US3101858A

US3101858A - Rivet feeding apparatus

Info

Publication number: US3101858A
Application number: US83282A
Authority: US
Inventors: Brewer Clifford Edmund
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-01-20
Filing date: 1961-01-17
Publication date: 1963-08-27
Anticipated expiration: 1980-08-27

Description

Aug. 27, 1963 Filed Jan. 17, 1961 C. E. BREWER RIVET FEEDING APPARATUS 3 Sheets-Sheet 1 Aug. 27, 1963 c. E. BREWER RIVET FEEDING APPARATUS 5 Sheets-Sheet 2 Filed Jan. 17, 1961 Aug. 27, 1963 'c. E. BREWER RIVET FEEDING APPARATUS 3 Sheets-Sheet 5 Filed Jan. 17, 1961 United States Patent 3,101,858 RIVET FEEDING APPARATUS Cliiford Edmund Brewer, Parkstone, Dorset, England (19 Upton Road, Fleets Bridge, Poole, Dorset, Eng- This invention relates to riveting apparatus and more particularly to an apparatus adapted to handle so called pop rivets. Pop rivets are of the type having a flanged head portion which is adapted to secure together the articles to be joined and a mandrel portion of mild steel which is connected to the head portion. The pop rivetsfurther may be of two types; in a first of which the head is pulled through the rivet to upset the same and secure the articles to be joined; and in the second type tension is exerted on the mandrel to cause upsetting of the rivet and the mandrel is broken 01f whenthe rivet is installed. Consequently, the mandrel is waste portion and solely facilitates handling and installation. Thus it may be said that pop rivets are hollow rivets having an axially projecting shank associated therewith in such a manner thatwith the rivet in position in a workpiece an appropriate tension exerted on the mandrel will result in upsetting of said rivet and also in removal of a portion of said mandrel therefrom, a head portion of the mandrel remaining in the hollow rivet. Pop rivets are used extensively in the aircraft industry for installations which are accessible-only 'firom one side.

According to the invention the riveting apparatus comprises a rotor adapted to carry a plurality ofi chucks in angu'larly spaced relationship, each such chuck being capable 0t receiving the mandrel of a pop rivet, means for imparting a step by step motion to said rotor whereby successive chucks will be moved successively from a feed position at'which a rivet may be fed thereinto to an operative position and thence to la mandrel dischargeposition and means adapted when each chuck is in the operative position to impart a retractive movement thereto sufiicient in the case of use with rivets of the first type to remove the mandrel from the rivet while in the second case sufficientto upset the rivet and remove a portion of the mandrel. Conveniently the rotor will carry hour chucks spaced apart at 90 and the arrangement is such that on completion of each operative cycle of the apparatus the rotor will have been moved through 9i). Preferably means will be provided whereby on operahon of the apparatus the rivet will be fed automatically mandrel first into each chuck when the latter is in the feed position. i

In order that the invention may be clearly understood and readily carried into eliect one constructional em bodiment thereof will now be described with reference to the accompanying drawings in which:

FIGURE 1 is a front elevational view of a riveting apparatus,

FIGURE 2 shows a section on the line 2- -2 of FIG- URE 1,

FIGURE 3 is a cross sectional view on a larger scale of a rotor assembly incorporated in the apparatus shown in FIGURES 1 and 2,

FIGURE 4 is a section on the line 44 of FIG- URE 3,

FIGURE 5 is a sectional view on yet a larger scale illustrating the construction of a chuck incorporated in the aforesaid rotor assembly,

FIGURE 6 is a perspective View of a rivet feed mechanism which is mounted at the upper part of the apparatus illustrated in FIGURE 1,

ice

FIGURE 7 is a front elevational view of a part of the :feed mechanism,

FIGURES 8, 9 and 10 are plan views of a part of the feed mechanism and illustrate difierent stages in the operation thereof.

Referring now to the drawings Ill denotes a rotor which is supported for rotational movement about the axis-of a horizontal shaft 11. The shaft is supported for free rotation in a rigid frame structure designated generally by 12 such structure being mounted on a base plate 13 which is in turn supported on a table 15. Suspended from the base plate by means of rods 16 is a lower platform 17 adapted to support. a double acting pneumatic ram 18. Coupled to the ram 18 to be reciprocated vertically thereby is a rack 19 by means of which a step by step-rotational movement will be imparted to the rotor 10 as will be hereinafter made apparent.

