US2536573A - Clip driving machine - Google Patents

Description

Jan. 2, 1951 w. SCHAFROTH 2,536,573

CLIP DRIVING MACHINE Filed Aug. 5, 1949 4 Sheets-Sheet l INVEN TOR. MFA/[R el/Armor BY 29 Jan. 2, 1951 w, SCHAFRQTH 2,536,573

CLIP DRIVING MACHINE Filed Aug. 5, 1949 4 Sheets-Sheet 2 IN VEN TOR. [VERA/1? gums-20TH Jan. 2, 1951 w. SCHAFROTH CLIP muvmc MACHINE 4 Sheets-Sheet 3 Filed Aug. 5, 1949 ill I N V EV TOR. Wi/P/VE R f'cl-mmor -l Ja n. 2, 1951 w, SCHAFROTH 2,536,573

CLIP DRIVING MACHINE Filed Aug. 5, 1949 4 Sheets-Sheet 4 INVENTOR. WERNER fcHnFRm-g Patented Jan. 2, 1951 UNITED STATES PATENT OFFICE 19 Claims.

The present invention relates to a machine for driving clips and is concerned primarily with the driving of clips which may be employed for closing the flaps of cartons and similar purposes.

In the copending application of Werner Schafroth, Serial Number 108,846, filed August 5, 1949, and entitled Clip for, Fastening Pieces of Material Together, there is illustrated and described a clip of the particular type that is intended to be driven by the machine 'of this invention. A plurality of these clips are provided in the form of a continuous strip or magazine, and the machine of this invention is designed to operate on such a continuous strip of the clips.

In order to set forth the general nature of the functions required of the present clip driving machine, it is necessary to refer to certain salient features of construction of the clip itself. A strip of these clips is fashioned from a continuous strip of sheet metal. Each clip is of a generally rectangular formation and is joined to the next adjacent clips by a pair of narrow depressed necks at each end and which are located substantially at the opposite side edges of the strip. These necks are formed by striking out an opening that extends across the strip and which terminates at each end in converging edges which meet the necks thereat. Depressions are also struck inwardly from the outer side edges opposite to the converging edges aforesaid and the necks are depressed from the top so that when they are severed there is provided in effect a downwardly directed pointed tab at each corner of the clip.

Each clip is formed with a leg at each end which is struck from the metal strip and which is integrally joined to the main body portion of the clip by bends in the metal. Each leg comprises a pair of spaced struts. Integrally joined to the lower ends of these struts is a concaveconvex pointed tab which is slightly out of alignment with the legs and which are adapted to be bent into a position substantially parallel to the main body portion of the-clip. It is evident that the formation of these legs and pointed tabs carried thereby leaves an opening at each end of each clip, and it is also evident that when a clip is separated from the strip by severing the pair of necks which join the strip thereto, there is provided a recess between the pointed tabs which are left after the necks are severed.

In accordance with the present invention and also in accordance with the invention directed to the clip itself as disclosed and claimed in said copending application, it is intended that a long continuous strip of the clips be coiled into a roll which constitutes a magazine of such clips.

With these conditions in mind-the present in-' vention has in view as its foremost objective the provision of a clip driving machine of the type indicated which includes feeding mechanism that is designed to cooperate with such a magazine of clips.

In order for the machine to function in the manner intended it is necessary that the clip at the free end of the strip be advanced into position for severance and driving for each cycle of operation. This means that the feeding mechanism should operate with an intermittent or step by step motion. Thus, another object is to provide, in a clip driving machine of the character noted, feeding mechanism which is adapted to operate on a continuous strip of the clips with a step by step motion to advance the clip at the free end of the strip a distance substantially equal to the length of a clip.

In carrying out these broad objectives the machine is provided with a track which receives the strip of clips. When so received the clips are joined by the unsevered necks and the legs with the pointed tabs in a slightly inclined position with respect thereto extend outwardly in directions substantially normal to the main body portions of the clips. A feed wheel is operatively mounted and so disposed with relation to the track, that projections which extend outwardly from the feed wheel are received in the openings from which the legs and tabs are struck. Thus, rotation of the feed wheel causes movement of the strip of clips.

Another somewhat more detailed object of the invention is to provide spring means for rotating the wheel a predetermined distance for each cycle of operation. Various other more detailed objects and advantages of the invention are tied up with this phase of operation of the feeding mechanism.

Still another object of the invention is to provide, in a clip driving. machine of the type indicated, feeding mechanism which will accurately position the clip at the free end of the strip with relation to the apparatus which severs, drives, and bends the pointed tabs of the clips. Other more detailed objects and advantages of the invention are associated with the provision of mechanism for achieving this accurate positioning.

As above explained, the clip at the free end of the strip must be severed therefrom, the legs with the pointed tabs carried thereby driven into the pieces of material which are to be joined by the clip, and the pointed tabs bent. Thus, another highly important object is to provide, in a clip driving machine of the character indicated, a plunger assembly which includes means for severing the necks which join the clip at the free end to the strip, means for driving the legs into the material, and means for bending the pointed tabs, carried at the free ends of the legs after the latter are driven, into positions substantially parallel to the main body portion of the clip.

