US2488902A

US2488902A - Automatically timed rivet setting machine

Info

Publication number: US2488902A
Application number: US722903A
Authority: US
Inventors: Thomas J Doyle
Original assignee: TUBULAR RIVET AND STUD Co
Current assignee: TUBULAR RIVET AND STUD Co
Priority date: 1947-01-18
Filing date: 1947-01-18
Publication date: 1949-11-22
Anticipated expiration: 1966-11-22

Description

Nov. 22, 1949 T. J. DOYLE 2,483,902

v AUTOMATICALLY TIMED RIVET SETTING MACHINE Filed Jan. 18, 1947 2 Sheets-Sheet 1 a: U U

j INVENTOR. l

Aria/M51 Nov. 22, 1949 "r. J. DOYLE AUTOMATICALLY TIMED RIVET SETTING MACHINE 2 Sheets-Sheet 2 Filed Jan.

,q roziwar Patented Nov. 22, 1949 AUTOMATICALLY TIMED RIVET SETTING MACHINE illioinas J. Doyle, Milton, Mass, assignor to Tubular Rivet and Stud Company, Quincy, Mass., a corporation of Massachusetts Application January 18, 1947, Serial N 0. 722,903

3 Claims.

This invention relates to an automatically timed rivet setting machine.

The invention has for an object to provide a novel rivet setting machine capable of performing the rivet setting operation in a superior and economical manner.

A further and more specific object of the invention is to provide a novel rivet setting machine which is capable of performing the rivet setting operation independently of the operator to the end that the rivet setting operation may be performed under uniform conditions during successive cycles in the operation of the machine.

A still further object of the invention is to provide a novel rivet setting machine of the pneumatically operated type which is capable of uniformly setting successive rivets irrespective of reasonable variations in thickness of the parts being riveted and irrespective of the judgment and skill of the operator.

With these general objectsin View and such others as may hereinafter appear, the invention consists in the rivet setting machine and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification.

In the drawings illustrating the preferred embodiment of the invention, Fig. l is a side elevation of a rivet setting machine embodying the present invention; Fig. 2 is a detail view in front elevation of a solenoid operated air valve forming a part of the control mechanism to be hereinafter referred to; Fig. 3 is a detail view, partly in cross section of the rivet setting elements shown in position preparatory to setting a rivet; Fig. 4 is a similar view with the parts shown in their rivet setting position; and Fig. 5 is a diagrammatic View illustrating the control mechanism embodying the present invention.

In general, the present invention contemplates a novel rivet setting machine, and particularly a machine for setting hollow rivets, which may be used with advantage in rivetting the parts of the work which are fragile in nature, such as pieces constructed in whole or in part of ceramics, plastics and the like. In its broader aspects the invention contemplates a rivet setting machine capable of operation to perform the rivet setting operation independently of the operator, to the end that successive rivetting operations may be performed under uniform conditions as to time, thus insuring satisfactory operation without loss of production. The rivet setting machine may and preferably will comprise a machine of the pneumatically operated type, and in the preferred embodiment of the invention such a machine is preferably provided with control mechanism for controlling the operation of the machine during each cycle so that once the machine has been started upon a cycle of operation the cycle is automatically completed within a predetermined time and independently of the operator. Provision is also preferably made for adjustably varying the length of time afforded the rivet setting operation. 7

Referring now to the drawings, the invention has been illustrated as embodied in a rivet setting machine for setting hollow rivets and which machine is of the pneumatically operated type wherein a driver It} is arranged to be pneumatically and vertically reciprocated, and in one position of operation, to cooperate with an anvil E2 to perform the rivet setting operation. The parts of the work to be riveted are manually held in operative relation, as illustrated in Figs. 3 and 4. As herein shown, the anvil l 2 may and preferably will be of the spring pin type which includes a normally extended pin M over which the parts to be riveted are assembled, the pin M extending through preformed openings in the parts, as shown in Figs. 3 and 4. During the rivet setting operation the rivet It is urged into engagement with the pin it by descent of the driver to depress the pin until the latter engages a stop whereupon the pin comes to rest and, as the driver continues, the hollow end of the rivet is caused to flow outwardly by the cooperation of the aligned annular concave surfaces of the end of the pin it and the end of the body portion it of the anvil. A typical piece of work to be riveted is herein illustrated as an electrical connector having a dielectric and relatively fragile base 20, a metal washer 22 on the underside thereof, and a metal terminal 2 5 on the upper side. The anvil I2 is supported in a standard 25 mounted in a bracket 2] attached to the machine frame.

