US3646800A

US3646800A - Mandrel rivet-setting tool

Info

Publication number: US3646800A
Application number: US10891A
Authority: US
Inventors: Alan Martin
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-02-12
Filing date: 1970-02-12
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A mandrel rivet-setting tool which provides for ready adjustment in the gripping strength of the jaws and provides, if desired, means for collecting the mandrels. The tool may be used for rivets having mandrels formed over a wide range of diameters and of a range of materials.

Description

I United States Patent 1151 3,646,800 Martin 1 Mar. 7, 1972 [54] MANDREL RIVET-SETTING TOOL 3,107,806 10/1963 Van Hecke ..72/391 72 Am. Mam-.1, 44 Lame. 1313,5160, 33228;? 35132? 52221? 1111:3533} Mass- 0267 3,363,445 1/1968 Sanders ..72/391 221 Filed: Feb. 12, 1911) 3,426,572 2/1969 Lahnston... .....72/391 3,457,763 7/1969 Freeman ..72/391 NW NW 10,391 3,491,578 1/1970 Biermann ..72/391 Primary Examiner-Charles W. Lanham [52] US. Cl. ..72/391 Assistant Emminer oene P Crosby 51 Int. (:1... 821d 9/05 Ammy Bessie upper [58] Field ofSearch ..72/39l, 114,467

ABSTRACT [56] References Cited A mandrel rivet-setting tool which provides for ready adjust- UNITED STATES PATENTS mem in the gripping strength of the jaws and provides, if desired, means for collecting the mandrels. The tool may be E1110 used for rivets having mandrels fonned over a wide range of 3,359,777 12/1967 Lee" ..72l391 diameters and ofa range ofmaten-ah 3,095,106 6/1963 M0rr1son.. ...72/391 3,100,578 8/1963 Halverson ..72/391 7 Claims, 13 Drawing Figures FATENTEDHAR (I972 8,646,800

sum 1 OF 3 IN VE N TOR Q I AlonMortin g BY/3 M /77% PATENTEDMAR H972 sum 3 [IF 3 Fig.IO

5 m f HIHHH 7 INVENTOR Alon Martin plication of a predetermined pulling force. A short, flanged tubular shank is positioned around the mandrel at the headend. When the shank is inserted into aligned holes in the workpieces to be joined and the mandrel is pulled away from the head, the head spreads out the shank to lock the workpieces between the resulting flattened deformed end of the shank and its flange, and then to snap off the mandrel from the head. The

mandrel is then removed from'the tool and discarded.

Several types of tools have been developed for inserting and actuating these mandrel rivets. (See for example U.S. Pat. Nos. 3,280,615, 3,324,700, 3,328,985 and 3,399,561); It is the purpose of this invention to provide an improved tool, particularly one which can grip and hold a mandrel prior to insertin g the rivet shank into the workpieces, which can be constructed to provide automatic ejection of the mandrel into a collector, and in which the grip can be adjusted for different mandrel metals.

It is therefore a primary object of this invention to provide an improved manually operated handtool for setting-mandrel rivets. It is another object to provide a tool of the character described which lightly grips the mandrel to hold the rivet so that it may be inserted while held by the tool into'a workpiece in any orientation with respect to the tool operator. An additional object of the invention is to provide a tool which may, if desired, be readily adjustable both with regard to the'manner in which the mandrel is removed and the force exertableby the gripping jaws on the mandrel. Other objects of the invention will in part be obvious and will in part be apparent hereinafter.