More in detail the invention has as an object the provision, in the plunger assembly of a clip driving machine, of shear elements adapted to engage the necks joining the clips on one face and to cooperate with fixed shear elements on the opposite face to sever the necks and thus separate the clip at the free end of the strip.

In order for this shearing operation to be properly carried out, it is necessary that the clip be supported at its free end. Thus, another object is to provide, in a clip driving machine of the type noted, means for supporting the free end of the clip while the necks at the opposite ends thereof are being severed. This means may be asociated with that portion of the feeding mechanism which accurately positions the clip at the free end of the strip.

Each leg of each clip comprises a pair of spaced struts of sheet metal. It is necessary that these struts be adequately supported during the driving operation. Important features and advantages of the invention are tied up with the manner in which these supporting members are operatively included in the plunger assembly.

In order for a clip driving machine of this type to meet the conditions of practical usage, it is necessary that all of the operations required of the several elements of the plunger assembly be performed on a single stroke of the plunger. As above explained the pointed tabs carried thereby must first be driven into the material prior to bending of the pointed tabs. This means that the bending of the pointed tabs is the final step of the driving operation and must be carried out after the legs are driven. With this condition in mind another highly important object is to provide, in a plunger assembly of a clip driving machine of the type noted, tab bending implements together with means for causing their effective operation after the legs have been driven home. This object is achieved by provid ing a lost motion connection between certain elements of the plunger assembly. Other detailed objects and advantages of the invention are tied up with the manner of achieving this lost motion connection which correlates the operation of the tab bending implements to the functions of the other elements of the plunger assembly.

Still another objective of the invention is to provide, in a clip driving machine of the character noted, means for tensioning the operating spring of the feeding mechanism as an incident to the operation of the plunger assembly. Thus, when the plunger assembly is driven to sever and drive a clip, the spring of the feeding mech anism is tensioned so that upon release thereof at the proper moment the feeding mechanism is actuated to bring the clip at the free end of the strip into effective position with respect to the plunger assembly.

Various other more detailed objects and advantages cf the invetnion such as arise in connection with carrying out the above noted ideas in a practical embodiment will, in part become apparent, and in part be hereinafter stated as the description of the invention proceeds.

The invention therefore comprises a clip driving machine which i adapted to operate on a continuous strip of clips which are joined by depressed necks in each side of the strip with each clip having a pair of outwardly extending legs carrying pointed tabs. The machine consists essentially of feeding mechanism for indexing the clip at the free end of the strip into proper position for severance and driving, together with a plunger assembly for severing the necks which join a clip to the strip, driving the legs with the pointed tabs thereon into the material, and bending the pointed tabs into positions substantially parallel to the main body portions of the clips.

For a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein:

Figure 1 is a view in side elevation of a clip driving machine designed in accordance with the precepts of this invention.

Figure 2 is a top plan view of the machine shown in Figure 1.

Figure 3 is a longitudinal vertical section through the plunger assembly with the feeding mechanism shown in elevation.

Figure 4 is a detailed view in side elevation of the feeding mechanism showing the wheel as locked against rotation.

Figure 5 is a top plan view of one of the clips per se.

Figure 6 is a view in side elevation of the clip shown in Figure 5.

Figure 7 is a transverse vertical section taken about on the plane represented by the line i-| of Figure l with a portion of the feed wheel broken away.

Figure 8 is another transverse vertical section taken about on the plane represented by the line 8-8 of Figure 1.

Figure 9 is a bottom plan view of the plunger assembly with the frame of the machine shown in section. This view is taken about on the plane represented by the line 99 of Figure 1.

Figure 10 is a transverse vertical section through the plunger assembly taken about on the plane represented by the line lO-lfl of Figure 2.

Figure 11 is a side view, somewhat diagrammatic, showing the initial phase of operation of the plunger assembly in carrying out the step of separating the clip at the free end of the strip from the strip.

Figure 12 is a view, somewhat similar to Figure 11, showing the plunger assembly immediately after the legs have been driven into the material; and

Figure 13 is still another view similar to Figures 11 and 12 showing the plunger assembly after the pointed tabs have been bent into positions substantially parallel to the main body portions of the clips.

Figure 14 is a view in end elevation of the clip shown in Figures 5 and 6.

The clip The clip which is intended to be driven by the machine of this invention is illustrated and described in detail in the said copending application above identified. One of these clips is shown individually in Figures 5 and 6 and is referred to in its entirety by the reference character C. Each clip C comprises a main body portion iii of substantially rectangular formation that is formed from an appropriate sheet metal. At each comer of the main body portion ill is a downwardly directed pointed tab II that is formed by severing the necks which join each clip C to the next adjacent clip in the magazine strip. Between the pointed tabs H at each end of each clip there is a recess l2 which is left when the joining necks are severed.

1 integrally joined to the main body portion III at each end thereof is a leg L that is defined by a pair of spaced struts l3. integrally joined to the lower end of each pair of these struts I3 is a concavo-convex pointed tab l4 that is slightly inclined with respect to the leg L. The inclination is such that the upper edge of each tab I4 is positioned immediately beneath the respective recess l2.