The rivet setting machine is further provided with means for feeding rivets into operative rivetting position, said means being herein shown as comprising the usual rotary supply hopper 26, which is arranged to deposit the rivets into a guide chute 28 from which they are successively released by an escapement mechanism 36 operated upon reciprocation of the driver It} to deposit a rivet during each cycle of operation into a separable holder 32 arranged to support the rivet in alignment with the driver It! and the work. As herein shown, the rivet setting driver in is mounted in a vertical guide 34 formed in a supporting bracket 36 attached to the machine column 38 and is arranged to be reciprocated through connections from the piston 64 (Fig. of a pneumatic cylinder 45. The cylinder 38 is pivotally supported at its lower end in a bracket 42 (Fig. 1) attached to the column 38 and is provided with a piston rod 44 connected to one arm 56 of a tWmar-med lever pivotally mounted at :8 in the supporting bracket 36. The second arm 58 of the two-armed lever is connected by a link 52 to the upper end of the driver ill. Provision is also made for efiecting intermittent movement of the rotary element in the supply hopper 26 through connections from the rocking arm 46 including a link 54 connected to a pawl and ratchet mechanism indicated generally at 56 and forming a part of the usual rivet feeding mechanism for releasing successive rivets into the inclined chute 28.

As illustrated in Figs. 1 and 2 the pneumatic cylinder 40 is of the double-acting type and the .operation of the piston 64 thereof is arranged to be controlled by a valve head 69 which is mounted on a bracket 62 attached to the machine column. The valve head 60 is arranged to communicate with the lower end of the cylinder by a flexible connection 63 to effect movement of the piston 64 in one direction, and a second flexible connection 66 communicating with the upper end of the cylinder is arranged to effect movement of the piston in the opposite direction, as controlled by the valve head 60. The valve head it may be connected to any usual source of compressed air by a flexible tube 58 and may be provided with conventional apparatus for controlling the air including an air filter lll, pressure regulator 12 and pressure indicating gauge H! as illustrated in Figs. 1 and 5. The pneumatic cylinder 40 may and preferably will be of the type provided with cushioning means for cushioning the piston as it approaches the end of its stroke so as to effect a gradual compression and clinching of the rivet so as to prevent breakage of relatively fragile parts to be secured together by the rivet. As herein shown, the cylinder may be provided with cushion adjusting valves 18 for controlling the cushioning effect.

From the description thus far it will be observed that through the operation of the valve head 6!] the piston 64 of the cylinder 49 is actuated to effect descent of the driver It into rivet setting engagement with the Work, the descent of the driver being terminated by the resistance of the set rivet and the work, and after a predetermined length of time the driver is elevated to complete the cycle of operation. In accordance with the present invention, provision is made for automatically controlling the valve head 6!! to efiect elevation of the driver 40 after a predetermined length of time, after the driver it! has started its downstroke, suflicient to assure completion of an eflicient riveting operation without dependence on the skill and judgment of the operator.

As herein illustrated, the control mechanism comprises an electrical circuit which includes a solenoid 80 for operating the valve head 59 and an adjustable time delay relay indicated generally at 82 and arranged to be set to effect opening of the circuit to the solenoid after a predetermined length of time has elapsed. As shown in Figs. 2 and 5, the solenoid plunger 84 is connected by a link 85 to one end of a lever 86 pivotally mounted at 88 above the valve hea the lever 88 also being provided with valve stems 98, 92 on opposite sides of the pivot 38 so that in operation when the lever 3-3 is rocked the valves may be shifted to reverse the operation of the piston 64 of the pneumatic cylinder 36. The valve lever 85 is normally urged into its upwardly rocked position, as illustrated in Fig. 5, by a spring and rod connection 9:3, and is arranged to be rocked downwardly when the solenoid is energized.