The rotor 10 carries four chuck assemblies designated generally by 20 which are spaced apart through relatively to each other, the longitudinal axes of the chucks being disposed radially of said rotor. As will be clearly seen from FIGURE 5 each chuck assembly is located in a radially directed slot formed in the rotor Ill and comprises a body portion 21 which is slidable axially of the slot and is urged radially outwardly by means of a spring 22. Disposed coaxially within the body portion 21 so as to be capable of relative axial movement is a mandrel gripper element comprising a hollow sleeve portion 23 and resilient jaws 24 such jaws being externally tapered as shown and adapted to cooperate with a corresponding tapered seating formed internally of said body portion at the outer end thereof. The gripper element is urged forwardly relatively to the body portion 21 by means of a light spring 25 so that the jaws 24 will be urged into contact with the aforesaid tapered seating. 26 denotes a hollow cap member which is adapted to house the outer end of each chuck assembly, such members, which are so mounted on the rotor as to be readily removable and replaceable to allow of ready changing of the chucks, each being provided with a threaded bush 27 the bore of which is aligned with the longitudinal axis of the gripper element to allow passage of a rivet mandrel therethrough and into the latter. The construction is such that when the body portion 21 is in its extended position, which is the position which it normally assumes due to the action of the spring 22, the jaws 24- of the gripper element will be brought into resilient contact with the inner end of the bush 27. The arrangement is such that with the jaws 24 in contact with the bush 27 there will be slight additional forward movement ofthe body portion 21 under the action of the spring 22 so that the tapered seating will be moved forwardly relatively to said jaws thereby a-llowing them to assume an open position. This relative movement between the body portion 21 and the jaws 24 will result in compression of the spring 25. This condition will prevail in each chuck at all times except when the chuck is in the operative position and the rack 19 is moving downwardly as will be herein-after more fully described. When the chuck is in such position which is designated B in FIGURE 4 and the rack 19 is moving downwardly the body portion 21 will as hereinafter described be moved rearwardly so that the external tapering of the jaws 24 will cooperate with the tapered seating formed internally of said body portion and said jaws will be caused to close and to exert a grip on the rivet mandrel in the chuck. At its inner end the body portion 21 of each chuck assembly is provided with a transverse pin 28 adapted to project laterally from each side of the rotor 10. Each pin 23 may be so mounted as to be capable of free rotational movement about its longitudinal axis but preferably a freely rotatable roller as indicated at 29 will be mounted at each end thereof.

Fixedly mounted on the shaft 11 are two

circular discs

30, 31 which are disposed one at each side of the rotor 10. As will be seen from FIGURES 3 and 4 each of the

discs

30, 31 is formed at its inner face with a cam surface 32 with which the rollers 29 on the pins 28 of the chuck assemblies are adapted to cooperate as will be hereinafter made apparent. As indicated above the discs 3%, 31 are fixedly mounted on the shaft 11 so that they will move together as a unit and one of such discs, in this case the disc 30, is provided externally with a toothed sector adapted to cooperate with the rack 19.

The arrangement as so far described is such that on downward movement of the rack 19 (in all figures it is shown in its uppermost position) the discs 36), 31 will be moved angularly through 90 (clockwise as seen in FIGURE 4) while on upward movement of said rack said discs will move angularly in the reverse direction through 90 (counter clockwise as shown in FIGURE 4) back to their initial position.

As will be seen from FIGURE 4 the cam surface 32 on each of the

discs

30, 31 terminates in a shoulder 33 and referring now to that figure it will be appreciated that downward movement of the rack 19 will result in angular movement of the

discs

30, 31 clockwise. As the

discs

30, 31 move clockwise the cam surfaces 32 will cause the pin 23 and hence the body portion 21 of the chuck at position B to be retracted so that the gripper jaws 24 of that chuck will become operative to grip and exert a pull on the mandrel of a rivet present therein to secure the rivet in the work and also to remove the mandrel therefrom. As the rack 19 reaches the end of its downward movement the rollers 29 on the pin 23 of the chuck at position B will pass over the shoulders 33 and the spring 22 will be eifective to move the chuck assembly forwardly back to its initial extended position wherein the resilient jaws 24 will again be opened. In this position the shoulders 33 on the

discs

30, 31 will be located behind the chuck assembly at position B so that on upward movement of the rack 19 with consequent counter clockwise rotation of the

discs

30, 31 the rotor will then move with said discs through 90 so that the chuck assembly that was at position B will then be located at position C, at which point the mandrel previously removed at position B will fall by gravity from the chuck.