Upon referringto Figure 1 it will be noted that a plurality of these clips C are joined into a continuous magazine or strip that is designated B by depressed necks at l6. When these necks 16 are severed, they leave the pointed tabs II. It is further noted that the strip S may be coiled into a compact formation in the manner disclosed in said copending application with the coil beingreceived in a magazine that will be conveniently located with respect to the machine of this invention.

General assembly The casing The casing comprises two complemental halves A and B which are substantial duplicates. Each 'of these parts A and B includes a flat bottom or base It that is adapted to rest on the material inth which the clips are to be driven. Thus, if the flaps of a carton are to be joined, the bases l6 of the casing halves A and B rest on the top of the carton flaps Each base l6 has an outer edge at H to which is integra'ly joined an upwardly extending outwardly inclined flange l8.

This flange extends along the entire outer edge i1 and is notched as indicated at I! for indicating purposes. Each base |6 also has an end 'edge at 26 from which upstands a flange 2| that is Joined to the flange |8 by a bend 22. At the opposite end 23 there is another end flange 24 which is-joined to the flange H by a bend 26.

The inner edge opposite to the edge I1 is of a somewhat irregular formation and upstanding therefrom are various casing wall sections. Thus, a casing wall 26 upstands from this edge and extends inwardly from the end edge an appreciable distance. It is then joined to a transverse casing wall section 21 with another casing wall section 28 being integrally joined to the latter. At the end of the wall section 28 remote from the section 21 is another transverse section being disposed opposite to one another. Thus. the casing wall sections 26 define a slot or narrow channel which houses the feeding mechanism. The section walls 21, 28, 28, 38, and 3| enclose the plunger assembly.

The casing halves A and B are maintained assembled by the screw bolts at 33 which clamp the flanges 32 together, also by a bolt and sleeve assembly that is shown in Figure 'I and which comprises a bolt 34 having a head 36 on one end and a nut 36 on the other. This bolt passes through aligned openings 31 formed in the wall sections 26 with a spacer sleeve 38 being interposed between the wall sections 26 to maintain the latter in properly spaced relation. Each base l6 may carry a supporting rib indicated at 38 that is located opposite to the notch l9 and which has flanges 48 that are secured to the casing wall section 38.

Feeding mechanism The feeding mechanism includes a track designated T and which comprises itlat bands or strips of metal 4| which are spaced apart. This track T has a vertical component such as shown in Figures 1, 3, and 4 which extends to the magazine (not illustrated) that houses the strip 8. The track includes a horizontal component that is anchored to the inner faces of the casing wall sections 26 and which is joined to the vertical component by the bend indicated at 42. Asia clearly shown in Figures '7 and 8. each stnp 4| of the horizontal component of the track T is secured to the inner race of the casing wall section 26 by screws shown at 43.

Referring now to Figures 3, 4, and 8, it will be noted that a guide member 44 is also secured to the inner face or each casing wail section 26 above and in spaced relation with respect to the horizontal component of each track band 4|, thus providing spaces at 46 for receiving the side edges 01 the main body portion Ill 01 each clip C. It will be noted from Figures 2 and 4 that the legs L and pointed tabs carried thereby are disposed between the bands 4| of the track T. The outer end of each guide 44 is inclined as shown at 46 in Figures 3 and 4 to provide flared mouths which iacilitate entry of the side edges of the main body portion Ill into the slots 46.

Rotataoly mounted on the sleeve 38 is a feed wheel 41. The feed wheel 41 comprises a hub 48 which receives the sleeve 38 and to which is iniegrally joined a fiat plate of substantially hexagonal formation making up the main body portion of the feed wheel 41. The latter also includes an outer peripheral flange 48 that is formed in sections, with each section defined by one side of the hexagon. Each end of each section 49 carries an outturned flange 68. These flanges 68 at the opposite ends of each section 48 are adapted to be received in the openings formed in the clips C by striking out the legs L and pointed tabs l4. These openings are designated 6| and have a flat end edge at 62 which are engaged by the projections 68. This establishes the driving relation between the feed wheel 41 and the strip S which is clearly illustrated in Figure 4.

A bell crank is referred to in its entirety by the reference character X. This bell crank comprises two angle members 63 and 64 which are rotatably mounted on the sleeve 38 on opposite sides of the hub 48 of the feed wheel 41. Each of the angle members 63 and 64 inciudes a long arm 66 and a short arm 66. At their outer extremities the long arms 66 are bridged by a cross piece 51 which is preferably formed integrally therewith. Extending between the short arm 56 adjacent to their free ends is a cross bolt 58 which is adapted to be engaged by an abutment member for actuating the bell crank as will be later described.

As is more clearly shown in Figures 3 and '1 a cross pin 59 is carried by the long arms 55 of the bell crank X immediately beneath the cross piece 61. This cross pin projects beyond the arms 55 at each side thereof and also beyond the strips 4| of the track T. A pair of tension coiled springs 60 are arranged with one end of each spring anchored to a projecting end of the cross pin 69. The other end of each spring is anchored to a strip 4| of the track T as shown at 61 in Figure 1. These coil springs 60 are adapted to be placed under tension by rotation of the bell crank X in a clockwise direction (speaking with reference to the showing of Figures 1, 3, and 4) and will in turn rotate the bell crank X in a counterclockwise direction when released.

