US2912094A - Plating apparatus - Google Patents

Description

Nov. .10, -1959 J. v. DAvls PLATING APPARATUS 4 Sheets-Sheet 1 Filed May 3, 1956 It! .INa

NOV. 10, 1959 J, v, DAVIS 2,912,094

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United Stai@ Patent O PLATING APPARATUS John V. Davis, Grosse Pointe, Mic-h., assignor to The Udylite Corporation, Detroit, Mich., a corporation of Delaware Application May 3, 1956, Serial No. 582,400 8 Claims. (Cl. 198-85) This invention relates generally to plating machines or the like. More particularly the invention relates to machines of the indicated character which are of the returntype wherein a plurality of work carriers are advanced Yaround a circuit usually having two straight-side sections connected on at least one 'of their ends by an arcuate turn-around section.

In plating machines, forpexample, of the above-mentioned return-type, a pusher-type transfer systemdis employed to move a plurality of work carriers around the circuit. The pushers may comprise a pusher bar or rod mounted along each straight-side section of the machine and a pair of radially-extending pusher arms rotatably 'mounted for oscillation substantially at the center of curvature of an arcuate turn-around section. In applicants prior U.S. Patent No. 2,650,600, of September 1, 1953, now reissue Patent No. 24,072, issued 'October 1l, 1955, there is disclosed such a machine wherein the shaft on which the radial pusher arms are mounted is arranged to be oscillated through an are of approximately 90 degrees by a fluid-operated piston and cylinder unit. The linkage therein utilized to connect Ithe shaft with the piston rod includes a link of a length approximating the length of either of the radial pusher arms. The operating cylinder is disposed adjacent to and longitudinally of one of the pusher bars inwardly of one of the arcuate ends. With this arrangement of linkages it is not practicably possible to oscillate the pusher arm shaft through an arc appreciably greater than 90 degrees as the piston rod and its connecting linkage would either approach aV dead center position or strike the pusher arm shaft. The greater the arc through which the pusher arm shaft oscillates, the greater is the linear travel and hence the spacing between successive workpieces as they move around the arcuate end.

The `trend of the plating art, with the advent of automatic loaders, is toward employing heavier and larger plating racks or work carriers which require even greater spacing in the arcuate end Las compared to the spacing thereof on the straight sides( of the machine, to avoid crowding of and contacting at these ends between successive work carriers. To obtain this great spacing, oscillation of the radial pusher arms through an are substantially greater than 90 degrees is required.

Moreover, with the linkage of the above-mentioned patent the two pusher bars on the straightsides of the machine are reciprocated through equal strokes. There are instances, however, when it is desirable to operate the two side pusher bars with different strokes.

Accordingly, it is an object of the invention to provide a return-type conveying apparatus applicable to plating machines so constructed and arranged that successive workpieces can be spaced a greater distance apart in the arcuate turn-around section.

Another object is to provide a machine of the type indicated having an arcuate turn-around section wherein a multiplier linkage is provided connecting a side pusher with a radial pusher arm in` the arcuate 1section so as `'to 2,912,094 Patented Nov. 10, 1959 rice impart a greater amplitude of oscillation to the pusher arm or arms whereby to effect a greater spacing of the Work carriers in their travel around the arcuatesection.

Another object is to provide a machine of the character described wherein the multiplier linkage is adjustable so that the spacing `of the work carriers in their travel around the arcuate section can be varied independently of their spacing as they move along the straight side sections.

Still another object is to provide a plating machine of the character described wherein the pusher bars on the sides of the machine may be operated with different strokes, a connection being effected between a radial pusher arm in the arcuate section and one of the side pusher bars and a second connection being effected through -a multiplier linkage between the other side pusher bar and the pusher arm shaft so as to impart a greater or lesser amplitude of oscillation there-to and thereby a differing stroke to the one side pusher bar.

Other objects and advantages of the invention will be apparent, or will Ibecome apparent in the following more detailed description of the invention take-n in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a side elevational view of the plating machine embodying the invention, the lowered position of the chassis being shown in outlines;

Fig. 2 is -a plan view of the structure of Fig. 1;

Fig. 3 is an enlarged fragmentary bottom view of certain parts of the structure of Fig. 1;

Figs. 4 and 5 are schematic views showing theoperation and adjustable features of the multiplier linkage;

Fig. 6 is a fragmentary sectional view substantially .on the line 6 6 of Fig. 3;

Fig. 7 is a fragmentary view of a modified form of construction for linking the actuating cylinder with one of the pusher bars on the straight side of the machine;

Figs. 8 and 9 are schematic views illustrative of the spacing of the work carriers in their travel around an arcuate end in apparatus of the prior art and the present invention respectively.

