US3700139A

US3700139A - Rivet slug injector

Info

Publication number: US3700139A
Application number: US50825A
Authority: US
Inventors: Earl K Kelly
Original assignee: McDonnell Douglas Corp
Current assignee: McDonnell Douglas Corp
Priority date: 1970-06-29
Filing date: 1970-06-29
Publication date: 1972-10-24
Anticipated expiration: 1989-10-24

Abstract

An intermittent acting mechanism receiving rivet slugs from the delivery tube of a rivet dispenser for injecting each slug into a spring loaded finger mechanism which, in turn, inserts the slug into a previously drilled hole for a rivet upsetting action by an automatic riveting machine. A photoelectric cell verifys insertion of the rivet slug into the finger mechanism and signals for the next step in the drilling operation. An adapter unit permits rapid and accurate conversion for slugs of different diameters and lengths without extensive alignment and readjustment.

Description

[451 Oct. 24, 1972 11/1963 Klancnik................221/271X 11/1970 Spisak.......................221/233 FOREIGN PATENTS OR APPLICATIONS 11/1963 Germany...................22l/241 yer and ABSTRACT An intermittent acting mechanism receiving rivet slugs from the delivery tube of a rivet dispenser for injecting finger mechanism g into a previously drilled on by an automatic rivet- Primary Examiner-Smauel F. Coleman Attorney-Walter J. Jason, Donald L. R0 Robert 0. Richardson each slug into a spring loaded which, in turn, inserts the slu hole for a rivet upsetting acti ing machine. A photoelectric cell verifys insertion of Inventor: Earl K. Kelly, Lynwood, Calif. Assignee: McDonnell Douglas Corporation Filed: June 29, 1970 Appl. No.: 50,825

Field of Search 221/239, 255

References Cited UNITED STATES PATENTS United States Patent Kelly 1541 RIVET SLUG INJECTOR [721 X the rivet slug into the finger mechanism and signals for the next step in the drilling operation. An adapter unit X permits rapid and accurate conversion for slugs of difx ferent diameters and lengths without extensive align- Erickson................22l/241 X ment and readjustmem' Mead ....22l/239 X f Taylor ...................221/241 X 2 Claims, '5 Drawing Figures RIVET SLUG INJECTOR BACKGROUND OF PRESENT INVENTION For automatic riveting machines, a quantity of rivet slugs are placed in a rivet dispenser which, in turn, channels the slugs into a tube in end-to-end relationship. Each slug is then moved by a rivet slug injector from this dispenser tube into a finger mechanism which, in turn, inserts the slug into a previously drilled hole and the riveting action takes place. Since rivets are of various sizes and lengths, adjustments must be made when converting from one size to another.

Much non-productive time occurs when rivet slug injectors of present design are used and it is desired to change rivet slug diameters. Trail and error adjustments are presently required by such a conversion and time losses are attributable to the malfunction of the present injectors. In the conversion of a riveting machine to drive rivet slugs of another size, the type of injector now in use must be removed and replaced with a similar unit of appropriate capacity. The photoelectric cell obstructs access to the injector mechanism and must be removed, replaced and realigned. Alignment of the cell for proper operation is critical and the conversion also entails bending the rivet slug delivery tube to achieve proper alignment with the alternate injector. These adjustments are of a trial and error nature and when not properly made cause a malfunction. This can result in damage, hand operation and further loss of time.

In addition to this conversion problem, the present injectors frequently failed to insert the rivet slug into the finger mechanism, in which case the slug falls to the work surface and the photoelectric interlock halts the automatic cycle. The operator must actuate the injector under manual control to insert another slug into the finger mechanism and resume the automatic mode of operation. An unreliable return spring may fail to complete the reciprocating action of the injector mechanism and the cycle may be repeated without the slug in proper position. Repetitive manual operation is again necessary to pick up the next slug from the delivery tube.

SUMMARY OF THE PRESENT INVENTION The improved rivet slug injector of the present invention provides for interchangeable adapter units to quickly, easily and accurately convert the injector for use from rivets of one diameter to rivets of another diameter. The same basic injector unit may thus remain intact and the conversion problems of previous injectors are thus eliminated. Proper alignment is maintained without trail and error adjustments and the need to remove and replace the photoelectric interlock structure. .No dismantling and realignment is necessary. The injector has a body to which is fastened a double acting air cylinder which extends and retracts a blade between an extension block and spring closed gate. Slugs from a delivery tube drop down onto the adapter and in front of this blade for movement past a photoelectric cell and into the fingers of a finger mechanism which inserts the slug into a hole drilled on a workpiece. A pointer for the corresponding rivet slug diameter is permanently attached to each adapter and indicates slug length adjustment on the appropriate scale stamped on the side of the body.