The invention accordingly comprises the features of construction, combination of elements and arrangement of parts which will be exemplified in the constructions hereinafter described and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying;

drawings in which:

FIG. 1 is a side view of the tool of this invention;

FIG. 2 is an end view of the tool;

FIG. 3 is a cross section of the rivet-holding end of the frame;

FIG. 4 is a cross section of that portion of the tool where the frame and actuating handle are joined for pivotal movement taken along line 4-4 of FIG. 1;

FIG. 5 is an enlarged, detailed cross section of one embodiment of the rivet-holding and actuating mechanism showing the insertion of a rivet therein;

FIG. 6 shows the mechanism of FIG. 5 in its mandrelgripping and pulling position;

FIGS. 7 and 8 are perspective and cross-sectional views of one of the jaws used in gripping;

FIG. 9 is a top planar view of a pair of the jaws;

FIG. 10 is a fragmentary cross section of another embodiment of the rivet-holding and actuating mechanism using a threaded ring to adjust the compression of the spring;

FIG. 11 is a top planar view ofthe ring in FIG. 10;

FIG. 12 illustrates the incorporation-of a mandrelcollector in the embodiment of FIG. 10; and

FIG. 13 is a fragmentary cross section of another embodiment of the rivet-holding and actuating mechanism having means for adjusting the compression of the spring and mandrel-collection means.

The handtool of this invention is shown in side and and views in FIGS. 1 and 2. It will be seen to be formed of a frame 10, an actuating handle 1! and a rivet-gripping and pulling mechanism 12. The frame 10 and actuating handle II are joined for pivotal motion with respect to each other, and the rivet-grippingv and pulling mechanism I2 is joined to the actuating handle 11 for axial motion within the frame 10.

The. frame 10 comprises a forward head section 15, a fulcrum extension member 16 having an opening 17 for a bushing and a flat stop member 18, and an'elongated curved fingerengaging handle 19 which may be partially covered with a sheath 20 having a good gripping surface. The actuating, palm-engaging handle 11 comprises a forward section which is bifurcated into two

arms

26 and 27 between which the fulcrum extension member l6-is positioned. Actuating handle 11 has a curved gripping end 30 which begins with an enlarged section 31 and is covered by a sheath 32 having a good gripping surface. The combination of the curved handles, the upper of which has the enlarged section 31, results in a comfortable grip for the user while maintaining his hand in the proper position. Threaded bores are provided along the top of the actuating handle for carrying anvils such as 34,, 35 and 36 of various bore diameters.

The pivotal connection between the finger-engaging handle 10 and the actuating handle 11 is made through a pivot pin 40 (see FIG. 4) which is positioned within a bushing 41, located in opening 17, and in two

flanged bushings

42 and 43 located in appropriately sized

openings inarms

26 and 27. The pin is locked with suitable snaprings 44 to prevent its axial movement.

A chamber 51 is defined within the head section of the frame (FIG. 3). This chamber is of a configuration which permits axial movement of the cylindrical mandrel-gripping and pulling mechanism 12. The chamber 51 is open at the top and has a threaded opening 52 at what may be termed the muzzle end of the head 15. This threaded opening is adapted to receive a threaded anvil 33, as willbe subsequently explained. The lower portion of the chamber has a frustoconical configuration 53 defined by a slanting wall 54.

FIG. 5 is a detailed cross section of the mandrel-gripping and pulling mechanism in position to receive the mandrel, i.e.,

with the actuating arm 11 pivotedto achieve maximum spacing from the finger-engaging handle which means that the mandrel-gripping and pulling mechanism 12 is in its lowermostposition. In this condition, the mandrel of the rivet may be readily inserted. Then by merely permitting the actuating handle to drop slightly through a very small arc the mandrel is held firmly in the tool, permitting the tool to be used as the means for introducing the rivet head and shank into the holes of the workpieces. This ability of the tool to hold the mandrel means that the rivets may be easily used for joining workpieces which would normally be in an awkward location if the rivet had to be hand-held in place until the tool was brought into position.

In FIG. 5 in which like tool components are identified by like reference numerals used in FIGS. 1-4, the rivet is seen positioned with respect to two

workpieces

58 and 59 which are to be joined. The rivet is comprised of a mandrel 60 which terminates in a head 61 which is joined to it in a manner to require a predetermined amount of force to break them apart. A tubular shank 62 having a flange 63 is slipped over the mandrel and attached to the head. As the mandrel is pulled, it causes the head to deform and flatten out the shank, thus locking the

workpieces

58 and 59 together between the flange and deformed and flattened side of the shank.