It may be mentioned here that rivet will be fed into a chuck at position A by apparatus hereinafter described, at position B the rivet will be secured in the work and the mandrel removed by the closing and subsequent retraction of jaws 24-, and at position C the spent mandrel will be ejected, the fourth position D being an idle position as far as each chuck assembly is concerned.

34 denotes a spring loaded stop which is adapted to cooperate in turn with the projecting cap elements 26 of the chuck assemblies on the rotor 10 in order positively to prevent any tendency of reverse rotational movement of the rotor. Thus stop 34 prevents clockwise movement as shown in FIG. 4, of the rotor during downward movement of the rack 19' as follows. During each desired angular movement of the rotor on upward travel of said rack one of the cap elements 26 will, move past the spring loaded stop 34 as the rack reaches the limit of its upward movement. The stop 34 immediately snaps into an operative position in the path of element 26 to prevent reverse angular movement of the rotor.

35 denotes a spring which is adapted to cooperate in turn with the projecting cap elements 26 of the chuck assemblies in order to prevent any tendency to over-running of the rotor on each 90 angular movement thereof. The spring 35 is mounted on an arm 36 which is connected to the rack 19 by any suitable means so long as the arm will move with the rack and will only be located in its operative position at appropriate times. The spring 35 therefore engages the cap element 26 and is of sufiicient strength to prevent more than a movement of element 26.

Mounted on the aforesaid arm 36 is an upwardly projecting cam rod 37 carrying two

cams

38 and 39 adapted to operate a rivet feed mechanism as hereinafter described. As indicated above the arm 36 is connected to the rack 19 so that the cam rod 37 will be reciprocated vertically with the latter and will thus be effective to actuate the feed mechanism in timed relation with the remainder of the apparatus so that as each chuck assembly reaches the position A a rivet will be fed thereto automatically. The rod 37 is conveniently provided with a longitudinally extending slot 40 in which a stationary pin, indicated at 41 in FIG. 2, is adapted to engage. The pin 41 is supported in the rigid frame structure and the arrangement is such that said rod will be effectively guided and maintained in a vertical path.

In the embodiment illustrated the rivet feeding mechanism comprises a hopper 42 adapted to hold a bulk supply of rivets such rivets being fed successively from said hopper down an inclined feed-way 43 one behind the other. The feedway essentially comprises two plates in spaced parallel relation with the mandrels of the rivets being accommodated in the space between the plates while the flanges on the heads of the rivets rest on and slide along the inclined edges of said plates. Disposed at the lower end of the feedway and slidable transversely relatively thereto into and out of an operative position wherein it will close the latter is a gate 44 such gate comprising an upstanding strip on a slide bar 45. At its rear end the slide bar 45 is provided with an upstanding lug 46 adapted to cooperate with the cam 39 on the rod 37. At its upper end the lug 46 carries a transverse bar with two laterally projecting lugs 47 adapted to provide anchorages for one end of each of two coiled tension springs 48, 49. The other ends of the springs 48-49 are anchored to laterally projecting lugs 50 carried by a transverse bar on an upstanding lug 51 on a second slide bar 52 which carries at its outer end a retaining and position block 53. The lug 51 on the slide bar 52 is adapted to cooperate with the cam 38 on the rod 37 and it will be appreciated that the

springs

43, 49 serve to maintain the lugs 46, 51 in contact with the respective cam surfaces 39, 38 on said rod. As will be seen from FIGURES 7, 9 and 10 the gate 44 is provided at its lower end with an out-turned lip 54 the purpose of which will be hereinafter made apparent.