. 2 I BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the injector with hidden parts in dashed lines and related apparatus in phantom lines;

FIG. 2 is a perspective view of the front portion of the injector;

FIG. 3 is an elevational view;

FIG. 4 is a partial sectional plan view taken along the line showing the relationship of the end of the injector with the finger mechanism; and

FIG. 5 is a perspective view of the replaceable adapter unit with its associated blade shown in phantom lines. 1

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to FIG. 1 there is shown a body 10. This body preferably is a rectangular machined part or casting having a rear portion removed so that a double acting air cylinder 12 may be fitted therein. This cylinder 12 has the usual pneumatic conductors 14 and 16.at either end of the cylinder for longitudinal movement of a piston rod 18 in the oscillatory actuation of .the injector blade. A vertical slot 20 within the body 10 permits a blade 22 to move with the piston rod 18 in an oscillatory motion shown by the double arrow 24. A clevis 26 interconnects the blade 22 with the piston'rod 18 for actuation. I

Affixed to the body 10, such as by screws 30, is a tube base 32 having a further mounting support 34 affixed thereto. A rivet slug delivery tube 36 is secured to the tube base 32 such as by welding, for example and has its end 38 terminating at a point above the lower surface of the tube base 32. Rivet slugs are fed through this delivery tube by a gravity feed and dropped down from the delivery tube end 38 onto the upper surface 40 of an adapter unit 42 in front of the leading edge 21 of blade 22 when the blade 22 has moved rearwardly of the delivery tube 36. In FIG. 1 the blade 22 is shown in an intermediate position after having moved a rivet slug 44 forwardly in its forward stroke. When blade22 is in its rearwardmost position, an extension block 46 forwardly of body 10, and a spring loaded gate 48, with a vertical groove 49 therein and pivotally mounted to the front portion of body 10 prevent the rivet 44 from falling off the shelf 40 of the adapter 42 prior to the forward movement of the blade 22. This extension block 46 formerly was removable to provide access in replacing the injectors when a change in rivet size was desired. Spring gate 48 is pressed outwardly by the adapter 42 and blade 22 in their forward movement. A captive screw 50 is used in making a' vertical adjustment of the adaptor 42 relative to the blade 22 to accommodate the various lengths of the rivet 44. There are indicia markings 52 on the side of the body 10 and a pointer 54 connected to the adapter 42 is used in determining the vertical height to accommodate the predetermined rivet lengths.

Although not part of the present invention but used in conjunction therewith, is an electric eye mechanism that insures that a rivet has been passed by the blade 22 to a spring finger mechanism, not shown. This photoelectric mechanism is shown in phantom lines as consisting of a light source 56 secured to a support arm 58 attached to a mounting bracket 60 and a photoelectric cell 62 attached to a support arm 64 on bracket 60.

In one embodiment mounting bracket 60 extends rearwardly of tube base 32 and is fastened to the top of the injector body 10. The light source 56 projects a light onto the cell 62 in the well known manner, and this light source is interrupted upon the passage of the rivet 44 therebetween. This, in turn, actuates appropriate structure to accomplish the riveting operation. In one embodiment the electric eye signal starts a drilling operation.

A perspective view of the front portion of the injector is shown in FIG. 2. Here is shown piston rod 18 and clevis 26 for attachment to the blade 22. The piston and blade move longitudinally through a slot 20 between the outer walls of body 10. Tube base 32 is mounted on the top of body portion by means of screws 30. A support 34 interconnects thetube base to other mounting structure. The rivet slug delivery tube 36 is connected to the base 32. A leaf spring 68 urges gate 48 inwardly into contact with the extension block 46 and is pried outwardly upon the passage of rivet 44 and blade 22in the forward stroke.

The elevational view in FIG. 3 more clearly shows the operation of the 'rivetslug injector. As previously explained, the body 10 has a double acting air cylinder 12 mounted therein. Tube base 32 is shownmounted on the top and underneath this base isthe blade 22 fastened by the clevis 26 to the piston rod 18 for longitudinal movement under the rivet slug delivery tube 36. Adapter 42 is fastened to the blade 22 by means of a captive screw 50, the rotation of which makes a vertical adjustment between the adapter and the blade.

Guide bars 70 permit vertical relative movement while carrying the adapter 42 with the blade 22 in its longitudinal movement. Adapter 42 extends forwardly from the blade 22 to provide a shelf 40 upon which the rivet 44 is positioned when it drops down from the tube 36 when blade 22 is retracted rearwardly of the tube. When forward movement is imparted by the piston rod 18, the leading edge 21 of blade 22 pushes rivet 44 from groove 49 forwardly past the springretained gate 48. The adapter 42 and pointer 54 are carried with the blade 22. An intermediate position of the rivet movement is shownby dotted line 72 and its full forward position is shown at 74 where it is retained by a spring biased finger mechanism 76. This finger mechanism frictionally retains the rivets in the position shown by rivet 74 while hammer 78 performs the riveting operation. The actuation of the air cylinder 12 to initiate the forward movement of the blade 22, in one embodiment, is caused by a limit switch, not shown, tripped by a horizontal movement of the finger mechanism 76 toward the blade to receive the injected rivet.