Thev mandrel-gripping and pulling mechanism is contained within a sleeve 65 which defines an actuator bore 66. The sleeve 65, at its upper end, is pivotally mounted to

arms

26 and 27 by means of

pivot pins

67 and 68 which are partially threaded for screwing into the arms and being locked thereto. In the embodiment of FIGS. 5 and 6, these pivot pins extend through thesleeve wall and into the actuator bore to serve as spring retaining means as described below. The sleeve has a generally frustoconical configuration at its lower end. The outer surface 70 (FIG. 6) of this lower part of the sleeve essentially corresponds to the frustoconical configuration of slanting wall 54 of the inner wall of chamber 51. The lower inner wall 72 of the sleeve is also of a frustoconical configuration, the angle which it forms with the central axis of the sleeve being smaller than that formed by the outer surface 70. Since the sleeve must ride up and down on the conical surface 73 of the anvil 33 the lower edge 74 of the sleeve is cut at an angle to provide a surface which makes contact with anvil surface 73.

The anvil 33 is threaded for engagement with the threads of opening 52, and it has a bore 75 sized to permit the mandrel 60 of the rivet to be passed through it. The

anvils

34, 35 and 36 have bores of varying diameters to accommodate differentsized mandrels. They are, of course, readily interchangeable.

The mandrel is gripped between two, essentially semicircular jaw pieces 78 which are detailed in FIGS. 7, 8 and 9. When assembled in the sleeve as in FIGS. and 6, the jaw pieces form an essentially frustoconical configuration corresponding essentially to that defined by the inner wall 72 of the lower section of the sleeve and define between them a threaded or serrated mandrel-gripping channel 80. Each, essentially semicircular jaw piece is cut to have a major upper planar surface 81 which slants downwardly toward the central axis of the channel. It is preferred that this major upper planar surface 81 be intersected by a minor planar surface 82 which may slant in the same manner but at a lesser angle which approaches 90 with the plane of the central axis. The presence of the minor planar surface 82 cases the opening of the jaws when a force is applied to the planar surface 81. In a similar manner the lower jaw pieces are cut to have a major lower planar surface 83 which slants upwardly toward the central axis of the channel and which is intersected by a minor planar surface 84 which may slant in the same manner but at a lesser angle which approaches 90 with the plane of the central axis. The angle at which the major planar surface is cut is chosen so as to achieve contact between the planar surface 83 and the conical surface 73 of the anvil against which it rides. The minor planar surface 84 serves the same general purpose as the minor planar surface 82.

A jaw actuator member 88 in actuator bore 51 is positioned to apply force through contact of its inclined lower surface 89 with the major planar surfaces 81 of the jaws. This actuator member has a bore 90 running throughout its length, this bore being of a diameter such as to permit passage of the largest sized mandrels 60. The upper surface 91 of the jaw actuator member and those portions of the pivot pins 67 and 68 which extend into the actuator bore serve as means to retain the compression spring 92 in force applying relationship to the jaw actuator member and through it to the jaws.

In operation, when the actuating handle 11 is raised upwardly from handle 10, sleeve 65 is moved downwardly to the position illustrated in FIG. 5. Force applied by spring 92 through jaw actuator 88 maintains the jaws in contact with sleeve surface 72 and anvil surface 73. In this position, the jaws are spread out, the gripping channel 80 is widened and the mandrel slips readily into place as shown in FIG. 5.

Merely by permitting actuating handle 11 to fall without any force being applied to it raises the sleeve 65 sufficiently to cause the jaws to lock the mandrel and the rivet in place. This loaded" position prior to insertion of the shank into the workpieces is a condition intermediate between the two positions shown in FIGS. 5 and 6.

