply to each burner is 1 controlled by a valve Fn located at the base of each burner.

The apparatus for exerting pressure on the superposed layer structure while in the receptacle B comprises a rectangular base plate C supported on the platform member lD and overlapping the ends thereof. The plate C has a U-shapedslot C at each end with the curvedv side of the slot adjacent the corresponding end of the platform member. The layers of metal while in the expanded position shown in Fig. 1 are placed on the plate C and submerged in the molten solder, which preferably consists of lead or a lead alloy. A follower plate G similar in form and size to the plate C is then placed in position on the top layer of the material with the cut-out portions G above and in alignment with the cut-out portions C'.

The pressure apparatus also comprises a pressure plate H of substantially the same dimensions as the plates C and G. A pair of integral vertical anges H extend upwardly at opposite sides of the central portion thereof. A lever L,

I having a yoke L' at one end thereof pivotally connected for vertical movements to the upper end of a swivel pin J, extends above the receptacle B. The pin is formed with a top section J" having parallel triangular sides and having a base resting on the upper end of a bearing stand M secured to the oor. A cylindrical lower pin section J2, depends from the top section J and is arranged for rotation in a socket M in the bearing stand M. The cylindrical section is provided with an annular groove J3 in which the ends of two or more of set screws M2 mounted in the stand M engage to permit rotary but prevent vertical movements of the pin J.

The middle section of the lever L is formed with a boss L2 having a central opening L3 therein. A vertical yoke member H2 engages with the sides of the bosses L2 and is pivoted thereon by a pivot pin` L4 passlng'through corresponding openings in the bosses and yoke member. A link H3 is integrally connected with the base of the yoke H2 and provided with an enlarged horizontally extending cylindrical portion H4 arranged to t between the vertical anges H. A pivot pin H5 passes through an opening in the cylindrical portion and corresponding openings in the anges H'.

As illustrated in Fig. 2, the pressure plate H is moved downwardly to engage with the top surface of the follower plate G and the plates C, G and H are then secured together by bolts K. Each screw threaded bolt is provided with a squared shaft portion K adjacent the hexagonal bolt head K2 and is placed in position inthe U-shaped slots of the plate member with the squared shaft portion engaging the sides of the slot C'. A hand wheel K3 is then threaded on each bolt and rotated to compress the layers of material. The squared shaft acts to prevent the bolt from rotating with the hand wheel. It has been found advantageous to place a rectangular metal washer Q, having a U-shaped cut-out portion Q in one side thereof, between the adjacent end portions of the base plate and follower plate. The washers Q act to limit the compression of the upper plates and to prevent the compression of the metallic layers A beyond a predetermined point. The end bolts K act to hold the various plates in alignment when pressure is exerted by the lever L on the plates and interposed metal layers. When the lever L is moved downwardly to exert pressure on the plate H, the hand wheels K3 are further rotated to exert pressure on the end portions of the plate H. fIhis action may be eliminated if the plate H is of sulicient weight that a uniform pressure is exerted on the superposed layers.

A force screw mechanism S is located at the opposite end of the receptacle B from the swivel joint connection of the lever L and engages with the outer end of the lever to exert pressure on the plate H. In the construction shown the screw mechanism comprises a vertical stand R having its upper end formed with a rectangular opening R2 through which the outer end of the lever L projects. As shown in Fig. 5 a rectangular plate R3 is pivotally mounted for rotation about a pivot R4 secured at one side of the opening R2. y

The plate is formed with central upper and lower bosses R5 internally screw threaded and through which a threaded bolt S extends.

The bolt is provided with a hand wheel S at the upper end thereof and a block S2 at the lower end thereof. The lower side of the block is cut away to provide a rectangular slot S3 in which a horizontally extending cutout portion L5 of the lever L engages. The plate R3vhas a U-shaped slot R3 at one side thereof arranged to pass around the shaft lof a screw threaded bolt R7 mounted in the opposite side of the opening R2 from the pivot pin R4.

With the above construction, when the lever L is to be operated to press the plate H downwardly, the plate R3 is turned about the pivot pin R4 to open the upper end of the opening R2. The lever is then lowered into said opening, the plate R3 swung to its closed position and secured by the head of the bolt R" contacting with the top surface of the plate portion adjacent the slot R6. The hand wheel S' is then turned to lower the block S2. The downward movement of the shaft S is limited by an adjustable nut S4 secured to the upper part of the shaft.

With the apparatus heretofore described, the expanded metal layers are placed in position on the base plate and the metal surfaces receive a coating of solder as they are submerged in the solder bath. The follower plate G, pressure plate H and washers Q are then placed in position and secured by the bolts K and hand wheels K3 to the4 base plate C. The screw mechanism S is then operated to exert pressure on the plates and interposed metal layers, thereby forcing out air and any gases that may have formed between the layers of sheet material and any excess solder. The compression of the alternate layers of metal and solder unite the same into a unitary laminated sheet structure.

The compression of the superposed layers while submerged in the bath of binder is especially advantageous in that the oxides which form very quickly on the clean surfaces of the layers and with the solder if the layers are exposed to the atmosphere after being coated are eliminated. Furthermore, the excess solder forced out under pressure again becomes a part of the molten mass in the receptacle thus eliminating any waste of the binder material. This method of compressing a plurality of layers while submerged in a; bath of binder is applicable as well to the formation of laminated sheets from a plurality of separate sheets. Advantageously the parts of the apparatus contacting with or submerged in the solder bath are coated with an anti-flux material preferably an aqueous solution of sodium silicate containing about 20% by weight of graphite. The outer surfaces of the metal layers A are also coated with this anti-flux material to prevent those surfaces from adhering with the adjacent plate surfaces.

While still in a heated condition, the combined plate and layer structure .is removed from the solder bath by raising the lever L by a crane hook engaging an opening L6 in the lever after the force screw mechanism is disengaged. The combined plate and sheet structure can be moved vertically and horizontally due to the pivot arrangement of the lever. The laminated structure is then withdrawn from the position between the plates by disconnecting the bolts K and immediately passed between a pair of metallic pressure rolls T and T where a secondary pressing action is performed on the laminated mass. The secondary pressure rolls are preferably' located adjacent the solder bath receptacle so that-the laminated structure may be withdrawn from between the plates by suitable appliances engaging with the overlapping ends of the outer layers A2 and delivered to a table T2 having sections located on both sides of the pressure rolls. Each table section has side anges T3 to prevent the laminated structure from slipping off the table.

In the preferred manner of carrying out my method the greater portion of the total pressing action on the sheet material is performed by the pressure rolls T and T while the initial pressing action is performed by the pressure plate H. The passage of the laminated material through the pressure rolls squeezes out any remaining excess solder and reduces the material to a compact laminated sheet structure of uniform thickness. My method contemplates the simultaneous passage of more than one laminated sheet through the pressure rolls and in the preferred mode of operation several sheets in superposed relation are passed through simultaneously. As shown in Fig. 6 each pressure roll is of solid construction so that most of the heat absorbed from the metal layers passing between the rolls will be retained. A hand wheel T4 is provided for adjusting the position of the upper roll T relative to the lower roll to regulate the final thickness of the laminated sheet structure. It is advantageous to heat the surfaces of the pressure rolls by a torch or other heating device before the initial layer mass is passed between the rolls in order to prevent any chilling of the sheet material.

After the passage of sheet material through the pressure rolls the material is allowed to cool. The creased ends may then be cut off so that the mass consists of Aa plurality of separate sheets united by solder to form laminated sheet material. It may be desirable to eliminate the cutting operation and use the sheets in the condition in which they are discharged from the pressure rolls. It is apparent that other devices might be used to apply pressure to the lever mechanism L and that in some cases that the supplementary pressure rolls may be eliminated.

'Ihe use of a single strip of sheet material creased and folded has advantages over the use of a plurality of separate sheets. The single strip construction facilitates handling of the material, especially when being transferred from the solder bath to the table T2. The construction of the outer layers slightly longer than the intermediate layers provides means for gripping the laminated structure without injuring the main body portion. This construction is also advantageous in that the laminated structure may be fed into the pressure rolls by first inserting the relatively thin projecting layers. The balance of the mass will then pass through the rolls without any' creeping of the superposed layers. The initial pressing action on the layers further prevents creeping of the layers as the adherence of the layers to each other and the integral end connections prevent relative sliding movement of adjacent layers during the passage between the pressure rolls.

In the modified form of the apparatus illustrated in Fig. 7, I have eliminated the base plate mechanism K. In this the metal layers have C and connecting screw form of apparatus after` been subjected to the action of the pressure plate H the layers are withdrawn from the solder bath directly to the table by suitable tools engaging with the extended end portions of I the outer layers A'. The elimination of some of the parts provides a more simple construction, which may be entirely satisfactory where there is no tendency plates and sheet mateof slippage between the connections rial necessitating the use of theend between the plates- While in accordance with the provisions of the statutes, I have illustrated and described the best forms of my invention now known tome, it will be apparent' to those skilled in the art that changes may be made without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

Having nowdescribed my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The method of which `comprises cleaning and fluxing the surfaces to be joined, placing said layers in a superposed relation in a bath of solder wherein the surfaces of said layers are coated with said solder, subjecting the superposed layers to an initial pressing action to form a laminated metallic structure and passing said laminated structure through a second pressing action.

2. The method of making laminated sheet metal which comprises folding a single strip of sheet metal into a plurality of loosely superposed layers, cleaning and fiuxing the surfaces to be joined, coating the surfaces of said material with a layer of solder material and subjecting the superposed layers to pressure whereby the excess solder material is forced out and the adjacent surfaces pressed closely together and caused to adhere to one another.

3. The method of making laminated sheet metal which comprises folding a single strip of sheet metal into superposed layers, cleaning and fluxing the surfaces to be joined, submerging the superposed layer structure in a bath of solder wherein the surfaces of said layers are coated with said solder and subjecting -the superposed layer structure to pressure whereby the contacting surfaces of said layers closely adhere together. 1

4. The method of making laminated sheet metal which comprises folding a single strip of sheet metal into a plurality of superposed layers, cleaning and fluxing the surfaces to be joined, submerging said layers in a bath of heated molten solder, subjecting the superposed layers to an initial pressure action while submerged whereby the adjacent contacting surfaces are united to form a unitary laminated mass, withdrawing the laminated material from the bath and subjecting the laminated material to a second pressing action while the solder is still in a heated condition.

5. The method of making laminated sheet metal which comprises folding an elongated strip of sheet metal into a plurality of superposed sections, cleaning and fluxing the surfaces to be joined, coating said surfaces with a molten solder material, and subjecting the sections while in a superposed position and while said solder material thereon is in a molten condition to suflicient joining layers of sheet metal pressure to cause the adjacent surfaces of adjacent sections to be connected.

6,. The method of making laminated sheet metal which comprises cleaning and fluxing a plurality of metallic sheets, placing the sheets in superposed relation in a bath of metallic solder material, compressing the pack of superposed sheets while in said bath, controlling the thickness of the solder material between adjacent sheets by limiting the degree of compression of the superposed sheets, removing the pack of sheets from said bath, and further reducing the thickness of the pack by a, rolling operation.

7. In the formation of a shim consisting of thin layers of metal connected by interposed solder films, the method which consists in cleaning and fluxing the flat surfaces of thin metal sheets ultimately formingsaid layers, submerging said sheets assembled in loosely superposed relation in a bath of solder, and thereafter subjecting the superposed sheets to a pressure action reducing the solder between each adjacent pair of sheets to a thin connecting film.

8. In the formation of a shim consisting of thin layers of metal connected by interposed solder lms, the method which consists in cleaning and fluxing the flat surfaces-of thin metal sheets ultimately forming said layers submerging said sheets assembled in loosely superposed relation in a bath of solder, thereafter subjecting the superposed sheets to a pressure action reducing the solder between each adjacent pair of sheets to a thin connecting film and cutting the shim from the solder lm connected sheets.

9. In the formation of a. shim consisting of thin layers of metal connected by interposed solder films, the method which consists in cleaning and fluxing the at surfaces of thin metal sheets ultimately forming said layers, submerging said sheets assembled in loosely superposed relation in a bath of solder, and thereafter subjecting the superposed sheets to a pressure action reducing the solder between each pair of sheets to a thin connecting film andregulated to give a predetermined thickness to the superposed sheets and interposed solder films.

NORMAN L. DERBY.

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