US1958869A - Riveting machine - Google Patents

Description

May 15, 1934. w. STEVER 1,958,869

RIVETING MACHINE- FiledJuly 10-. 1950 ZSheets-Sheet 2' INVENTOR. 'lyillz nv/Szeder;

- ATTORNEY.

Patented May 15, 1934 RIVETING MACHINE William Stever, Philadelphia, Pa., assignor to Edward G. Budd Manufacturing Company, Philadelphia, Pa., a corporation of Pennsylvania Application July 10, 1930, Serial No. 466,975

8 Claims.

In many classes of work in which rivets are used for securing means, it is highly desirable that uniformity of riveting be had. This desirability arises not only by reason of appearance, but, also, and perhaps more importantly, by reason of economy. Uniformly headed rivets present a more neat appearance particularly in multiple numbers of rivets which lie side by side. Uniformly headed rivets are likewise desired where a certain unilil formity is standard for sheets of a given gauge and rivets of a given size; likewise, in fortifying the strength of the rivets as a securing means and preventing the impairment of that strength by careless workmen giving the rivets too much or too little head. Uniform riveting, makes it possible to prevent operatives from wasting the power used, particularly in compressed air riveting machines. Operatives more commonly than not leave the power on the machine much longer than necessary to produce heads on their rivets suificient to develop the maximum strength of the shank. This not only impairs the strength of the rivets, as aforesaid, but is an entire waste of the power itself. I

The aims of this invention have to do with a method and a machine for carrying out the method which will preclude the embodiment of neatness and strength of equipment, and which at the same time will positively limit the application of power to that amount necessary to produce that snugness of head upon the work which will develop the full strength of the shank of the rivet and the most perfect rivet joint.

The method consists in limiting the overall pressed air riveters, by setting a standard of rivet length in connection with the rivet operation, measuring the length of the rivet with each impact stroke and on that stroke which measures the length equal to the standard cutting oil the impact. Preferably the measuring is automatic and preferably the termination of the impact stroke through measuring the length on the standard length is also automatic. Preferably also the manual control is superseded by the automatic control as soon as the riveting operation is initiated.

" The machine comprises a die engaging the opposite ends of the rivet, a continuously operated impact motor operating the dies to head the rivet and means controlling the operation of the motor subject to the degree of approach of the dies. Specifically there is used a compressed air motor provided with a manual control valve for initiat- 55 ing its operation, and an electro-magnetic valve length of rivets headed under impact as by com' for terminating the operation. The circuit of the electro-magnetically operated valve is subjected to the degree of approach of the dies towards each other by means of a switch operated at a determinate degree of approach, and an interlock is provided between the manual control valve and. the electro-magnetic control valve, after the manual control valve has been operated to supersede its control by the electro-magnetic control.

Of the drawings:

Fig. 1 is a general side elevation of the machine.

Fig. 2 is a general perspective of the riveting dies, the impact motor and the control system therefor.

Fig. 3 is a detail of the interlocking device.

The riveting machine per se is a standard type comprising a yoke 10, horizontally disposed, and carrying lower and upper dies 11 and 12, for operating on opposite ends of the rivet. This yoke is mounted on a pedestal 13, from a base 14', on the floor. The lower die 11 is normally med, but both exchangeable and adjustable. The upper die 12 is impact operated through the compressed air motor 15 adjustably carried on the upper arm of the yoke 10. This adjustment is in the form of a. bolted-on extension 16 on the upper arm of the yoke and by changing and shifting of which the arm may be variably spaced vertically from the lower arm of the yoke and also lengthened or shortened as well.