As can be seen in the plan view in FIG. 4, the electric eye has its light source 56 and photoelectric cell 62 between the finger mechanism 76 and the end of gate 48 and extension block 46 so that as the blade 22 pushes the rivet 44 past the position shown by dotted line 72, appropriate signals are generated so that the riveting operation may be made after the rivet has been positioned within the fingers at position 74. The fingers of this finger mechanism 76 are outwardly urged by the rivet slug which is frictionally retained by them until the riveting operation has taken place.

The adapter unit is shown in FIG. 5. Here the double acting air cylinder 12 appears in phantom lines with the piston rod 18 and the blade 22 that is interconnected with the piston rod by means of clevis 26 for longitudinal actuation. The adapter 42 is a rectangular plate positioned forwardly and below the forward edge of the blade and is connected thereto by guide bars which permit vertical adjustment therebetween. The vertical adjustment is accomplished by a captive screw 50 whose head is frictionally retained by a leaf spring lock 82. Upon manual rotation of the head 80, the

screw 50 moves the adapter 42 vertically relative tothe from each other in the thickness of the adapter or in the vertical elevation of the table 40 with respect to the blade 22. The injector unit thus is a simpler mechanism with greater reliability and in its applicability to a variable operating need where formerly separate devices werenecessary. Interchangeable adapters permit rapid conversion to accept alternate slug diameters without replacing the entire ejectorassembly and realigning critical parts by a trial and error process.

Having thus described one form of the invention, it is to be understood that various modifications will readily occur to one skilled in the art and that it is to be understood that these variations are to be considered as art of the present invention.

Iclaim:

l. A rivet'slug injector comprising a body having an open ended vertical slot therein,

a blade longitudinally movable within said slot,

means for actuating said blade,

a rivet slug delivery tube affixed to said body over said slot and adapter to drop rivet slugs therein in upstanding orientation,

said blade having an adapter unit affixed thereto to provide an upper horizontal surface forwardly of said blade to receive the base ends of said rivet slugs, said adapter unit being movable with said blade and vertically adjustable relative thereto,

said blade being horizontally movable to a first position out of vertical alignment with said tube with said upper surface being positioned thereunder, said blade being horizontally movable under said tube to prevent further droppage of rivet slugs until said blade returns to said first position, said blade being horizontally movable under said tube to a second position where the rivet slug carried thereby may be removed, and

a spring biased gate closing said open end of said slot when said blade is in said first position, said gate having a vertical groove along the inner surface thereof into which said rivet slug is positioned upon dropping from said delivery tube.

2. A rivet slug injector as in claim 1, said adapter unit being connected to said blade through guide bars and a captive screw for adjusting vertical spacing therebetween,

said guide bars fitting into vertical apertures in the top of said adapter unit and in the bottom of said blade,

said adapter unit having indicating means thereon overlying indicia on said body to indicate vertical 5 adjustment of said adapter unit for selected lengths of rivet slugs.

Claims

1. A rivet slug injector comprising a body having an open ended vertical slot therein, a blade longitudinally movable within said slot, means for actuating said blade, a rivet slug delivery tube affixed to said body over said slot and adapter to drop rivet slugs therein in upstanding orientation, said blade having an adapter unit affixed thereto to provide an upper horizontal surface forwardly of said blade to receive the base ends of said rivet slugs, said adapter unit being movable with said blade and vertically adjustable relative thereto, said blade being horizontally movable to a first position out of vertical alignment with said tube with said upper surface being positioned thereunder, said blade being horizontally movable under said tube to prevent further droppage of rivet slugs until said blade returns to said first position, said blade being horizontally movable under said tube to a second position where the rivet slug carried thereby may be removed, and a spring biased gate closing said open end of said slot when said blade is in said first position, said gate having a vertical groove along the inner surface thereof into which said rivet slug is positioned upon dropping from said delivery tube.

2. A rivet slug injector as in claim 1, said adapter unit being connected to said blade through guide bars and a captive screw for adjusting vertical spacing therebetween, said guide bars fitting into vertical apertures in the top of said adapter unit and in the bottom of said blade, said adapter unit having indicating means thereon overlying indicia on said body to indicate vertical adjustment of said adapter unit for selected lengths of rivet slugs.