As illustrated in Fig. 5, the circuit to the valve actuating solenoid includes a main lead 855 from the main line switch 98, a cross lead tilt connected thereto, a lead H32 connected medially oi its length to the lead 10!) and connected at one end thereof to a contact on the relay unit 82 and having its -.other end connected to one side of a manually operated, normally open, momentary contact switch m4, and a lead ")6 from the other side of the momentary contact switch Hill to the solenoid 3t. n lead 168 from the solenoid 82: is connected to a normally closed relay switch iii-{I in the time delay unit 82, and a lead H2 from the relay switch H5 is connected with the other side of the main line through a contact of the relay unit 82. As above described, the spring connection 94 is arranged to maintain the valve lever 85 in its upwardly rocked position, this position corresponding to an elevated position of the driver iii. Thus, in the operation of the control meachnism, when the momentary contact switch Hi l is closed by the operator and immediately released by him, the solenoid 82 is energized to cause shifting of the valve 58 and descent of the driver i e into rivet setting engagement with the work. Provision is made for automatically controlling the return movement of the driver in so that the rivet setting operation may be completed in a predetermined time after the driver is thus started downwardly, and accordingly, a holding circuit is provided for continuing the circuit to the solenoid 88 after the momentary contact switch Hi l is automaticaly opened and, as herein shown, a micro-switch H4 which is maintained in its open position by engagement of the lever 88 in its upwardly rocked position is permitted to close when the solenoid '83) is energized to rock the lever 86 downwardly to maintain the circuit to the solenoid through lead H6, switch H4, and lead H8 thus bypassing or shunting the open momentary contact switch I04.

In the illustrated embodiment of the invention provision is further made for closing a circuit iZG to the timing mechanism of the time control unit 82 upon downward rocking of the valve lever 85 and, as herein shown, a second micro-switch I22 is arranged to be closed by engagement of the lever 85 therewith when the solenoid 30 is energize and has moved lever 86 down far enough to close switch I22. The circuit (28 to the timing mechanism includes the leads 9%, Hi5, H32, lead I26 to the micro-switch H2 and a lead from the micro-switch to a terminal 128 of the timing mechanism, the circuit being completed through the timing mechanism and through a lead 138 to the main line lead H2. In the operation of the timing mechanism, as is well-known in the art, after a predetermined length of time has elapsed after the closing of the momentary switch Hi4, the holding circuit to the solenoid Bil is automatically opened at the relay switch HD to deenergize the solenoid 89 and to permit the spring connection 94 to again rock the lever 86 upwardly thus eifecting shifting of the valve head 60 and elevation of the driver Ill by the air cylinder 40. As herein shown, the timing unit 82 may and preferably will be of the known type provided with a time setting adjustment knob i32 which may be set at the time desired, as indicated by the graduations of the dial I34. Such conventional timing devices usually include a condenser which is normally charged by line current to a voltage potential determined by the setting of the knob I32. That is to say, the condenser is charged to this voltage while the microswitch I22 is open. When the momentary manual switch E64 is closed, the solenoid St is operated and the actuating member 86 is moved downwardly to close microswitch 822. This completes a circuit to two of the terminals of the timing device 82 through the leads I26 and I24, I82, for enabling the discharge of the condenser through a resistor. After a definite time interval, during which the condenser is discharging, which time interval is determined by the charge on the condenser as set by the adjustment of the knob I32, the relay switch Ht opens. This deenergizes the solenoid 83 to allow microswitch I22 to open, and upon opening of the microswitch :22 the condenser is again charged to the voltage set by the knob I32. The timing device 82 is also such that opening of the switch !22 causes closing of the relay switch I IE! to automatically re-set the timing device for the next cycle of operation.