This motor is of the usual type, well known to the art, which when the air is turned on moves the die 12, to the work and subjects it as so applied to the work to a rapid fire of impacts by the hammer which it contains. It is not necessary because of the well known character of these motors, to go into the mechanism and explain the means by which the die 12 is first moved to the work and thereupon subjected to the successions of -impacts. Suilice it to say that it is controlled by a manually operated valve 17, in the compressed air supply line 18 leading to the motor 15 and that this valve contains admission and exhaust ports so arranged that when the valve opens, it subjects motor 15 to line pressure, moving die 12 to the work and when 100 it closes, its exhaust ports open the air chambers of motor 15 to atmosphere and permits it to retract die 12 from the work. In the form shown the valve is of a type rotatable on the axis of the supply conduit 18.

Valve 17 is controlled in the usual manner by a foot pedal 19, connecting through lever 20 pivoting on a. base 14, with a shank 21, in turn connected with a crank, 22 of the shaft"2 3' carried by the upperarm of the yoke, 10. When foot pedal 19 110 is depressed, shaft 23 is oscillated and this oscillation is transmitted by crank arm 24, which.it carriesthrough shank 23 to the valve lever 26 of valve 1'7. This valve is again opposed by spring 27 on the shank 21 which reacts against the fixed stop 28 on the back of the yoke 10. When the foot is removed from the pedal 19, the reaction of the spring 27 restores the parts to normal position in which valve 1'? is closed. against fiuid pressure supply.

Also in conduit 18, is a second valve 29. This valve is electro-magnetically operated through a solenoid 30. The valve itself functions in a mam ner essentially similar to valve 17, although it is somewhat different in form. It is controlled over circuit 31 from the mains 32. In circuit 31 is double pole switch 33 not only controlling the mains 32, but also the switch points 34 in series therewith which are normally open. Switch points 34 are contained in a box 35 on the side of the yoke 10. Ihey are adapted to be closed together through the intervention of a pivoted contact lever 35. This contact lever is I subject to the action of a pair of relatively adjustable cams, 36 and 3'7 carried on a vertically disposed spindle 38 borne in bearings 39 from the yoke 10. The spindle is subjected to vertical reciprocation in its bearings by means of an arm 40, rigidly but adjustably carried by the upper die holder 41 of the motor 15, and which is projected rearwardly to engage over an arm projecting from the spindle 38. This arm 40 and spindle 38 move downwardly against the reacting pressure of the spring 41'. In the downward movement the spindle tends to close the points 34 in the circuit 31 and thereby closing the circuit of solenoid 30. The upper end of the spindle 38 is connected to a laterally projecting resilient lever 42 in the plane of the bell crank arm, 24 upon shaft 23. Lever 24 is provided with a cam shaped tooth 43 on its upper side which normally is engaged on its upper surface by the under side of the resilient lever 42. This lever 42 may, by the way, supplant the necessity for a reacting spring 41' for retracting the spindle 48 upwardly. When pedal 19 is pressed and lever 24 is carried downwardly to open valve 17, to start motor 15, the tooth or detent 43 is moved outwardly as respects the end of the resilient arm 42 carried by spindle 48. Thereupon, when die holder 41 moves downward to carry die 12 into contact with the work, the end of the resilientarm 42 may pass downwardly behind the rear edge 44 of the detent-43.

This machine cannot but carry out the method of my invention, and thereby attains its objects and aims. When the machine is first set for the particular work to be done, the dies, 11 and 12, best suited tothat work are selected. Thereupon arm 40- is adjusted on the die holder 41 and'cams', 36 and 3'7, are adjusted on the spindle 38 with respect to the cam ,follower, 45 on lever 35, so that switch points 34 are closed on the down stroke of the motor 15, only when the dies 11 and 12 are brought towardseach other in a determinate distance equal to the standard overall length of the rivet desired for perfect heading, snug fitting and maximum security. This distance is known to the operative, or not being known, can be determined by trial and error. Once set, it constitutes the standard length for all rivets of the same size in the same gauge of material. Thereupon, the work being placed in the machine the operative presses pedal 19. This causes valve 1'7 to apply air to motor 15 which promptly moves die 12 down upon the work and commences the impacts which head the rivet. This opening of valve 1'7 carries detent 43 downwardly'exposing its rear edge 44 to the end of the arm 42. The downward movement of die holder 41 carries the spindle 38 downwardly with arm 42 and places the resilient arm 42 behind to the rear edge 44 of the detent 43. This constitutes a mechanical interlock between the manual control valve 17 and the auto-.

matic control valve 30, for valve 1'7 may not now be opened by the release of foot pedal 19. There is no reaction of spring 2'7, until or unless the electro-magnetically controlled valve 29 has been cut out to relieve motor 15 of fluid pressure. The impacts continue until the downward move-= ment of the die holder 41 incident to the progressive shortening of the rivet under impact has resulted in the close of circuit 31 at points 34. On that impact'when the length of the rivet has been reduced to the standard length by the adjustment of the parts as above outlined, the contacts 34 are closed and circuit 31 is completed (double pole switch 33 having been closed to start the machine) and valve 29 releases motor 15 of pressure quite independentlyof valve 1']. Immediately upon the release of pressure, die holder 41 and die 12 are raised from the work by the reacting springs of the motor (not shown), spindle 38 is restored to normal position and points'34 are again opened. This same action removes resilient lever 42 from the rear edge 44 of detent 43, and manual control may again be initiated for the succeeding riveting operation.

Obviously the method and machine are both susceptible to a modification, particularly as the general organization of the control is subject to modification and embodiment in diflerent forms. It is well known that hydraulic, compressed air, mechanical, electrical, etc., systems of power may be utilized interchangeably for the effecting power control operations, and this is primarily a power control operation.

Accordingly the appended claims should be given a very broad interpretation entirely independent of the circumstantial terminology herein used in an attempt to express the generic spirit of the invention.

What I claim is:

1. A riveting machine comprising dies engaging opposite ends of the rivets and a continuously operating fluid actuated impact motor for -upon a pre-determined degree of approach of the dies.

3. A riveting machine comprising dies engaging opposite ends of the rivets, a continuously operating'fluid actuated impact motor for relatively approaching the dies to forge the ends of the rivet, an electro-magnetically operated motor control valve, a circuit controlling said valve, and means operative upon a 'pre-determined approach of the dies to establish said circuit.

, 4. A riveting machine comprising dies adapted to engage opposite ends of a rivet, a continuously operating fluid actuated impact motor for relatively approaching the dies to forge the rivet, and dual control means for the motor, one adapted for manual operation to initiate the action of the motor and the other operated automatically through the degree of approach of the dies towards each other to lock out the manual control, stop the motor, and finally reset the manual control.

5. A riveting machine comprising dies adapted to engage opposite ends of a rivet, a continuously operating impact motor for relatively approaching the dies to forge the rivet, and a dual control means for the motor, one adapted for manual operation and the other operated automatically through the degree of approach of the dies towards each other, together with an interlocking means between the manual and the automatic control which prevents the manual control after the initiation of the riveting operation until a riveting operation is completed.

6. A riveting machine comprising. dies adapted to engage opposite ends of a rivet, a continuously operating impact motor relatively approaching the dies to forge the rivet, and a dual control means for the motor, one adapted for manual operation and the other operated automatically through the degree of approach 01" the dies towards each other, and an interlock between the manual and automatic control means comprising a detent cooperating with the automatic control to preclude the use of the manual control means after the initiation of the riveting operation but restoring its use immediately upon the completion of a riveting operation.

'7. A riveting machine comprising dies engaging opposite ends of the rivet, a continuously operating impact motor to head the rivet, a manual control valve to initiate the operation of the motor, an electro-magnetically actuated valve in series with the manual control valve and a control circuit therefor rendered operative to actuate the valve upon a pre-determined approach of the dies towards each other, together with aninterlock between the valves preventing operation of the manual control valve after the initiation of a riveting operation and until its completion. v

8. A riveting machine comprising dies engaging opposite ends of the rivets, means for causing' said dies to relatively approach each other and deliver a succession of impacts to the rivet in their approach, and means automatically ac- WILLIAM STEVER.

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