A pawl 62 has a curled end 63 that is pivotally mounted on the cross pin 59 between the long arms 55 of the bell crank X and a free end at 64 which is adapted to engage the inner face of any of the projections 50 at the left-hand ends (speaking with reference to the showing of Fi ures 1, 3, and 4) of the flange sections 49. The main body portion of the pawl 62 has struck therefrom a tongue 65 which is longer than the gap between the projections 50 of adjacent flange sections 49. This tongue 50 prevents the point 64 of the pawl from coming into effective engagement with the outer face of a projection 50 at the right-hand end of the flange sections 49.

The tongue 65 has a turned up end 66 which is engaged by one end of a leaf spring 61. This leaf spring 61 passes around the curled end 63 of the pawl 62 and its outer free end abuts the cross piece 61 as indicated at 68. The leaf spring 61 exerts a tendency normally urging the point 64 of the pawl inwardly so that it will engage the inner faces of the projections 50 at the lefthand end of the flange sections 49.

Extending between the casing-wall sections 25 is a bolt 69 which is clearly shown in Figures 3 and 8. Spanning the space between the guides 44 immediately below the bolt 69 and slightly to one side thereof is a crossbar which is preferably formed by being struck from one of the guides 44. A leaf spring member 1| has a hub portion 12 that is coiled about the bolt 69. The leaf spring member 1| carries a tongue 13 which extends over the hub portion 12 and has an outturned end flange 14 that is in locked engagement with the crossbar 10. Thus, the crossbar 16 functions as an anchorage for the tongue 13 of the spring member 1 I.

Immediately above the hub portion 12, the leaf spring member 1| carries a pair of spaced projections which are preferably formed by being struck from the spring member 1|. These projections 15 are adapted to receive therebetween one of the projections '56 on the flange sections 49 to hold the feed wheel 41 against rotation. It is to be noted that the inherent tendency of the spring H is to move these projections 15 in a counterclockwise direction (speaking with reference to the Showing of Figures 3 and 4) and thereby cause the projections 15 to become engaged about one of the projections 50 as shown in Figure 4.

The outer free end of the leaf spring member 1| is formed with a crosshead 16, the inner edges of which are adapted to be engaged by abutment plates 11 that are included as a part of the plunger assembly. The lower edges of the abutment plates 11 are also adapted to engage the crossbolt 58 of the bell crank X upon downward movement of the plunger assembly.

Extending between the casing wall sections is a bolt 18. Also extending inwardly from each section wall 30 is a tab 19 which may be struck from the metal of the casing wall sections. An angular retaining device for the free end of the clip C at the end of the strip S is designated 66. The device 80 is pivotally mounted on the bolt 18. At each side thereof there are vertical arms 6| terminating in feet 82 which flt beneath the free end of the clip C. The retaining device 80 also includes a cam member 83 that is adapted to be engaged by the plunger assembly on the downward stroke to move the retaining device 80 from its position holding the clip.

A leaf spring 84 normally urges the retaining device in a clockwise direction (Speaking with reference to the showing of Figure 3) so that the vertical legs 8| bear against the projections 19 with the latter functioning as stops, limiting movement of the retaining device in this direction. These projections 19 also function as stops which are engaged by the free end of the clip as the latter is moved into position.

Briefly summarizing the operation of the feeding mechanism, it will be noted that on a downward stroke of the plunger assembly P, the abutment plates 11 move downwardly. This downward movement of the abutment plates 11 does two things. The upper edges of the plate move away from the under edges of the crosshead 16 of the spring 1| and thereby release this spring so that the projections 15 lock onto one of the projections 50 of the feed wheel 41. Thus, the latter is positively held against rotation.

Due to the engagement of the lower edges of the plates 11 with the cross bolt 58 0f the bell crank X, the latter is rotated in a clockwise direction. During this operation the point 64 of the pawl 62 rides over the first projection 50 at the right-hand end of one of the flange sections 49 and then over the projection 50 at the left hand end of the next adjacent section 49. The presence of the tongue 65 prevents the pawl from being brought down into effective engagement with the projection 56 at the right-hand end of the flange section 49. The stroke of the plunger assembly coupled with the length of the short arms 56 of the bell crank X is sufficient to move the bell crank through an angular distance of about 66 This indexes the pawl from the position shown in Figure 3 to that shown in Figure 4, and the springs 60 are placed under tension. Inasmuch as the bell crank X can move in a counterclockwise direction only when accompanied by movement of the feed wheel 41, and due to the latter being locked by the spring 1|, the feed wheel and bell crank remain in the position shown in Figure 4 until upon an upward stroke of the plunger assembly P the abutment plates 11 engage the crosshead 16 of the spring member 1| and break the interlock with the feed wheel 41. The latter is now free to rotate under the influence of the springs 66 which are rendered effective through the bell crank X and pawl 62. This rotation continues until the cross bolt 56 engages the lower edges of the plates 11. At the same time the free end of the clip C at the end of the strip S will engage the stop 19 and thereby be accurately positioned with respect to the plunger assembly P.

Plunger assembly The plunger assembly P includes a main block 85 having a main body portion of rectangular i'ormation which is slidably received between the casing wall sections 21, 28, and 29. and a tongue 88 at one end which extends over into the space between the casing wall sections 30. This block 85 is intended to be reciprocated between these casing wall sections, and in order to limit upward movement thereof a cap member 81 is secured to the casing wall sections 28 such as by depending flanges 88 which are secured in positions on the casing wall sections 28 by the screws .89. The cap member 8,! is formed with an opening 90 through which passes an operating plunger 9| that is screwed into a socket 92 formed in the block 85.

At this point it is well to note that the plunger assembly P may be actuated by any motive force desired. In the form of the invention illustrated in the drawing, the plunger 9| is shown as carrying a knob 9 at its upper free end which adapts it for manual operation. This particular means of operating the plunger assembly is purely illustrative and the invention contemplates the use of such devices as air motors, electric actuating instrumentalities, and mechanical devices which ail'ord increased mechanical advantage on the plunger 9|.

An expansion coil spring shown at 93 is disposed about the plunger 9I and has its lower end in engagement with a spring retainer 94 carried by the cap 81 and its upper end in engagement with a spring retainer 95 carried by the lower face of the knob 9. The normal tendency of the spring 93 is to maintain the plunger assembly in an upraised position with the block 85 engaging the lower face of the cap BI.

Angle member 96 is secured to the block 85 by screw bolts 91 and 98, and the abutment plates 'II are carried by this angle member 96.

The block 85 has a lower face designated 99. Extending into this block from this face 99, at opposite ends thereof and substantially centrally of the block. are a pair of sockets I and I 0|. Received in the socket I 00 is the shank of a bending tool I02, while received in the socket IOI is the shank of a similar bending tool I08. The bending tools I02 and I03 may be secured in their respective sockets by set screws having points that are received in recesses formed in the shanks of thetools. The lower end of the bending tools I02 and I03 is indicated at I04, and it is these ends I04 which are adapted to engage the upper edges of the pointed tabs I4, as will be later described. to bend these tabs. The inner ide of each bending tool I02 and I03 is formed with a fiat face 8 which terminates in a shoulder I for a purpose to be later described.

The block 85 is also formed with a vertical bore I05 which terminates in a counterbore I06.

A guide bolt W1 is received in the bore I05 and has a head I08 received in the counterbore I06.

- The lower end of the guide bolt I0I is threaded I as indicated at I09. It is to be noted that the block 85 is slidable with respect to the guide bolt The underface 99 of the block 85 is cut away at one edge, and between the extremities of the block to provide a recess at IIO (see Figure 10) for a purpose to be later described.

An auxiliary block III is of rectangular formawith the lower face tion and is slidably positioned between the easing wall sections 28. This auxiliary block III is formed with a recess 6 at each end with each recess slidably reeciving one of the bending tools I02 and I08. The upper face of this block which is designated I I2 is formed with a threaded socket H8 into which is screwed the threaded end I09 of the guide bolt I01. Thus, the lower end of the guide bolt is anchored to the auxiliary block III.

Extending into the auxiliary block I I I from the top face H2 is a transverse slot II4. Extending between the side faces of the slot H4 is a pivot pin II5 which has its opposite end portions received in aligned bores formed in the auxiliary block III on opposite sides of the slot I I4. Rotatably mounted on this pivot pin I I5 is a bell crank II8 having a horizontal arm I" and a vertical arm H8. The upper free end of the vertical arm IIO normally engages the underface 99 of the block 85 at one side of the recess I I0.

The horizontal arm I ll extends through a slot II9 formed in one of the casing wall sections 28 (see Figure 1) and exteriorly of the casing carries an abutment pin I20, the lower end of which is adapted to strike the base of the casing on downward movement of the plunger assembly and thereby rotate the bell crank I It on the pivot pin H5 and thus bring the vertical arm II8 into alignment with the recess II 0 and thereby provide for relative movement between the block 85 and the auxiliary block III.

The auxiliary block III has a lower face I2I from which extend four pointed supporting tools I 22. There is a supporting tool I22 for each strut I3 of each leg L of the clips C. Each of the supporting tools I22 has a flat back at I23 which is adapted to assume a face-to-face engagement with the face of the strut I8 which it is intended to support.

The supporting tools I22 may be secured to the auxiliary block III in any preferred manner. As shown in the drawing, each of these supporting tools I22 has a head I24 that is received in a recess formed In the face I2I. A cutter plate I25 is formed with four openings I28 through which the supporting tools I22 extend. This cutter plate is clamped into face-to-face engagement I2I of the auxiliary block III by a pair of screw bolts I2'I. Each end of the cutter plate I25 is formed with a recess 5 having an inner flat edge 4 over which the flat faces 8 of the bending tools I02 and I03 are adapted to slide. This sliding movement is limited by the shoulder 1. It will be noted that these screw bolts I2I are positioned by being inserted through the slot I I4.

The cutter plate I25 projects beyond the auxiliary block III at each end thereof and on both its upper and lower faces at each end and on each side is formed with a shear I28. Each shear I28 is intended to sever one of the necks I5. The cutter plate I25 is formed with eight of these shears, although only two are used at any one time. The

' reason for this is that after continued use, the

shears become dull and new shears may be brought into effective position by changing the position of the cutter plate I25 relative to the eral elements of the plunger assembly P, it is noted that as downward movement begins the block 85. auxiliary block II I, and cutter plate I25 move together. The first action is a shearing of the necks I which join the clips C at the free end of the strip S to the strip. While this is taking place. the supporting tools I22 move down through the openings 5| so that fiat backs I23 come into engagement with the inner faces of the struts I3. After the necks I5 are sheared, the clip is free and is now moved downwardly so that the le s L and pointed tabs I 4 pierce the material. This act on is continued until the main body portion III en a es the upper face of the material being securely clamped thereagainst by the lower face of the cutter plate I25.

At this point the abutment pin I enga es the face I! and thereby rocks the bell crank I I6 so as to move the vertical arm II8 over into the recess IIO. This permits further downward movement of the block 85 and the bending tools I02 and I03. These tools slide downwardly through the recesses 8 in the auxiliar block II I and recesses 5 in the cutter plate I and enga e the up er edges of the pointed tabs I to bend the latter about the lower edges of the supporting too s I22 as fulcrums and into a po it on substantially parallel to the main body portion of the clip.

Operation While the operation of the feeding' mechanism and the plunger assemblv has been br efly summarized. it is deem d advisable to describe a complete cycle of operation of the entire machine.

Unon referring to Fi ure 11 it will be noted that a clip C has been moved into position directlv beneath the plunger assemblv P. In this position the pointed tabs II at the free end of the clip rest on and are supported by the feet 32 of the retaining device 80. Moreover, the foremost edge portions of the cli as defined by the tabs II, engage the stops I9. Thus. the clip C is accu rately positioned and in this position the ne ks I! which join this clip C at the free end to the strip 8 is positioned over the beveled edges of the shears I29.

The operator now presses downwardly on the knob 9 to move the plunger assembly P downwardly. The first act on which t kes lace is the entry of the supporting tools I22 into the reces es 5| so that the flat backs I 23 of these su porting tools assume a face-to-face enga ement with th inner faces of the struts I3. At that point where the lower face of the cutter plate I25 engages the up er face of the main bodv portion ll of the clip C. the shear elements I 28 which are in effective position will be fitted in the depressions of the depressed necks I5.

Continued down ard movement cau es the shears I28 and I29 to cooperat so as to shear the necks I5 and free the clip C at the end of the strip from the strip. It is notable that during this shearin action. the free en of the clip C is supported in a horizontal position by the retaining device 80.

The pieces of material to be jo ned are indicated by broken lines in Fi ures ll. 12, and 13 and are identified as Y and Z. Purely by way of example it may be assumed that members Y and Z are the fiaps of a carton which are to be joined by the clip C.

As the plunger assembly moves downwardly, the blocks 85 and auxiliary block III move together because the vertical leg II! of the bell crank H6 is in a position transmitting the thrust from the block I! to the auxiliary block III. As

this downward movement is continued, the less L, the struts of which are now supported by the supporting tools I22 and the pointed tabs, pierce the material Y and Z. This piercing action continues until the underface of the main body portion In of the clip C engages the upper face of the material Y and Z. As this takes place the downwardly pointed tabs II will be driven into the upper faces of the material Y and Z so as to become embedded therein and present a smooth surface. At the same time the abutment pin I20 engages the base I5 of the casing. This rocks the bell crank II6 about the pivot pin II! and moves the vertical arm IIB over into the recess I I0 so as to permit further downward movement of the block while the auxiliary block II I and cutter plate I25 are held immovable.

The position of the clip and the relative position of the blocks 85 and III, after the driving of the legs, is depicted in Figure 12. As the block 85 moves downwardly, the bending tools I02 and I03, which extend through recesses 6 formed in the ends of the auxiliary block III and recesses 5 in the cutter plate I25, pass through recesses I2 in the clip C and engage the upper edges of the pointed tabs ll. As the downward movement is continued, these pointed tabs are bent about the lower pointed ends of the supporting tools I22 as a fulcrum and into the horizontal position in which they are substantially parallel to the main body portion III. This position is illustrated in Figure 13.

As the plunger assembly first moves downwardly the plates 11 release the spring II so that the latter interlocks with the feed wheel 41 to hold the feed wheel against rotation. The lower edges of the plates I1 engage the cross bolt 5! of the bell crank X so as to rotate the bell crank and tension the spring 60. As this takes place the pawl 62 rides over the projections 50.

When the operator releases the plunger 9|, the spring moves the plunger assembly upwardly. At the completion of this upward stroke, the plates 'I'I engage the crosshead 16 of the spring II to break the interlock between the spring II and the feed wheel 41 and thereby permits the feed wheel to be rotated under the influence of the tension of springs 60 which is transmitted to the feed wheel 41 through the bell crank X and pawl 62. This indexes the clip at the free end of the strip S into the position shown in Figure 11 whereupon the machine is ready for another cycle of operation.

While a preferred specific embodiment of the invention is hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions, mechanisms and devices illustrated and described, because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

What is claimed is:

1. In a machine for driving a clip having a fiat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: driving means adapted to engage said clip to force said legs and the pointed tabs carried thereby into pieces of material to be joined, leg supporting tools adapted to engage the inner faces of said legs as they are driven by said driving means, and means operable from the side of the clip from which said driving means is eil'ective and in the same direction as said driving means, for bending said pointed tabs about the free ends of said supporting tools into positions substantially parallel to said body portion.

2. In a machine for driving a clip having a flat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: driving means adapted to engage said body portion to exert a force on said clip substantially in the direction of said legs to cause said legs and the pointed tabs carried thereby to pierce pieces of material to be joined, supporting tools operable through said driving means and engaging said legs during said piercing operation, and-a pair of bending tools operable from the same direction as said driving means and said supporting means and adapted to engage said pointed tabs to bend them about the free ends of said tools into a position substantially parallel to said body portion.

3. In a machine for driving a clip having a fiat main body portion. a pair of legs normal to said bodv portion. and po nted tabs integrally joined to the free ends of said legs, the combination of: driving means adapted to engage said body portion to exert a force on said clip substantially in the direction of said legs to cause said legs and the pointed tabs carried thereby to pierce pieces of material to be joined, supporting means engaging said legs during said piercing operation, and a pair of bending tools adapted to engage said pointed tabs to bend said pointed tabs about said supporting means as a fulcrum into positions substantially parallel to said body portion.

' 4. In a machine for driving a clip having a fiat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: feeding mechanism for moving said clip into position for driving, and a plunger assembly including means for engaging the body portion of said clip to drive said legs and tabs carried thereby into pieces of material to be joined, leg supporting tools operable through said body portion engaging means, and bending tools for bending said tabs about the free ends of said tools into position substantially parallel to said body portion.

5. In a machine for driving a clip having a flat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: feeding mechanism for moving said clip into position to be driven, a plunger assembly including a main block and auxiliary block which are relatively movable with respect to one another, means carried by one of said blocks for engaging the body portion of said clip to exert a. force thereon in the direction of said legs to cause said legs and pointed tabs to pierce pieces of material to be joined, leg supporting tools carried by said main block, and bending tools carried by the other of said blocks and operable as an incident to relative movement of said blocks to bend said tabs into positions substantially parallel to said body portion.

6. In a machine for driving a clip having a flat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: feeding mechanism for moving said clip into position to be driven, a plunger assembly including a main block and auxiliary block which are relatively movable with respect to one another, means carried by said auxiliary block for engaging said clip to drive said legs and tabs carried thereby into pieces of material to be 14 joined, leg supporting tools carried by said main block, and bending tools carried by said'main block and operable as an incident to relative movement between said blocks to bend said tabs into positions parallel for said body portion.

7. In a machine for driving clip having a flat main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: feeding mechanism for moving said clip into position to be driven, a plunger assembly including a main block and an auxiliary block which are relatively movable with respect to one another, means carried by one of said blocks for engaging the body portion of said clip to exert a force thereon in the direction of said legs to cause said legs and pointed tabs to pierce pieces of material to be joined, leg supporting tools carried by said main block, bending tools carried by the other of said blocks and operable as an incident to relative movement of said blocks to bend said tabs about the ends of said supporting tools into positions substantially parallel to said body portion, and actuating means for moving the said plunger assembly as a unit and for causing relative movement between said blocks.

8. In a clip-driving machine adapted for operation on a strip of clips, each of which is integrally joined to the next adjacent clip and has a main body portion, a pair of legs normal to said body portion, and pointed tabs integrally joined to the free ends of said legs, the combination of: severing means for separating the clip at the free end of said strip from the strip, driving means adapted to engage the main body portion of the clip to drive said legs and pointed tabs carried thereby into pieces of material to be joined, leg supporting tools carried by said main block, and bending tools operable in the same direction as said severing means and driving means for bending said pointed tabs about the ends of said supporting tools into positions substantially parallel to said body portion.

9. In a clip-driving machine intended for operation on a strip of clips integrally joined, each of which has a flat body portion, a pair of legs normal to said body portion and pointed tabs carried at the free ends of said legs, feeding mechanism comprising a track over which said strip is adapted to travel, a feed wheel adapted to interlock with said strip to cause movement thereof: a bell crank coaxially mounted with respect to said feed wheel, a pawl carried by said bell crank and engaging said feed wheel to establish a driving relation between said wheel and bell crank in one direction of rotation, spring means associated with said bell crank and adapted to be tensioned upon movement of said bell crank independently of said wheel, means to so actuate said bell crank to tension said spring means, and locking means for holding said feed wheel immovable as said bell crank is tensioned.

10. In a clip-driving machine of the character described, the combination of: feeding mechanism adapted for operation on a strip of integrally joined clips, a retaining device for supporting the free end of the clip at the end of said strip, a stop number on said supporting device and adapted to be engaged by said free end to accurately position the clip at the end of said strip, and a cam associated with said retaining device for moving said device out of supporting position while said clip is driven.