When the rivet is to be set, pressure is applied to handle 11 causing it to pull the sleeve 65 with respect to the frame, and causing the jaws to grip the mandrel. This results first in deforming the shank to a somewhat flattened state 64 and then in snapping the mandrel from the head. Through proper alignment of the fulcrum locus (pivot pin 40) with respect to the pivot axis of pivot pins 67 and 68, the mandrel-pulling mechanism withdrawsthe mandrel in an essentially straight condition. This in turn means that the mandrel is easily removed either by permitting it to fall out of the tool or by automatically discharging it into a mandrel collector. Stop 18 limits the extent to which the handles may be forced toward each other, thus preventing injury to fingers which might be caught between the handles. The rivet mandrel may be then removed through the anvil bore or through the top of the sleeve.

It may be advantageous to be able to adjust, in any one tool, the amount .of force which is applied by the jaws in gripping the mandrel. Thus if the mandrel is made of aluminum this force is desirably less than if it is formed of, say, stainless steel or some other harder metal. In the case of a relatively soft" metal such as aluminum it is desirable to use less force to minimize the build up of metal in the serrations of the jaws. Excessive metal buildup in these serrations requires that the jaws be replaced. In the case of the harder metals, it is of course necessary to apply more force to assure gripping of the mandrel. The tool modifications illustrated in FIGS. 10-13 provide means for adjusting the gripping force in addition to the interchanging of springs of various compressive strengths.

In FIG. 10, in which like reference numerals are used to identify like components in FIG. 5, the upper spring-retaining means is a threaded ring 95 adapted to engage threads 96 cut within the inner wall of sleeve 65. The position of ring 95 may be used to exert more or less compressive force on spring 92. The ring must have some way to engage a screwing mechanism for locating it into its desired position, such as notches 97 (FIG. 11). The pivot pins 67 and 68 may terminate within the sleeve wall as shown since they are not used as a spring-retaining means as in FIG. 5.

FIG. 12 illustrates the use of the ring 95 to adjust the gripping strength and the incorporation of a rivet collector 100 which for convenience may be joined to or integral with the ring 95. In using tools to set rivets of the type described it is usually customary to permit the mandrels to fall out of the tool into the work area. This is highly undesirable from the point of view of personal safety for they can cause serious falls when stepped on. The collector 100 of FIG. 12 prevents such hazards and may be used in one of two different modes. If a spring is used which has normal compressive strength the mandrel may be collected by merely turning the tool over to permit the mandrel to fall freely into collector 100. The second proper location mode of operation is based upon the use of a weaker spring which, when the mandrel is snapped from the head, causes the mandrel to be impelled into the collector 100. The relative strength of the spring may be adjusted by the properlocation of the ring.

In the modification of FIG. 13, the pivot pins extend into the sleeve as in FIG. 13. These pins are used to engage one of a series of grooves 101, I02 and 103 in a ring member 104 which is adapted to fit into the sleeve and serve as the spring retaining means. By engaging the proper groove, a predetermined force is applied to the spring. There may, of course, be any number of grooves or holes, and the ring 104 may be attached to or integral with a mandrel collector 105.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained, and, since certain changes may be made in the above apparatus without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Iclaim:

l. A mandrel rivet-setting tool, comprising in combination a. a frame having integral therewith a fulcrum extension member and an elongated finger engaging handle;

b. a chamber defined within a forward head extension of said frame, said chamber being open at the top and having a frustoconical configuration at its muzzle end which terminates in a threaded opening in said frame;

c. an actuating, palm-engaging handle bifurcated at its actuating end into two arms, said actuating handle being pivotally connected to said frame through said fulcrum extension member positioned between said arms;

d. a sleeve defining therein an actuator bore, said sleeve being slideably movable within said chamber and extending beyond the length of said chamber, said sleeve having an outer frustoconical configuration essentially corresponding to the configuration of said chamber at its muzzle end and an inner lower frustoconical configuratron;

e. an anvil having a conical contacting surface and a bore of a predetermined size adapted to permit the passage of the mandrel of a rivet therethrough, said anvil being threaded for screwing into the threaded opening of said frame;

f. a pair of jaws within said actuator bore, said jaws when assembled having an outer surface configuration which essentially conforms to the inner lower frustoconical configuration of said sleeve and which define between them a threaded passage adapted to grip a rivet mandrel, each of said jaws being cut to define upper and lower inclined planar surfaces, the upper planar surface slanting downwardly toward the central axis of said sleeve and the lower planar surface slanting upwardly to said central axis and being adapted to at least in part engage the conica contacting surface of said anvil;

g. a hollow jaw actuator member totally within said actuator bore and having a jaw-contacting surface adapted to achieve surface contact with said upper planar-slanting surfaces of saidjaws;

h. pivot means joining said sleeve to said actuating handle between said arms of said handle;

i. spring retaining means associated with the upper end of said sleeve;

between the upper surface of said jaw actuator and said spring retaining means.