The construction is such that when the rack 19 and hence the cam rod 37 are in their uppermost positions the gate 44 will be retracted due to the fact that the lug 46 on the slide bar 45 will be forced rearwardly by reason of the fact that it is then in contact with an increased thickness of said rod 37. Simultaneously the retaining and position block 53' will be in its advanced position by virtue of the fact that the lug 51 on the slide bar 52 is also in engagement with an increased thickness of the rod 37. This position is illustrated in FIGURES 7 and 8 and in such position a rivet will pass from the feedway 43 into the position shown in FIGURES 7 and 8 wherein the head of the rivet will engage and be supported by the block 53. As the rack 19 and hence the cam rod 37 move downwardly the gate will by reason of the relative positioning of the cam surfaces 38, 39 commence to move forwardly to shut off the feedway prior to there being any relative movement of the block 53 so that the rivet will still be supported as shown in FIGURE 7. With continued downward movement of the rack *19 and of the cam rod 37 the gate 44 will move progressively forwardly while the block 53 will move rearwardly as shown in FIGURES 9 and 10. At a predetermined point the block 53 will be moved clear of the head of the rivet which will then drop downwardly into the feed position wherein it will hang vertically with the flange on its head supported on the lip 54 of the gate 44. The arrangement is such that as the rivet falls into the feed position its mandrel will enter that chuck which is then at position A it being and to snap off and remove the mandrel.

understood that such chuck will have been brought to position A on the previous upward movement of the rack 19 there being no angular motion of the rotor on downward movement of said rack. When the rack 19 and the cam rod 37 are in their lowermost positions the gate 44- and the block 53 will be respectively fully projected and retracted as indicated in FIGURE 10. On upward movement of the rack 19 and the cam rod 37' there will by reason of the shaping of the

cam

38 and 39 initially be no movement of the slide bars 45 and 52 and hence of the gate 44, and block 53. However the rotor will move angularly and hence the chuck into which the rivet was fed will move from position A towards position B thereby removing the rivet from the feed mechanism. As the rack 19 and cam rod 37 continue to rise the slide bars 45 and 52 will be respectively retracted and projected so that at the end of the upward stroke the gate 44 will be fully retracted to allow passage of another rivet from the feedway 43 while the block 53 will be fully projected and will be effective to support such rivet as shown in 'FIG- URE 7. It will be appreciated that upon completion of the upward stroke of the rack 19 another chuck will have been brought into position A but as explained above actual feeding of the rivet into the chuck will not take place until the rack 19 and the cam rod 37 again move downwardly.

If desired a small spring such as is indicated at 55 may be provided in order to prevent undesired displacement of the rivet mandrels during feeding, such spring being strong enough merely to hold the rivet but not provide any resistance to removal of the same on rotation of the rotor. 56 denotes a slotted guide which will be engaged by the upper portions of the rivet heads as they reach the lower end of the feedway and will serve to maintain the rivets in the required position.

The apparatus above described is adapted to operate as follows.

On downward movement of the rack 19 a rivet will be fed into the chuck on the rotor which is at position A. Simultaneously the chuck at position B will be retracted to secure the rivet which is present therein in the work, On upward movement of the rack 19 the rotor will be rotated through 90 to bring the chuck previously at position A into position B such chuck carrying with it the rivet fed thereto by the feed mechanism. With this rotation another chuck will be brought into the rivet receiving position. With the newly loaded chuck at position B depression of the rack 19 and of the cam rod 37 will result in securing of the rivet and removal of the mandrel and in feeding of a rivet into the chuck then at position A. The next upward movement of said rack would result in bringing the chuck previously at position B into position C whereat the spent mandrel will fall from the chuck under the action of gravity. Thus during operation of the machine the rotor will have a step by step motion imparted thereto bringing the chucks successively from position A to B, thence to C and D and again to A and so on, the cycle being repetitive as long as the ram 18 is kept in operation. Furthermore it will be appreciated that each chuck will be supplied with a rivet at A and, will be operative to secure the rivet in the work at B and will discharge the spent mandrel at C.

Conveniently the machine may be provided with a bracket as indicated at 57 to form a locating means for Work to which rivets are to be applied.