11. In a clip-driving machine of the character ataae'ra described, a casing having spaced wall sections, a plunger assembly mounted for reciprocation between said wall sections, said plunger assembly comprising a main block, a pair of bending tools carried by said main block, an auxiliary block movable relative to said main block and having recesses through which said tools pass, and supports carried by said auxiliary block and adapted to engage struts on a clip being driven by the machine.

12. In a clip-driving machine of the character described, a casing having spaced wall sections, a plunger assembly mounted for reciprocation between said wall sections, said plunger assembly comprising a main block, a pair of bending tools carried by said main block, an auxiliary block movable relative to said main block, and having recesses through which said tools pass, a cutter plate carried by said auxiliary block, and leg supports carried by said auxiliary block, and

passing through openings in said cutter plate.

13. In a clip-driving machine of the character described, feeding mechanism including a feed wheel, a bell crank associated therewith, and spring means for actuating said feed wheel and adapted to be tensioned by movement of said bell crank independently of said feed wheel, a plunger assembly, and an abutment plate carried by said plunger assembly and adapted to engage said bell crank to tension said spring means.

14. In a clip-driving machine of the character described, feeding mechanism including a feed wheel adapted for interlocking engaging with a strip of clips, a spring also adapted to become interlocked with said wheel to hold said wheel against rotation, a bell crank movable independently of said wheel in one direction, a pawl for establishing a driving relation between said bell crank and wheel for movement in the opposite direction, springs adapted to be tensioned by movement of said bell crank independently of said wheel, a plunger assembly, an abutment plate carried by said plunger assembly and adapted to engage said bell crank to tension the last mentioned spring means, and also adapted for engagement with the first mentioned spring to break the interlock between said spring and said wheel.

15. In a clip-driving machine of the character described, feed mechanism for moving a strip of clips with a step by step motion to index the strip at the free end of the strip into position for driving, spring means for actuating said feed mechanism, a plunger assembly for separating said clip from the free end of the strip therefrom and driving said clip, and means carried by said plunger assembly for tensioning said spring means.

16. In a clip-driving machine, a casing having spaced wall sections and a base, a plunger assembly mounted for reciprocation between said wall sections and comprising a main block, an auxiliary block, a bell crank having a vertical arm normally maintaining said blocks in spaced relation, a horizontal arm extending through a slot in said wall sections, and an abutment pin carried by said horizontal arm and adapted to engage said base to move said vertical arm to permit relative movement between said blocks.

17. In a machine for driving a clip having a substantially rectangular body portion with a downwardly directed pointed tab at each corner thereof, a leg at each end normal to said body portion, and a pointed tab integrally joined to the free end of each leg, the combination of a cutter plate having shear elements at each corner thereof and conforming in curvature to said pointed tabs at the corners of said main body portion and with which they are adapted to engage, means for moving said cutter plate in the direction of said legs to cause said legs and the tabs carried thereby to pierce material, and tools for bending said pointed tabs at the free ends of said legs after piercing said material.

18. In a clip-driving machine adapted to operate on a strip of clips with each clip being Joined to the next adjacent clips by a pair of laterally spaced depressed necks and each clip having a main body portion, a leg at each end thereof normal to said body portion, and a pointed tab integrally Joined to the end of each leg, the combination of: a pair of fixed shear elements adapted to engage the underside of said strip at a pair of said depressed necks, a cutter plate having a pair of shear elements adapted to engage the upper side of said pair of depressed necks and to cooperate with said fixed shear elements to sever said necks, means for driving said cutter plate to cause said legs and pointed tabs carried thereby to pierce material, and tools for bending said tabs after piercing of said material.

19. In a clip-driving machine adapted to operate on a strip of clips with each clip being Joined to the next adjacent clips by a pair of laterally spaced depressed necks and each clip having a main body portion, a leg at each end thereof normal to said body portion, and a pointed tab integrally joined to the end of each leg, the combination of: a pair or fixed shear elements adapted to engage the underside of said strip at a pair 01' said depressed necks, a cutter plate having a pair of shear elements at each corner thereof, with each shear element having a contour corresponding to said depressed necks, the shear elements at one end of said cutter pate being adapted to cooperate with said fixed shear elements to sever a pair of said necks and thereby leave a downwardly directed pointed tab at each corner of said body portion, each of said downwardly set of pointed tabs being adapted to be engaged and backed by a shear element on said cutter plate, means for moving said cutter plate in the direction of said legs whereby said legs and pointed tabs carried thereby are driven into pieces of material to be joined while the pointed tabs at each corner of said body portion are embedded in said material, and tools for bending said pointed tabs at the free end of said legs into positions parallel to said body portion.

WERNER SCHAFROTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Num er Name Date 572,293 Greenfield Dec. 1, 1896 1,581,288 Polzer Apr. 20, 1926 1,796,572 Matveyefi Mar. 17, 1931 1,878,417 Matveyefl Sept. 20, 1932 2,012,027 Taylor et a1 Aug. 20, 1932 2,296,493 Bernstein Sept. 22, 1942 2,308,611 La Place Jan. 19, 1943 2,314,184 Zeruneith Mar. 16, 1943

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