US2800216A

US2800216A - Feeding apparatus

Info

Publication number: US2800216A
Application number: US300262A
Authority: US
Inventors: Herman E Muller
Original assignee: York Engineering and Construction Co
Current assignee: York Engineering and Construction Co
Priority date: 1952-07-22
Filing date: 1952-07-22
Publication date: 1957-07-23
Anticipated expiration: 1974-07-23

Description

y 1957 H. E. MULLER 2,800,216

FEEDING APPARATUS s sneeis sheet 1 Filed July 22. 1953 IN VEN TOR. Herman 2 Muller MM A Mk ms ORNEYS H. E. MULLER FEEDING APPARATUS 6 Sheets-Sheet 2 July 23, 1957 Filed July 22.- 1952 H. E. MULLER FEEDING APPARATUS July 23, 1957 Filed July 22. 1952 6 Sheets-Sheet 3 R. f L 5 m)? mm N V. j n a A MW Y I B y 1957 H. E. MULLER 2,800,216

FEEDING APPARATUS Filed July 22. 1952 6 Sheets-Sheet 4 v IN VEN TOR.

Herman E. Muller M 11/ km H/S A ORNE Y5 H. E. MULLER FEEDING APPARATUS July 23, 1957 e Sheets- Sheet 5 Filed July 22. 1952 V I g. l Herman 2 M 3/5 A ORNEYS FEEDING APPARATUS Filed July 22,- 1952 6 Sheets-Sheet 6 INVENTOR. Herman E Muller "AZ/ W *IQMLA HIS )1 ENE Y5 Unite States Patent "v FEEDING APPARATUS Herman E. Muller, Swissvale, Pa., assignor to York Engineering & Construction Company, Pittsburgh, Pa,

a corporation of Pennsylvania Application July 22, 1952, Serial No. 300,262

13 Claims. (Cl. '19830) This application relates to feeding apparatus, particularly apparatus for feeding long, light or heavy objects,

such as billets, bars, slabs, etc. The apparatus is intended to receive-at one time a number of such articles and to deliver themvone at a time to some other apparatus for processing.

Apparatus for accomplishing this is now available. However, such apparatus as is now known is limited to feeding articles which come within a limited range of cross-sectional shapes and sizes. As .is well known, billets, bars, slabs, etc., vary widely in size and shape, with the result that a machine such as is now available which can handle billets cannot handle bars. a machine adapted for slabs cannot handle billets.

My feeding apparatus, on the other hand, adjusts itself automatically within a considerable range to width of materials handled. A certain range can bepre-adjusted manually in a very short period of time when setting up .the machine for materials within respective range limits.

One or more endless conveyors are arranged side by side, depending on length and 'slenderness of sections to be conveyed. Each endless conveyor is supported by two sprockets and each conveyor is considerably longer than the distance between the sprockets so as to form a trough into which a number of bars ,or billets can be loaded at one time. The conveyors then deliver bars or billets from this group one at a time. This is accomplished by providing lugs spaced at intervals along the conveyor, which lugsengage the bars or billets when the conveyor moves and push them one at a time out of the trough onto a holding rack from which they may be lifted ,one at a time and deposited on other apparatus for further processing.

As noted, special arrangements are provided so that the same apparatus can handle objects of different dimensions. Thus as the bars or billets are raised out of the trough formed by the endless conveyor, they ride on skids, the height of which can be adjusted relative to the conveyor flights. If, for example, the machine is adjusted to handle billets 6" square, the skids will be adjustedso that the lugs Likewise,

of .a wide variety of size and shape can be handled on the holding rack.

In the accompanying drawings, I have illustrated a presently preferred embodiment of my invention, in which- Figure 1 is a plan view of two adjoining flights of the embodiment with associated parts;

Figure 2 is a section of'Figure 1 on the line II'II;

Figures 3 and 4 are sections of Figure 2 on the lines IIIIII and IVIV, respectively, with the remaining wall member included for completeness;

Figures 5 and 6 .are partial plan and side elevations, respectively, of the chain flights used as the advancing means;

Figure 7 isa sideelevation of the skids and controls therefor with otherparts removed to facilitate the illustration;

Figure 8 is a plan ,view of Figure 7;

Figure 9 is a section of Figure 7 on the line IXIX;

Figure 10 is an enlarged view of the delivery or ejection means shown in Figure2 with a support wall partially broken away; 7

Figure 11 is a plan view of Figure 10 on the line XI XI with another supporting wall member included forcompleteness; and

Figure 12 is a view similar to that of Figure 10 but representing a short interval of time thereafter;