In accordance wlth the invention a conveying apparatus, such as a plating machine of the type having two straight side sections connected on at least one end by an arcuate section, is provided with a transfer pusher system comprising a reciprocally-operated pusher bar or other type of pusher member mounted along each of the straight sides and radially-extending pusher means, e.g., a pair of radial pusherl arms in the arcuate end. The pusher bar on one of the straight sides of the machine is connected to one of the radial pusher arms by a multiplier linkage so that the pusher element on the radial pusher arm may be actuated through an arcuate distance which is considerably greater than the corresponding distance traveled by the pusher bar itself. The two pusher bars on the straight sides of the machine can be linked to another set of radial pusher arms in the other arcuate end of the machine so that both pusher bars will have the same stroke. Alternatively, the two pusher bars can be linked to the pusher arms having the multiplier linkage so that one pusher will be actuated through a distance corresponding to the amplitude yof oscillation imparted to the pusher arms, thereby achieving different strokes on the two pusher bars. The multiplier linkage can be made adjustable so that the amplitude of oscillation imparted to the pusher arms can be varied independently of the stroke of the driven pusher bar member.

Referring now to the structure in more detail and specifically to Figs. 1 and 2, the machine comprises a central frame of upright columns 10, mounted on a base 11 surrounded by a system of tanks 12 comprising `reciprocated longitudinally of the machine.

two parallel rows of partitioned compartments. On the columns it) there is mounted for vertical movement an elevator chassis 14 comprising a framework of tubular structural members 16 enclosed in an outer casing 13 of sheet steel. The chassis 14 is suspended on the columns by elevator cables 20 and bracket-mounted rollers (not shown) atlixed to the chassis contact the columns and guide its up and down movement. The cables 20 are actuated by a fluid cylinder, as shown and described in the above-mentioned patents to which reference is made for a description of various details of the machine embodying the present invention. Workpieces are moved around the machine on a work-carrying rail made up of fixed and spaced rail sections 22 mounted along the top of the tanks 12 and vertically-movable rail sections 24 afxed by brackets to the underside of the elevator chassis 14. At each of the arcuate ends of the machine curved rail sections 26 are aixed to the top of the tanks. When the chassis is lowered the movable rail sections 24 and the fixed rail sections 22, 26 are aligned to form a continuous rail around the machine to which current is supplied in known manner. The workpieces are suspended in work carriers which in turn are supported on the rail sections by suitable hangers 28, which are slidable 4on the rail sections upon engagement by the pusher system to be described. 4

The transfer pusher system comprises pusher bars 30, 30a mounted for reciprocating movement along the straight sides of the machine and above the rail sections. The pusher bars 30, 30a may be of T-section and are slidably mounted in shoes 32 (Fig. 7) aixed to the underside -of the chassis.` Fixed and pivoted pushers are carried by the bars 30, 30a which are adapted to operate on the hangers 28. Each of the pivoted pushers, as at 36, pivots on a pin on the back stroke of the pusher bar to cleara hanger and is retained in an upright position on the foiward stroke by a suitable stop vto engage and push the work hanger. The pusher bars 'are operative in both the raised and lowered positions of the chassis 14, the pushers in the raised position being effective to move the work carriers on the movable rail section 24 so they pass over the tank partition walls 37, and in the lower position being effective to advance all of the work carriers on the aligned rail sections 22,24 and 26.

The pusher bar 3i) is actuated from a iiuid operated actuating cylinder 40 mounted on the chassis adjacent to and longitudinally of the pusher bar 30, the piston rod `of which is connected to the pusher bar 30 by a bracket 41 (Fig. 2). A preferred construction for linking the piston rod of the actuating cylinder with'one of the -pusher bars, in this instance to pusher bar 30a is shown in Fig. 7. The cylinder 40 is pivotally secured at the rear end thereof to a cross bar on the chassis 14. The piston rod 3S has a clevis tting 43 pivotally secured substatitially at the center of a transverse lever 44. One lend of the lever 44 is pivotally anchored on the chassis by a link 45 which in turn is pivotally secured to a bracket 47 aixed to the chassis 14. The other end of the lever 44 is secured to an upstanding bracket 46 attached to the pusher bar 30a (not showing Fig. 7) on the far side of the structure as viewed in Fig. 7. The piston rod 38 is fully extended in the position shown and when retracted in the direction of the arrow, lever 44 will occupy the position shownV in outline to reciprocate the pusher bar 30a at the farsideof the structure.