2. A mandrel rivet-setting tool in accordance with claim 1 wherein said pivot means joining said sleeve to said actuating handle are pivot pins which extend through said sleeve into said actuator bore and serve as said spring-retaining means.

3. A mandrel rivet-setting tool in accordance with claim 1 wherein said spring-retaining means comprises a threaded ring and the upper inner surface of said sleeve is threaded to receive said threaded ring, whereby the compressive strength of said spring may be adjusted.

4. A mandrel rivet-setting tool in accordance with claim 3 wherein mandrel-collecting means is affixed to said threaded ring.

5. A mandrel rivet-setting tool in accordance with claim 1 wherein said pivot means joining said sleeve to said actuating handle are pivot pins which extend through said sleeve into said actuator bore and said spring-retaining means comprise a ring member having grooves or holes adapted for engagement by said pivot pins whereby the compressive strength of said spring may be adjusted.

6 A mandrel rivet-setting tool in accordance with claim 5 wherein said ring member has mandrel-collecting means attached thereto.

7. A mandrel rivet-setting tool in accordance with claim I wherein the means for pivotally connecting said actuating handle with said frame comprises a bushing in said fulcrum extension member, flanged bushings in said arms and a pivot pin extending through said bushings and locked to prevent axial motion.

Claims

1. A mandrel rivet-setting tool, comprising in combination a. a frame having integral therewith a fulcrum extension member and an elongated finger engaging handle; b. a chamber defined within a forward head extension of said frame, said chamber being open at the top and having a frustoconical configuration at its muzzle end which terminates in a threaded opening in said frame; c. an actuating, palm-engaging handle bifurcated at its actuating end into two arms, said actuating handle being pivotally connected to said frame through said fulcrum extension member positioned between said arms; d. a sleeve defining therein an actuator bore, said sleeve being slideably movable within said chamber and extending beyond the length of said chamber, said sleeve having an outer frustoconical configuration essentially corresponding to the configuration of said chamber at its muzzle end and an inner lower frustoconical configuration; e. an anvil having a conical contacting surface and a bore of a predetermined size adapted to permit the passage of the mandrel of a rivet therethrough, said anvil being threaded for screwing into the threaded opening of said frame; f. a pair of jaws within said actuator bore, said jaws when assembled having an outer surface configuration which essentially conforms to the inner lower frustoconical configuration of said sleeve and which define between them a threaded passage adapted to grip a rivet mandrel, each of said jaws being cut to define upper and lower inclined planar surfaces, the upper planar surface slanting downwardly toward the central axis of said sleeve and the lower planar surface slanting upwardly to said central axis and being adapted to at least in part engage the conical contacting surface of said anvil; g. a hollow jaw actuator member totally within said actuator bore and having a jaw-contacting surface adapted to achieve surface contact with said upper planar-slanting surfaces of said jaws; h. pivot means joining said sleeve to said actuating handle between said arms of said handle; i. spring retaining means associated with the upper end of said sleeve; j. a spring within said actuator bore held in compression between the upper surface of said jaw actuator and said spring retaining means.

6. A mandrel rivet-setting tool in accordance with claim 5 wherein said ring member has mandrel-collecting means attached thereto.

7. A mandrel rivet-setting tool in accordance with claim 1 wherein the means for pivotally connecting said actuating handle with said frame comprises a bushing in said fulcrum extension member, flanged bushings in said arms and a pivot pin extending through said bushings and locked to prevent axial motion.