What is claimed is:

1. Apparatus for setting rivets of the type having a mandrel, said apparatus comprising a plurality of chucks each including a pair of jaws normally spaced apart, a rotor supporting said chucks in angularly spaced relationship, each of said chucks being adapted for receiving the mandrel of one of said rivets between the jaws thereof, means for imparting a step by step motion to said rotor whereby said chucks are moved successively from a feed position at which one of said rivets is fed thereinto, to an operative position and thereafter to a mandrel discharge position, and means synchronized with the means for imparting the step by step motion for clamping the jaws of said chucks together in the operative position to grip the mandrel of a rivet in the respective jaws while applying a tension force to said mandrel to remove the mandrel from the rivet to provide a setting of the rivet.

2. Apparatus as claimed in claim 1 in which the rotor is mounted for free rotation and comprising cam means operatively coupled to said rotor and said chucks to retract said chucks in the operative position with the cam means rotating in a first angular direction and said rotor maintained at rest, while reverse angular movement of said cam means results in a corresponding angular movement of said rotor.

3. Apparatus as claimed in claim 2 wherein the cam means comprises a pair of disc members, each being disposed at opposite sides of the rotor and coaxial therewith, each of said members having an inner surface and cam track provided therein, follower means on each of said chucks in operative engagement with said cam tracks for retracting said corresponding chuck.

4. Apparatus as claimed in claim 3 comprising a transverse pin on the body portion and projecting laterally from opposite sides thereof, said pin cooperating with the cam tracks of the disc members with said corresponding chuck in the operative position.

5. Apparatus as claimed in claim 3 comprising a cap removably attached to the rotor for each of said chucks and enclosing the same, each of said caps having an aperture therein aligned with the respective chuck and enabling entry of the mandrel therein.

6. Apparatus as claimed in claim 2 wherein the rotor is provided with a radially directed slot for each of said chucks, each of said chucks being supported in one of said slots for limited radial movement, and resilient means in each said slot for normally maintaining the corresponding chuck in extended position.

7. Apparatus as claimed in claim 6 wherein each of said chucks comprises a body portion which is slidable in the corresponding radially directed slot in the rotor, said jaws constituting mandrel receiving and gripper means and being located in said body portion, said body portion and jaws defining cooperating surfaces whereby axial movement of the body portion relatively to the jaws will result in closure of the jaws.

8. Apparatus as claimed in claim 2 comprising a reciprocable rack, a toothed segment engaging said rack and operatively associated with said cam means to drive the same.

9. Apparatus as claimed in claim 8 comprising a double acting ram coupled to said rack for driving the same.

10. Apparatus as claimed in claim 2 comprising resilient stop means coupled to said rotor for preventing overrunning of the rotor on each angular movement thereof.

11. Apparatus as claimed in claim 2 comprising a resilient stop operatively associated with said rotor to permit rotation of the rotor in a first direction and to positively prevent rotation in the reverse direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,357,368 Wilkins Nov. 2, 1920 1,806,217 Rees May 19, 1931 1,997,438 Stimpson Apr. 9, 1935

Claims

1. APPARATUS FOR SETTING RIVETS OF THE TYPE HAVING A MANDREL, SAID APPARATUS COMPRISING A PLURALITY OF CHUCKS EACH INCLUDING A PAIR OF JAWS NORMALLY SPACED APART, A ROTOR SUPPORTING SAID CHUCKS IN ANGULARLY SPACED RELATIONSHIP, EACH OF SAID CHUCKS BEING ADAPTED FOR RECEIVING THE MANDREL OF ONE OF SAID RIVETS BETWEEN THE JAWS THEREOF, MEANS FOR IMPARTING A STEP BY STEP MOTION TO SAID ROTOR WHEREBY SAID CHUCKS ARE MOVED SUCCESSIVELY FROM A FEED POSITION AT WHICH ONE OF SAID RIVETS IS FED THEREINTO, TO AN OPERATIVE POSITION AND THEREAFTER TO A MANDREL DISCHARGE POSITION, AND MEANS SYNCHRONIZED WITH THE MEANS FOR IMPARTING THE STEP BY STEP MOTION FOR CLAMPING THE JAWS OF SAID CHUCKS TOGETHER IN THE OPERATIVE POSITION TO GRIP THE MANDREL OF A RIVET IN THE RESPECTIVE JAWS WHILE APPLYING