Actuation of the piston rod` by either of the constructions described causes one of the pusher bars to be The stroke of the piston can be controlled by' appropriate 'lirrit switches (not shown), the location of which can beadjusted to provide for different lengths of stroke imparted comprising a shaft 50a mounted for rotation in bearings 52a secured to the machine frame, the shaft being concentric with the curved rail section 26, and a pair of radial pusher arms 54a, 56a secured to the shaft 50a. Each of the pusher arms 56a is provided with a lug 47 which is pivotally connected to one end of a link 47a, the other end of which is pivotally secured to an ear 4S on the respective pusher bar 30. The free end of each of the pusher arms 54a carry a pusher that propels a work carrier around the curved rail section at this end of the machine on rotation of the shaft when the chassis 14 is in the lowered position. Thus, actuation of the piston rod of the actuating cylinder 40 reciprocates the pusher bar 30 to oscillate the pusher arms 54a, 56a causing the other pusher bar to be reciprocated in a longitudinal direction opposite to that of the adjacent pusher bar. By this arrangement, the pusher bars 30 are reciprocated through identical strokes and on cach stroke the hangers 2S and thus the work carriers are advanced equal distances along each straight side section of the machine. When it is desired to reciprocate the pusher bars through unequal strokes, the linkage hereinafter described may be employed in lieu of the above.

At the right-hand end of the machine as viewed in Fig. 2, an underside View of which is shown enlarged in Fig. 3, a vertical shaft 50 is rotatably mounted in bearings 52 and located concentrically of the curved rail section 26 to which is fixed a pair of radial pusher arms 54, 56. The free end of each of the pusher arms 54, 56 carries a pusher, as at 5S, which propels the work carriers around the curved rail section at this end. The adjacent pusher bar 30 which is driven by the actuating cylinder is provided with an ear 60 to which is pivotally secured vone end of a link 62, the other end of which is pivotally secured to a multiplier lever 66 by a pin 63 .carried by aclevis 64. The rear portion 68 of the clevis is'formed with a dovetail way slidably interlocking a dovetail 70 integral with or otherwise secured to the lever 66 (Fig. 6). Bolts or set screws 72 (Fig. 3) extend through the portion 68 and engage the dovetail 70 so as to securely but adjustably position the clevis 64 on the lever 66. By this construction the linear travel of the free end of the pusher arms 54, 56 around the arcuate end is adjustable and hence is the spacing of the work carriers as they travel therearound.

One end of the lever 66 is pivotally fixed to the under- -side of the chassis 14 outwardly of the sheet steel enclosure 18 by a pin 75 carried by a bracket 74. The free end 76 of lever 66 is disposed inwardly of the pivot connection for the fixed end which latter preferably lies with- `in the angle enclosed by transverse and longitudinal centerlines A and B respectively, of the pusher arm shaft 50.

'Pivotally secured to the free end 76 of the lever 66 by a -pin 78 is a link 80 which in turn is pivotally secured by "shaft`50 Yis rotated in the opposite direction so that the pusher arm 54 assumes its retracted position substantially as 'that Vshown in Fig. 3. The linear travel of the freel ends' of the pusher arms 54, 56, it will be noted, is considerably greater than, and adjustable independently of, the Ypusher bar 30.

`When desired, the pusher `bars may be actuated through vunequal strokesY by employing the linkage shown in outline in Fig. 3 in lieu of the linkage connecting the'pusher b ars, at the left-hand end of themachine as viewed in "fFig. 2. Inthis event, the'pusher bar 30a, on the far side of the machine, may be 'connected to the pusher arm 56 bymeans of a link pivotally secured at one of its ends byapin` 92 toa bracket 94 carried bythe pusher arm 30 since the former is directly connected to the pusher arm 56.

