US2968913A - Chain-link forming apparatus with blank-feeding means - Google Patents

Description

Jan. 24, 1961 w. ONULAK 2,968,913

CHAINLINK FORMING APPARATUS WITH BLANK-FEEDING MEANS Filed May 27, 1957 3 Sheets-Sheet 1 s-r FORM 16 OFFSET POSITmNIN B ow a" ram 2 FORM MAG.

'9 fl j 1P" 5 l INVENTOR a. Eugene (.U.Qnu|a.k.\

Aew'h ATTORNEYS E. w. ONULAK 2,968,913 CHAIN-LINK FORMING APPARATUS WITH BLANK-FEEDING MEANS 3 sheets sheet 2 Filed May 27, 1957 lll ATTORNEY5 Jan. 24, 1961 w. ONULAK CHAIN-LINK FORMING APPARATUS WITH BLANK-FEEDING MEANS Filed May 27, 1957 3 Sheets-Sheet 3 MWsfiM ATTO R N EYS INVENTOR E gene ULOnu aK CHAIN-LINK FORMING APPARATUS WITH BLANK-FEEDING MEANS Eugene W. Onulak, Trumbull, Cnn., assignor to The Locke Steel Chain Company, Bridgeport, Conn., a corporation of Connecticut Filed May 27, 1957, Ser. No. 661,648:

3 Claims. (Cl. 59-6) This invention relates to apparatus for forming drive and sprocket chains, and particularly to apparatus for forming a sheet metal chain link.

Relatively inexpensive chains suitable for many types of transmissions and conveying purposes are in demand. Frequently, chains will be.used under difiicult running conditions where maintenance must be reduced and also will be used under outdoor conditions where abrasion factors become a problem, including those caused by the weather. These chains must have suiiicient strength and wearing properties for the purpose and yet must be easily fabricated. It is desirable that the bushings of the chain links be formed from an integral tab on a singlesheet metal blank in a continuous operation.

One of the primary objects of the present invention is to provide apparatus for forming the bushing of a chain link from a tab extending outwardly from a fiat blank.

Another object of the invention is to provide apparatus for economically forming the cylindrical bushings of chain links of the type disclosed in my copending application Serial No. 426,393, filed April 29, 1954, now Patent No. 2,793,536.

A still further object of this invention is to provide an apparatus in which the various operations required to form the cylindrical bushing and the offset legs of an integral chain link from a flat sheet metal blank are performed sequentially in a single machine having a plurality of operating stations.

The apparatus according to the invention forms the bushing of an integral chain link from a flat blank having a tab extending outwardly from one of the sides of the central portion of the blank. The apparatus includes means for depressing the central portion of the blank relative to the remainder of the blank and means for curling the tab so that the free end of the tab is adjacent the other side of the central portion. A bushing is thereby formed which is comprised of the tab and the depressed central portion. In one aspect of the invention each operation is carried out at a separate station and the flat blank is sequentially advanced by feeding means, step-by-step, from station to station.

Other objects, advantages and features of the invention will become apparent from the following description and drawings, which are merely exemplary.

In the drawings:

Fig. 1 is a schematic view of the apparatus provided according to the invention;

Fig. 2 is a perspective view of the link after it has been acted upon by the apparatus of the invention;

Fig. 3 is a diagrammatic view showing the operations performed at the various stations;

Fig. 4 is a plan view of the apparatus showing the feeding means thereof;

Fig. 5 is a cross-sectional view taken along the lines 5-5 of Fig. 4, looking in the direction of the arrows;

Fig. 6 is a view similar to Fig. 5 showing the parts when the reciprocating feed means is moving in its nonfecd direction; and

Fig. 7 is a cross-sectional view of one of the operating stations.

As can best be seen in Fig. 3, each flat blank must undergo a plurality of operations so as to form the partially completed link 14, shown in Fig. 2.

Reciprocating feed means, shown generally as 10 in Fig. 1, advances each blank B through all of the stations where the various operations take place. The feed is of a step-by-step type so that each blank can be acted upon at each of the stations, as will be described more specifically hereinafter.

A vertically reciprocating head 11 carries a number of tool or forming punches 12, diagrammatically shown in Fig. 1 one for each operation to be performed. Because of this construction each die acts on one blank with each downward movement of head 11. The operation of head 11 and feeding means 10 is timed, in any known manner, so that a blank Bis advanced from one station to the station nearest to it on its left, as seen in Figs. 1 and 3, remains there while head 11 moves downwardly and tool 12 under which it is positioned acts on it, and then is advanced further to the left when head 11 resumes its upper position, as shown in Fig. 1. After the blank has passed through all of the stations and is in the form shown in Fig. 2, it is advanced beyond the left-hand side of feeding means 10 where it is progressively moved to the left by other blanks pushed against it until it slides down chute 13. In order to prevent feed means 10 from regripping a completed blank, holding means for the blank (not shown) may be provided beyond the last operating station. The holding means may be of any desired type and does not form a part of this invention.

The link 14 shown in Fig. 2 is formed from an elongated sheet metal blank having a tab 15 extending from one side of the central portion 16 of the blank and a shorter tab 17 extending from the opposite side of said central portion. The original blank as well as the link shown in Fig. 2 are disclosed in my above-mentioned copending application. In order to complete the link of Fig. 2 so that a chain can be formed from a plurality of links, the legs of link 14 must be bent upwardly, as viewed in Fig. 2, about their juncture with the central portion of the blank, and appropriate holes must be punched in the legs. However, the apparatus of the herein described invention does not include means for performing these operations, and the completed link for the purposes of this application is the link shown in Fig. 2.

The operations which are performed at each of the various stations are illustrated diagrammatically in Fig. 3. As can be seen from Fig. 3 the distance between adjacent operating stations is the same in all cases.

The blank is first advanced from magazne 18 against a disappearing or vertically reciprocating stop 19 at the positioning station 20. This stop may be actuated in any known manner, as for exampe, hydrrulical'y, and its movement into and out of operative position is t'med to the operation of feeding means 10, in any desired manner. When a blank from the magazine is approaching the positioning station 20, the stop is in the operative position, shown in Fig. 3. When a blank is bing moved from station 20 to offset station 21, the stop is in an inoperative position below the path of travel of the blank. The operation of stop 19 thus guarante s that each feeding movement of feeding means 10 does not cover a linear distance more than the distance between adjacent operating stations.

The blank B is then advanced from station 20 to station 21 where the ends 26 of the legs 27 are offset relativeto the plane of legs 27 to the position shownsin Fig. 2. In this position offset ends 26 are parallelto and below legs 27 and are connected thereto by.a s'anted "ice portion 28. The purpose of these offset ends is clearly shown in the above-mentioned copending application, and permits the cylindrical bushing of one finished link to fit within the offset ends of another finished link after thelegs are properly bent'around their juncture'withthe bushing.

The blank B is next advanced to station 22 where the ends of tabs and 17 are turned or partially curled in an upward direction. This is the first step in the formation of the cylindrical bushing of the link.

At next station 23, central po-tion 16 of blank B is depressed below the plane of legs 27. The depresion is preferably a curved depression so that central portion 16 will form the bottom of the cylindrical bush'ng of the link. Upon depression of the central portion, tabs 15 and 17 will be forced upwardly and towards each other.

The tab 15 is bent further at station 24 by the die at this station so that it is in a nearly vertical positizn and is more easily acted upon by the curling die at station 25 which compfetes the formation of the bushing.

Blank B is next advanced to the curling die locafed at station 25 which curls tab 15 until its free end is adjacent the free end of tab 17. Thus a generally cylindrical bushing is formed by tab 15, tab 17, and the depressed central portion 16 of the link. If desired, tab 17 may be omitted and tab 15 curled around until its free end is adjacent the opposite side of central portion 16. If this is done, the operations at the various stations will be the same except at station 22 where tab 15 is the only part that will be partially curled.

The preferred form of feeding device is best shown in Figs. 4 and 6 and operates to grip all of the blanks and advance them a distance equal to the distance between two adjacent stations. The feeding device includes transversely spaced frame members 30 having horizontally disposed rollers 31 and vertically disposed rollers 32 which form a track upon which the reciprocating feeding member travels.

The feeding member includes an upper plate having spaced apart, longitudinally extending legs 33a connected together by front and back crosspieces 45 and 46, respectively. Vertically spaced from each of the legs 33a is a lower plate 34 which travels on a roller 31. Between each leg 33a and its corresponding plate 34 are spaced inner and outer bars 36 and 35, respectively, having recesses along their length for receiving springs 37, which urge said bars apart. Fixed to bar 36 are narrow plates 38 having tapered cutouts 39 therein. Plates 33 and 34 and bars 35 and 36 of the feeding member are connected together for simultaneous longitudinal movement.

The feeding member is reciprocated by a motor operated rod 40a, or other suitabe reciprocating means, connected to the front crosspiece of bar 33. As the feed ing member is moved to the left (as seen in Fig. 4), suitable pick-off means, or the like, removes the lower blank from the magazine and moves it to station 20. At the same time, each of the blanks still in the apparatus is advanced from the station it occupies to the next succeeding operating station. This advance is accomplished by the blank B being held in the cutouts in members 38 by the action of springs 37. The non-tapered edge of the cutouts contacts the rear, or right-hand, edge of the ends of the blank so that the blank is carried to the next station.

At each station the reciprocating die members depress the blank from its solid line position to the dotted line position, as shown in Fig. 7, into a depression 39a in the lower die member, so that all of the blanks B are held against longitudinal movement by the sides of this depression. Thus, as the feeding member moves rearwardly or to the right in Fig. 4, the ends of the b'a:.ks B held by the depression will force members 36 apart. The tapered portions of the cutouts will ride along the ends, making this separating movement gradual. During the rearward or non-feed movement of the feeding member, the bars 36 and the blanks will assume the positions shown in Fig. 6, causing springs 37 to be compressed. When the feeding member travels relative to frame 30, bar 34 travels on roller 31, bar 35 travels on roller 32, and bar 33a is held against upward movement by extension 40 on frame 30.

As seen in Fig. 7, the die members used at the various stations include a suitable lower die 41 and a suitable upper die 42. On either side of each of the dies are vertical holding rods 43, 43, respectively, which are spring-pressed away from the die member by suitable springs 44. The rods 43 adjacent the upper die ex end downwardly and the rods 43 on the lower die extend upwardly. Each set of rods 43 is vertically aligned with its corresponding set of rods 43. As the head 11 moves downwardly, the vertical holding rods 43 on the head, and the holding rods 43 in the lower die, will embrace the blank. Upon further downward movement of head 11 the blank will be depressed from its feed position and dies 41 and 42 will act upon it to complete the operation for a particular station. In order to depress the blank, the upper springs are made heavier than the lower springs, so that the lower springs will compress until the blank reaches the bottom of depression 39a before the upper springs compress. The die member structure at each of the stations 20-25 may be substantially the same and only the dies 41 and 42 need be dfierent to perform the different operations. It will be obvious that any suitab'e die structure could be used in place of that disclosed.

Due to the particular structure utilized in the preferred form of the invention, the feeding means can move in a rearward or non-feed direction while the dies at each of the stations are acting on the blanks B. In this condition, the feeding member can then move the blanks to the next station as soon as head 11 returns to its Fig. 1 position.

During each forward movement of the feeding mechanism a blank B is held in each of the corresponding pairs of transversely spaced cutouts 39 in plates 38 and moved to the next station, and a blank B is advanced from the magazine to station 20 by the pick-off means. During each rearward movement of the feeding mechanism, each of the blanks B is forced into a depression 39a by the corresponding upper rods 43 and held therein, thereby preventing its rearward movement. The ends of the blank act on the tapered portion of cutouts 39 and force plates 38 and bars 36 outwardly against the action of springs 37. This permits the feeding member to return into the proper position for another advancing operation. By utilizing the preferred apparatus each blank is acted upon, in sequence, by the die mechanisms at each of stations 21, 22, 23, 24 and 25, so as to form the link shown in Fig. 2. If desired, the number of stations may be increased or decreased, or the means at the stations may be varied to perform different operations.

It should be apparent that details of construction and form can be varied without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is:

1. In apparatus for forming integral chain links from fiat blanks, each of said blanks having a tab extending outwardly from one of the sides of the central portion thereof, the combination comprising a first station havmg press means for depressing said central portion relatlve to the blank, a second station having means for curling said tab so that its free end is adjacent the other side of the central portion of the blank, thereby forming a bushing comprised of the tab and the central portion, a Work surface for upwardly supporting said blanks, a depression in said work surface at each station extending below'the normal feed path of said blanks and having a rearward wall, movable upper and resilient lower holding means at each of said stations which engage and hold each of said blanks at points spaced from and on either side of said central portion and spaced inwardly 0f the free ends of said blanks prior to the engagement of each blank by the related operating means so that the blanks are preliminarily positioned and held in position at each station, and reciprocating feed means engaging only the free ends of said blanks for advancing said blanks over said work surface from said first station to said second station, so that the operating means at the stations act on different blanks simultaneously, said feed means comprising a pair of transversely spaced feed bars having blank end receiving indentations on their facing sides, said indentations having rearward surfaces adapted to normally abut the rearward surfaces of said blank ends and having forwardly sloping forward surfaces, said indentation surfaces extending below the feed path to the same extent as said rearward wall, means for depressing said upper holding means to depress said blanks into said depressions so that the bars are cammed apart by the ends of the blanks when the bars travel in a rearward direction, resilient means normally urging said bars toward each other and against the ends of the blanks, and means for reciprocating said feed bars over a predetermined linear distance, so that said bars move said blanks from the first station to the second station, said feed means moving in a non-feed direction at the time said operating means are acting on the blanks and said blanks are held in position by said resilient means.