From the above description it will be seen that the present pneumatically operated rivet setting machine is provided with control mechanism which may be adjusted to definitely determine the time of a cycle of operation of the vertically reciprocal rivet setting element independently of operator control so as to prevent elevation of the rivet setting element prior to completion of the rivet setting operation and thus assuring complete clinching of the rivet with the work and also to prevent maintenance of the rivet setting element in rivet setting engagement with the work longer than necessary thus obtaining maximum production from the machine. It will also be observed that the present control mechanism is of particular advantage in those instances where successive parts to be riveted vary slightly in thickness, the control mechanism enabling the 1. A rivet setting machine, comprising: a

driver; an anvil; means for eiTecting relative movement of the driver and anvil to perform a rivet setting operation; means for controlling the operation of said first-mentioned means including an actuating member; means including an element operable by the operator for effecting initial actuation of said actuating member from one position to another to start a riveting cycle; timing means automatically operable after the machine has been started upon a riveting and without cycle for controlling the time interval of the setting portion of said riveting cycle; means for eiTecting' a return of said actuating member to said one position at the end of said time interval, said timing means being constructed and arrangedso that the started riveting cycle cannot be interrupted by the operator; and means for automatically restoring the machine and timing means to starting position after the completion of the riveting cycle.

2. A rivet setting machine, comprising: a driver; an anvil; fluid operated means for effecting relative movement of the driver and anvil to perform a rivet setting operation; means for controlling the operation of said fluid operated means including a valve controlling the supply and exhaust of operating fluid to and from said fluid operated means; a valve actuating member; a circuit having a normally open manually operable switch and a solenoid connected therein for efiecting initial actuation of said actuating member to move said valve from one position to another to admit operating fluid into said fluid pressure operated means to start a riveting cycle upon closing of said manually operable switch; a timing relay connected in said circuit in series with said solenoid and having a normally closed switch adapted to automatically open upon the expiration of a predetermined time interval after the closing of said manually operable switch for controlling the time interval of the setting portion of said riveting cycle and for interrupting the circuit to said solenoid to deenergize said solenoid and permit said actuating member to return said valve to said one position to exhaust operating fluid from said fluid operating means at the end of said time interval, said timing relay being constructed and arranged so that the switch of said timing relay cannot be opened by the operator during the started riveting cycle to interrupt the cycle; and means for automatically restoring the machine and timing relay to starting position after the completion of the riveting cycle.

3. A rivet setting machine, comprising: a driver; an anvil; fluid operated means for effecting relative movement of the driver and anvil to perform a rivet setting operation; means for controlling the operation of said fluid operated means including a valve controlling the supply and exhaust of operating fluid to and from said fluid operated means; a valve actuating member; a circuit having a normally open manually operable switch and a solenoid connected therein for efiecting initial actuation of said actuating member to move said valve from one position to another to admit operating fluid into said fluid pressure operated means to start a riveting cycle upon closing of said manually operable switch; a holding circuit for maintaining said solenoid energized after said manually operable switch automatically opens following manual closing thereof; a timing relay connected in said circuit in series with said solenoid and having a normally closed switch for completing said holding circuit, said relay switch being adapted to automatically open upon the expiration of a predetermined time interval after the closing of said manually operable switch and for controlling the time interval of the setting portion of said riveting cycle and for interrupting the circuit to said solenoid to deenergize said sol noid and permit said actuating member to return said valve to said one position to exhaust operating fluid from said fluid operated means at the end of said 8 time interval, said timing relay being constructed UNITED STATES PATENTS and arranged so that the switch of said timing Number Name Date relay cannot be opened by the operator during 1 383 533 Crook July 5 1921 the started riveting cycle to interrupt the cycle; 1672384 Jensen "June 1928 and means for automatically restoring the ma- 5 oskow 0 chine and timing relay to starting position after the completion of the riveting cycle.

THOMAS J. DOYLE.

REFERENCES CITED :The renewing references are or record in the file bf this patent: