US2749760A - Mechanical movement for seam cap riveting and the like - Google Patents

Description

June 12, 1956 a. T. HARCOURT MECHANICAL MOVEMENT FOR SEAM CAP RIVETING AND THE LIKE z sneets-sheet 1 Original Filed May 11, 1948 l1||| I/CHPIIII INVENTOR. GEORGE T A R/PC0057 June 12, 1956 G. T. HARCOURT 2,749,760

MECHANICAL MOVEMENT FOR SEAM CAP RIVETING AND THE LIKE Original Filed May 11, 1948 2 Sheets-Sheet 2 INVENTOR. v 650E615 7. HflRCOURT HTY'OR/YEY MECCAL MOVEMENT FOR SEAM CAP RIVETING AND THE LIKE George T. Harcourt, Detroit, Mich, assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Original application May 11 1948 Serial No. 26,296 Divided and this application November 2, 1950, Serial No. 193,591

4 Claims. (Cl. 74---110) This invention relates to mechanical movements and more particularly to a drive mechanism for portable riveting tools. Such riveting tools are useful in effecting seam cap riveting operations. This application is a division of my original application, Serial No. 26,296, filed May 11, 1948, now Patent 2,539,419, dated January 30, 1951, relating to a hydraulic tool for riveting seam caps on railroad car roofs.

Seam cap riveting is illustrated in United States Patent 2,085,540, issued June 29, 1937, to Walter P. Murphy and which concerns a roof construction for metal freight cars. In effecting such operations, it is essential that the folds of metal which comprise the seam cap assembly, must be securely held and clamped prior to and during the riveting operation if a good rivet setting is to be effected. The seam cap assembly may also include brackets for the car running board which are sometimes riveted with the seam cap and which complicates the riveting operation.

It is an object of the present invention to provide a portable hydraulic riveter which can be conveniently used by an operator to efliciently rivet a seam cap assembly for car roofs of the type shown in the above mentioned patent.

It is another object of the present invention to provide a drive mechanism for a portable hydraulic riveter which includes a rocker member pivoted within the riveter housing which has dependable connections with the respective actuating and actuated members and wherein control of the rocker through its respective connections with the members during the power stroke are independent of the pivot pins which are connected between the rocker and the members.

Other objects of the invention are to provide a mechanical drive mechanism for portable riveters which is of simple, sturdy and rugged construction, compact, inexpensive to manufacture, reliable in operation, extremely serviceable, has low maintenance costs, has a minimum number of parts and efiicient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in connection with the accompanying drawing, in which Fig. 1 is a side elevational view of the portable car roof seam cap riveter embodying the drive mechanism of the present invention, with portions broken away to show the drive mechanism and the interior construction of the riveter.

Fig. 2 is a fragmentary longitudinal sectional view of the slotted rear end of the actuated member which in this case is a ram or rivet set holder and showing in broken lines a part of the rocker arm which actuates the actuated member or holder, the view being taken generally on line 22 of Fig. 5.

Fig. 3 is a transverse sectional view of the riveter taken on line 33 of Fig. 1 and looking in the direction of the arrows thereof.

States Patent Fig. 4 is a fragmentary side elevational view of the riveter showing the pivotal connection of the rocker with the riveter housing, the view being taken looking along line 44 of Fig. 3.

Fig. 5 is a fragmentary longitudinal sectional view of a portion of the riveter and taken through the connection of the rocker with the actuated member of rivet set holder and generally on line 5-5 of Fig. 1.

Referring now particularly to Fig. l, the seam cap assembly upon which this riveter is used comprises a rivet 14 extending horizontally through flanged ends of two adjacent roof sheets 15 and through a seam cap 16 of inverted U-shape which snugly embraces the flanged ends of the roof sheets. The seam cap 16 extends transverse- 1y across the roof of the car at a slight inclination from a horizontal plane and near the center of the roof serves as a support for running board brackets 17. The present riveter is designed to press the sides of the seam cap into tight contact with the roof sheet flanges and then to head the rivet 15 with a squeezing action. The head of the rivet 14 may engage the seam cap directly or may be separated therefrom by a flange of the bracket 17, as shown, depending upon the location of the riveting operation along the seam cap assembly. The present riveter is designed to permit variations in the length of the rivet and in the total thickness of the assembled Work pieces.

A yoke 18 is formed to house and support the various elements of the riveter. The yoke 18 is preferably a steel castingwhich is generally hollow and wherein the walls of the yoke are thin to provide minimum weight and maximum strength in accordance with well known principles of design. The yoke 18 has a bay 19 adapted to provide sufficient clearance for the work assembly and to permit the riveter to be moved both angularly and longitudinally of the running board brackets 17.

In the upper portion of the yoke or housing 18 is an open ended cylinder 21 which is maintained in place by virtue of its press fit with annular projections 22 and 23 extending inwardly from the walls of the yoke 18. A shoulder 24 on the cylinder 21 at its open end abuts the projection 23 to hold the same against forward movement within the yoke or housing 18. Threadedly secured to the open end of the cylinder 21 is a cylinder head 25 in which there is a passageway 26, one end of which opens into the cylinder 21 and the other end of which is threaded for the reception of a hose fitting 27 that projects into an opening 28 in the top wall of the yoke or housing 18. The cylinder head is locked in place by means of two set screws 29, 29, Fig. 3. These set screws pass through the opposite walls of the yoke 18 and engage the cylinder head 25, as shown. The closed end of the cylinder 21 has a threaded opening 31 which receives an elbow fitting 32 to which is secured a hose connection 33, that passes outwardly through an opening 34- in the top wall of the yoke and being generally aligned with the hose fitting 27. Within the cylinder 21 is a slidably operated piston 35 to which is connected a piston rod or actuating member. 37 that passes through a smooth bore 38 in the cylinder head 25.

The end of the piston rod 37 which projects from the cylinder 21 beyond the cylinder head 25 has an enlargement 40 that is bifurcated thereby providing a vertically extending slot 39 which receives the upper end of a rocker 41 enclosed within the yoke 18 and pivotally connected thereto. The enlarged end of the piston rod 37 is indicated generally at 40. On the opposite walls of the slot 39 are respectively vertically extending grooves 42 opposing each other which are adapted to receive the ends of a guide pin 43, Fig. 3, that is retained in the upper end of the rocker 41. It will be noted, as viewed tue of the upper end of the rocker 41 having a curved or I rounded projection 44 that abuts the bottom 39 of slot 39 in the enlargement 40 of the piston rod 37 during the power stroke movement of the piston and of the rocker The rocker 41 has a hub enlargement 41 with a central opening 41" therein. The rocker 41 is fixed to a pivot pin 45, each end of which is maintained in nested needle bearings 46, Figs. 3 and 4, which are surrounded by a bushing 47 that is press fitted in a bore 48 formed in the wall of the yoke 18. At each end of the pin 45 is a closure plate 49 that fits the bore 48 and which is secured by a screw 51 to the end of the pin 45 and which prevents the outward displacement of the several nested needle bearings 46. There is a needle bearing assembly at each end of the pin 45.

The lower end of the rocker 41 has a curved or rounded projection 52 which abuts a rivet set holder or actuated member 53 slidably supported in bushing 54, Fig. 5, which is press fitted in a bore in the rear jaw of the yoke 18. The end of the rivet set holder 53 which engages the rocker 41 is bifurcated to provide slot 55' and has two vertically extending grooves 55 arranged respectively in the opposite walls of the slot 55' to receive the respec tive ends of a pin 56 retained in the lower end of the rocker 41. The pin 56, in acting on the sides of the grooves, serves to transmit return stroke movement from the rocker 41 to the rivet set holder 53 in a manner similar to the action of pin 43 in the grooves 42 of the piston rod enlargement 40. During the power stroke movement of the rocker 41, the rounded projection 52 of the rocker engages the bottom of the slot 55 of the rivet set holder 53, so that there is no strain upon the pin 56. The axis of the pivot pin 45 is closer to the axis of the rivet set holder 53 than to the axis of the power piston 35 whereby the force of the piston is multiplied in the well known manner. A rivet set 57 is tightly fitted in a bore 53 in the rivet set holder, Fig. 5, and may be easily removed when worn or when a different size or style of rivet is to be set by means of shoulder 58, Fig. 1. This shoulder 58 is formed on the outer periphery of the rivet set and against which can be driven a wedge to force the rivet set 57 from the holder 53.

On the forward jaw of the yoke 18 and opposite the rivet set is a pressure pad arrangement 59 having a pressure pad 60 adapted to engage the seam cap assembly and connect it with front toggle links 61, one of which being shown in Fig. 1, that are pivotally connected to rear toggle links 62. Adjustment screws 64, one shown, control the operation of the links. A dolly 69 is tightly fitted within the forward jaw of the yoke 18. The pressure pad 60 is thus arranged for reciprocal motion to and from the rear yoke jaw in a fixed plane. The dolly 69 receives the rivet 14 and the rivet is upset thereby. The pressure pad arrangement is so arranged as to provide maximum clamping pressure of the work prior to and at the commencement of the riveting operations followed by an automatic decreasing in pressure so that at the time the rivet upsetting begins, the greater part of the power of the work cylinder, which is applied to overcome the resistance of the pressure pad, is applied to upsetting the rivet.

At the rear of the yoke 18 is a plate 80 having a hollow handle 81. A trigger 82 of a switch assembly lying within the handle 81 to which access is had by removal of a closure plate 83. An electric cable 84 extends from .4 the handle and may extend to a valve or the like which controls the supply of fluid to the cylinder 21.

The riveter is suspended from a bail 93 that is connected to the front end of the yoke 18 by a trunnion arrangement 94. This arrangement has an arm 101 that may engage a stop 102 to limit the rotation of the trunnion arrangement 94.

In operation, the riveter is positioned so that the rivet set 57 contacts the head of the rivet 14 which is located in a hole in the work pieces, the other end of the rivet extending through the work piece in the direction of the pressure pad 59 or dolly 69. The trigger 82 is pressed initiating operation of the power plant, not shown, and resulting in the pressurized oil being delivered to the cylinder through the hose connection 33. The piston 35 is forced rearwardly in the cylinder 21 causing the rocker 41 to be rotated in a clockwise direction about the pivot pin 45 thereby tending to drive the rivet set holder 53 forward and in the direction of the forward jaw of the yoke 18. However, since the holder 53 abuts the work piece by way of rivet set 57, the work piece being stationary, prevents forward movement of the rivet set holder 53, with the result that the motion is transferred to the yoke 18, which thereupon moves in a rearward direction in unison with the pressure pad 60 causing the pad to engage the work piece or the seam cap assembly in the manner as illustrated. Continued movement of the yoke 18 causes the pressure pad 60 to tightly squeeze the work piece until the dolly 69 moves rearward relative to the pressure pad and contacts the rivet. The operator then observes through transverse slot 104 in the pressure pad 60 Whether or not the dolly 69 and the rivet 14 are properly aligned, releasing the trigger if necessary to prevent this operation. If the trigger is kept pressed, the oil pressure and mechanical pressure is built up rapidly and the rivet heading operation begins, but the effect of the pressure pad 60 is gradually diminished as the mechanical advantage of the toggle links 61 and 62 increases.

When the rivet heading is completed in the dolly and the piston 35 has travelled its maximum distance, the pressure in the high pressure delivery hose builds up to such a value as to automatically reverse the operating cycle of the power plant, whereupon the oil in the high pressure hose is released and low pressure oil is delivered to the cylinder 21 by way of the hose connected to the fitting 27, thereby forcing the piston 35 to return to its first position in the cylinder. In so doing, the rocker 41 is moved in a counterclockwise direction thus causing the return of the rivet set holder 53 and the pressure pad arrangement 59 to their initial position so that the riveter can be removed for positioning for subsequent riveting operations.

During both the power and return strokes, the movement of the rocker is effected. With the curved or rounded projections 44 and 52 on the arms of the rocker which engage with the bottoms of the slots in which they extend, the use of the pins 43 and 56 is eliminated during the power stroke. The pins 43 and 56 are used only upon the return stroke of the piston and the rocker is rotated in a counterclockwise direction. The movement of the rocker at this time is when there is no strain upon the members. The pins 43 and 56 being of less diametrical width than the width of the slots to permit the easy engagement of the rounded projections 44 and 52 with the bottom of the slots.

It should now be apparent that there has been provided a mechanical movement and drive mechanism for riveters wherein there is little opportunity for breakage of parts and that the life of the connecting pin between the ends of the rocker is increased inasmuch as the power stroke pressure is not placed upon the pins and wherein adequate vertical displacement of the pins and the slots or grooves is permitted to prevent binding of any of the parts.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In a mechanical movement, an actuating member having a bifurcated portion thereby forming a slot, a supporting member, a rocker pivoted upon the supporting member, said rocker having an arm with a curved projection adapted to cooperate with the bottom of the slot of the actuating member, said rocker having a second arm with a curved projection, an actuated member having a bifurcated portion with a slot therein, said curved projection of the rocker second arm being engageable with the bottom of the slot of the actuated member, whereby the pressure being applied by the actuating member and to the actuated member is applied through the curved projections, and the bifurcated portions of the actuating and actuated members having respectively opposing vertically extending grooves, a pin in each arm of the rocker and extending into the grooves of the bifurcated portion of the associated member, said pins being of less diameter than the width of the vertically extending grooves.

2. In combination, a supporting member, slidable actuating and actuated members mounted in the supporting member for adjustment, each of said slidable members having an end slot providing bifurcated portions, a rocker member pivoted upon the supporting member and having its opposite ends lying respectively in the respective slots of said members and engaging respectively with the bottoms thereupon whereby upon the actuating member being operated power is transmitted to and from the rocker member through the edge thereof, and the bifurcated portions of at least one of said slidable members having vertically extending grooves on their inner faces thereof and opposing one another, a pin lying in said grooves and extending through the rocker whereby to eflect the return movement of the rocker.

3. In combination, a supporting member, slidable actuating and actuated members mounted in the supporting member for adjustment, each of said slidable members having an end slot providing bifurcated portions, a rocker member pivoted upon the supporting member and having its opposite ends lying respectively in the respective slots of said members and engaging respectively with the bottoms thereupon whereby upon the actuating member being operated power is transmitted to and from the rocker member through the edge thereof, and the edge of said rocker member having rounded portions for engagement with the respective bottoms of the slots of the slidable members, and the sides of the bifurcated portions of each of the members having respectively vertically extending grooves opposing one another, a pin connected to each end of the rocker and extended through the rocker end and into the grooves of the member.

4. In a mechanical movement, a supporting means, an actuating member arranged for reciprocable movement Within the supporting means and having an end portion with an open ended slot, a rocker arranged for pivotal movement Within the supporting means, said rocker having a first arm with a curved projection adapted to engage the bottom of the slot of the actuating member, an actuated member arranged for reciprocable movement within the supporting means and having an end portion with an open ended slot, said rocker having a second arm with a curved projection adapted to engage the bottom of the slot of the actuated member, and means connecting the actuating and actuated members with the respective arms of the rocker so that said curved projections are maintained in close proximity to the bottom of the respective slots.

References (Zited in the file of this patent UNITED STATES PATENTS 1,605,402 Hay Nov. 2, 1926 1,886,241 Chapman Nov. 1, 1932 2,053,720 Huck Sept. 8, 1936 2,083,334 Harcourt June 1, 1937 2,276,301 Gregory Mar. 17, 1942 2,365,154 Storz Dec. 19, 1944 2,387,449 Kaman Oct. 23, 1945 2,399,907 Blair May 7, 1946 2,439,284 Buckwalter Apr. 6, 1948 FOREIGN PATENTS 829,888 France Apr. 25, 1938

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