2. In apparatus for forming an integral chain link from a flat blank having a tab extending outwardly from one of the sides of the central portion thereof, the combination comprising a first station having means for positioning the blank including a stop movable between operative and inoperative positions, a second station having means for bending the free end of the tab upwardly relative to the body of the tab, a third station having means for forming a curved depression in said central portion, a fourth station having means for partially bending said tab upwardly about its juncture with said central portion, a fifth station having means for curling said tab so that its free end is adjacent the other side of the central portion of the blank, thereby forming a bushing comprised of the curled tab and the curved depression in said central portion, a work surface for upwardly supporting said blanks, a depression in said work surface at each station extending below the normal feed path of said blanks and having a rearward wall, movable upper and resilient lower holding means at each of said stations which engage and hold each of said blanks at points spaced from and on either side of said central portions and spaced inwardly of the free ends of said blanks prior to the engagement of each blank by the related operating means so that the blanks are preliminarily positioned and held in position at each station, and reciprocating feed means engaging only the free ends of said blanks for advancing said blanks, step-bystep, over said work surface from said first station to the other stations sequentially, said feed means comprising a pair of transversely spaced feed bars having blank end receiving indentations on their facing sides, said indentations having rearward surfaces adapted to normally abut the rearward surfaces of said blank ends and having forwardly sloping forward surfaces, said indentation surfaces extending below the feed path to the same eittent as said rearward wall, means for depressing said upper holding means to depress said blanks into said depressions so that the bars are cammed apart by the ends of the blanks when the bars travel in a non-feeding direction, resilient means normally urging said bars toward each other and against the ends of the blanks, and means for reciprocating said feed bars over a pre- 6 determined linear distance which equals the space between adjacent stations, said feed means moving in a non-feed direction at the time said operating means are acting on the blanks said blanks are held in position by said resilient means.

3. In apparatus for forming an integral chain link from a flat blank having a pair of tabs extending in opposite directions from the sides of the central portion of the blank, one of said tabs being longer than the other, the combination comprising a magazine holding a plurality of blanks, a first station having means for positioning the blank including a stop movable between operative and inoperative positions, a second station having press means for offsetting the ends of said blank so that they are in a plane offset from and generally parallel to the plane of the blank, a third station having press means for bending the free ends of both of said tabs upwardly relative to the body of the tab, a fourth station having press means for forming a curved depression in said central portion, a fifth station having means for partially bending the long tab upwardly about its juncture with said central portion, a sixth station having press means for curling the long tab so that its free end is adjacent the bent free end of the short tab, thereby forming a cylindrical bushing comprised of said curled long tab, said bent short tab, and said curved depression, a single, vertically reciprocable head carrying said operating means for all of said stations, at work surface for upwardly supporting said blanks, a depression in said work surface at each station extending below the normal feed path of said blanks and having a rearward wall, movable upper and resilient lower holding means at each of said stations which engage and hold said blanks at points spaced from and on either side of said central portion and inwardly of said offset ends prior to the engagement of said blank by the related operating means so that the blanks are preliminarily positioned and held in position at each station, and horizontally reciprocable feed means for advancing said blanks, step-by-step, over said work surface from said magazine to all of said stations in sequence, said feed means including a pair of transversely spaced feed bars having blank end receiving indentations on their facing sides, said indentations having rearward surfaces adapted to normally abut the rearward surfaces of said blank ends and having forwardly sloping forward surfaces, said indentation surfaces extending below the feed path to the same extent as said rearward wall, means for depressing said upper holding means to depress said blanks into said depressions so that the bars are cammed apart by the ends of the blanks when the bars travel in a non-feeding direction, resilient means normally urging said bars toward each other and against the ends of the blanks and means for reciprocating said feed bars over a predetermined linear distance equal to the space between adjacent stations, said feed means moving in a nonfeed direction at the time said operating means are acting on the blanks and said blanks are held in position by said resilient means, said feed means engaging only the free ends of said blanks so that the central portion thereof may be acted upon by the press means and the resilient means at the several stations without interference from said feed means.

References Qited in the file of this patent UNITED STATES PATENTS 451,658 Egge May 5, 1891 1,810,716 Locke June 16, 1931 1,996,818 Marshall at al. Apr. 9, 1935 2,420,147 Norgren May 6, 1947 2,835,152 Lamprecht May 20, 1958

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