The adjustable feature of the multiplier linkage will be described more fully with reference to the schematic views of Figs. 4 and 5. As has been mentioned, the multiplier lever 66 imparts a greater or lesser angular displacement to the shaft 50, for ea given advance of pusher bar 30, according to the location of the clevis '64 thereon. When the clevis 64 is moved toward the fixed end of the lever 66, the amplitude of oscillation of the free end of the lever 66 and consequently the angular displacement of the shaft 50 is greater. Conversely, as the clevis 64 is moved toward the free end of the lever 66 the amplitude `of oscillation of the latter and thus the angular displacement of the shaft 50 is less. By adjusting the distance between the clevis 64 and the fixed end of the lever `66 it is possible to secure considerable variation in the angular displacement imparted to the shaft 50 and hence to the pusher arms 54, 56. This will appear most clearly from a comparison of Figs. 4 and 5. In Fig. 5 the distance between the clevis 64 and the fixed end of the lever 66 has been reduced somewhat as compared to that shown in Fig. 4. As a result, the pusher arm 54 on the return stroke of the pusher bar 30 is retracted across the transverse center-line A approximately l degrees. When the pusher bar 30 is advanced, the pusher arm 54 will be actuated across the longitudinal center-line B by about the same amount, advancing a work carrier this distance. Since the pusher arm 56 is oscillated through the same arc, the preceding work carrier will be advanced a distance around the arcuate end of the machine and beyond the transverse center-line B by an angular displacement equivalent to l() degrees. The net result of decreasing the distance between the clevis 64 and the fixed end of the lever 66 is that the pusher arm 54 reaches further back on the pusher bar 30 to advance a work hanger and the pusher arm 56 pushes the hanger farther down the length of pusher 30a on the other side of the machine.

The manner in which` this greater arc of oscillation relieves the congestion in the arcuate end section will be seen more clearly by reference to Figs. 8 and 9. In Fig. 8 the pusher arms 110, 112 mounted on shaft 114 are oscillated through an arc of only about 90 degrees by a linkage, for example, such as is shown in the patents referred to above. Extremely large plating racks 116, such as are shown, will crowd and contact one another as at C and D. In Fig. 9, however by the means provided by the present invention, the pusher arm 54 is re tracted a greater linear distance across transverse centerline A to effect a greater clearance distance as at X between the adjacent plating racks 116. Likewise, the pusher arm 56 is advanced beyond transverse center-line A an equivalent linear distance to produce a similar clearance distance so that adequate clearance is obtained throughout the arcuate end section. The angular over lap Y between retracted arm 56 and advancedrarm 54 can be reduced or substantially eliminated and even greater spacing in the arcuate end section can be accomplished by varying the angular spacing olf the arms 54 and 56.

It will thus be seen that there has been provided by this invention a conveying apparatus in which the various objects hereinabove set forth, together with many thoroughly practical advantages are successfully achieved. While the preferred embodiment of the invention has .been shown and described, it is to be understood that various modifications, changes in size, shape and arf rangement of parts may be resorted to without departing from the spirit of the invention or scope of the appended claims.

What is claimed is:

l. In a conveying apparatus having straight rail sections and an arcuate turn-around rail section joining said straight rail sections, and means for advancing work carriers along said straight rail sections, a shaft rotatably mounted within said arcuate section, pusher means fixed to said shaft and extending toward said arcuate section, a multiplier lever, a fixed pivot connection securing one end of said lever to said arcuate section, said lever extending inwardly of said arcuate section toward said shaft, a first linkage pivotally connecting the said advancing means with said lever between the ends thereof, a second linkage pivotally connecting the opposite end of said lever with said pusher means, and means for reciprocating said advancing means whereby said pusher means is actuated through an angular displacement substantially greater than degrees.

2. Apparatus as claimed in claim 1 wherein the said pivot connection is located within the enclosed angle on one side of said rail section defined by lines extending transversely and longitudinally of said apparatus at right angles to each other and passing through said shaft.

3. Apparatus as defined in claim 2 wherein the connection between said first linkage and said lever is adjustable along the length of said lever to vary the angular displacement through which said shaft and said arm are actuated.

4. lIn a conveying apparatus, work supporting rails for supporting work actuated around a circuit including two straight rail sections and an arcuate turn-around rail section, a pusher bar slidably mounted along each of said straight rail sections, pushers carried by said bars arranged to engage work carriers on said straight rail sections, a shaft rotatably mounted adjacent the center of curvature of said arcuate section, a pair of radiallyextending pusher arms fixed on said shaft spaced one from the other at right angles, a pusher on each of said arms arranged to engage work carriers on said arcuate turn-around rail section, a multiplier lever, a fixed pivot connection pivotally securing one end of said lever on one side of said arcuate section, the free end of said lever extending inwardly of said pivot connection toward said shaft, a first linkage member pivotally connecting the one of said pusher bars on said one side with said lever inwardly of the free end thereof, a second linkage pivotally connecting the free end of saidlever with one of said arms, and means for reciprocating said one pusher bar whereby said arms are oscillated through an arc substantially greater than 90 degrees in response to the reciprocation of said one pusher bar.

5. In a conveying system which includes a shaft having a pushermember secured thereto and extending radially outwardly therefrom, a fixed support arranged to one side of said shaft, and work carrier advancing means movable along a substantially straight line to one side of said shaft; multiplier means for obtaining an angular movement of said pusher member in excess of the angular movement obtainable from a direct connection between said advancing means and said pusher member for a predetermined straight line movement of said advancing means in one direction, said multiplier means comprising a pair of pivotally connected links pivotally connected to and extending between said fixed support and said pusher member, means connected to and extending between said advancing means and the one of said pairs of links connected to said fixed support for rotati-ng said one link on movement of said advancing means in said one direction, and said links being arranged so that the angle therebetween is increased in response to movement of said advancing means in said one direction to provide for an "7 increased angular movement of said pusher member relative to said Vone link.

6. In a plating machine having' work-supporting rails for supporting work actuated around a circuit including spaced straight rail sections, and aniarcuate turn-around rail section joining one end of said straight rail sections, a pair of longitudinally spaced pusher bars slidably mounted adjacent said straight rail sections, pushers earried by said bars arranged to engage work carriers on the several rail sections, a shaft rotatably mounted in the center of curvature of said arcuate turn-around section, a pair of radially-extending pusher arms fixed on said shaft spaced one from the other at right angles, a multiplier lever, a fixed pivot connection pivotally securing one end of said lever on one side of said arcuate section in the quadrant thereof defined by lines extending transversely and longitudinally of said apparatus at right angles to each other and passing through said shaft, the free end of said lever extending inwardly of said pivot connection toward said shaft, an ear on the one of said pusher bars on said one side, a first linkpivotally secured at one end to said ear, a clevis pivotally secured to the other end of said link, said clevis being adjustably positioned along the length of said lever, a second link pivotally connecting the free end of said lever to one of said arms, and means for reciprocating said one pusher bar whereby said arms are oscillated through an arc substantially greater tha-n 90 degrees in response to t'ne reciprocation of said one pusher bar.

7. In a conveying system which includes a pair of horizontally spaced parallel pusher bars mounted for reciprocal movement in directions longitudinally thereof, a pusher member mounted for swinging movementaoout a vertical axis located between the vertical planes in which said pusher bars are mounted, and alixed support arranged to one side of said axis;- means for obtaining an adjustable relation of the strokes of said two pusher bars, said means comprising a pair of pivotally connected links pivotally connected to and extending between said fixed support and said pusher member, a connecting member connected to said one pusher bar and adjustably attached to the one of said pair o\f links connected to said fixed support for rotating said one link on movement of said one pusher bar in said one direction, said links being arranged so that the angle therebetween is increased in response to movement of said one pusher bar in said one direction to provide for an increased angular movement of said pusher member relative to said one link, and means connecting said pusher member and the other one of said pusher bars so that said other pusher bar is moved in the opposite direction a distance relative to the movement of said one pusher bar in said one direction which is determined by the position along the length of said one link at which said connecting member is connected thereto.

8. In a conveying system which includes a pair of horizontally spaced parallel pusher bars mounted for reciprocal movement in directions longitudinally thereof, a pusher member mounted for swinging movement about a vertical axis located between the vertical planes in which said pusher bars are mounted, and a fixed support arranged to one side of said axis; means for obtaining a movement of one pusher bar a distance which is different than the movement of the other pusher bar in response to movement of said other pusher bar in one direction, said means comprising a pair of pivotally connected links pivotally connected to and extending between said fixed support and said pusher member, means connected to and extending between said one pusher bar and the one of said pair of links connected to said fixed support for rotating said one link on movement of said Y other pusher bar in said one direction, said links being arranged so that the angle therebetween is increased in response to movement of said one pusher bar in said one direction to provide for an increased angular movement of said pusher member relative to said one link, and means connecting said pusher member and said one of said pusher bars so that said one pusher bar is moved Ain the opposite direction anV increased distance relative to the movement of said other pusher bar in said one direction. i 4

References Cited in the file of this patent UNITED STATES PATENTS 2,591,681 Davis Apr. 8, 1952 2,591,682 Davis Apr. 8, 1952 2,650,600 Y, Davis Sept. l, 1953 2,672,759 Tranter Mar. 23, 1954 2,691,244 Steinke Oct. l2, 1954 2,775,333 Hayes Dec. 25, 1956

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