' Referring principally to Figures 1 and 2, the embodiment comprises two .endless parallel chain conveyors 15 and '16, made up in segments or flights 17. .Someof the flights .have lugs 18 to pick up a billet from those in a trough generally shown at T. A drive sprocket 19 and an idler sprocket 120 support each chain which is -considerably longer than the distance around those sprockets and an idler roller 21. In order to form the trough with the excess lengthand to release the tension .at all times in the upper part of the chain, the sprocket on the conveyor flights extend above the skids slightly less than 6". When the conveyor moves, the lugs will then engage only one billet at a time. If slabs 2" thick are to be handled in the apparatus, then the skids are adjusted so that the lugs project above the skids slightly less than 2". When the conveyor is driven, the lugs will engage only one slab at a time. If the skids had not been adjusted when changing from billets to slabs, then the lugs projecting above the skids almost 6" will engage two or three slabs at a time.

The apparatus for lifting bars or billets from the holding rack comprises plates which are raised up beneath the bars or billets to raise them above a stop on the rack and place them on skids which will deliver them to another machine. The plates are automatically extended by the weight of the bars or billets so that they will engage these articles at least as far as their longitudinal center and thereby lift them over the stop. Since the plates are automatically extendable, bars, billets andslabs rearwardlyof the direction of chain travel ismade the drive sprocket.

The source of the drive isa motor .22 supported on a frame 23 and block 24. The motor turns suitable worm gearing, contained in a gear reduction box 25, through a shaft 26 and coupling 27. The worm gearing includes laterally extending

shafts

28 and 29 and couplings 30 which rotate the drive sprockets 19.

Support walls

31, 3,2, 33, and 34 suitably secured to a base 35 straddle 'the chains and sustain the bearing flanges 36 .and 37 in which the axles of the drive sprockets are journaled. The support walls also carry the billets and have their upper edges preferably flush with the top surface of the chain flights. Although the preferred practice is .as shown to use two or more chains, it is possible when processing short lengths of billets or ingots to ,useonlyone relatively wide chain.

Angle bars

38, 39, 40, and 41 attached to each support wall support the chain between the

sprockets

19 and 20 and generally define its path ,of travel. The legs 42 of the angle bars have slotted bolt holes sothat their position can be adjusted. The support walls vhave a hump 43 at the discharge end of the apparatus over which billets 44 rideto reach a rack 45 having a stop 46. When a number of billets have accumulated on the rack, one of them contacts a limit switch 47 which halts the movement of the chains.

Delivery apparatus is located directly beneath the billets on the rack 45 and consists of two pairs or sets of substantially parallel plates shown generally at 48. The construction and operation of these plates are later described in detail in connection with Figures 10, 11, and

p the free end of the skids.

they drop singly onto other processing equipment such.

as a roller table 59. I

' Figures 3 to 6, inclusive, show'one of the conveyors and the support therefor. Each conveyor comprises a series of flights 17 which, in effect, are links in an endless chain with plates on one side. The flights are spaced from each other by plain links 61 and some of the flights have lugs 18.

As shown in Figures 3 and 4 angle bars 38, 39 and 40 bolted to the

side plates

33 and 34 form tracks for the conveyor. These angle bars carry

wear plates

63 and 64. On forward movement of the conveyor, the links ride on these wear plates. On return movement of the conveyor, the plates 69 ride on the wear plates.

Figures 7 through 9 show an adjusting mechanism for the skid members whereby articles varying in size and shape over a considerable range may be handled.

Skid members

65 and 66 pivot about the support walls, such as 33 and 34, near the bearing 67 for the idler sprocket 20. The width of each skid is tapered at its free end to present a camming surface to the approaching billet. The carnming surface also aids in obtaining a more sensitive control by the adjusting mechanism. -The.latter includes connecting

rods

68 and 69 which pivot about The rods in turn pivot about crank

arms

76 and 71 secured to a rocking shaft 72 passing transversely through the support walls. A bell crank 73 is also secured to the shaft 72 and has an indicating finger 74 registering with a scale 75 calibrated in any desired units. The remaining end of the bell crank '73 pivotally straddles a trunnion nut 76 mating with a threaded shaft 77 supported by a bearing 78. The shaft 77 terminates in a hand wheel 79. Turning the latter moves the trunnion nut 76 axially on the shaft 77. By means of the described linkages, the skids are rotated about their point of connection to the support walls and may assume, for example, a position 80 shown by the dotted lines. In comparison with the billet 81 shown in contact with a lug 82 when the

skids

65 and 66 are in a lowered position, the billet is elevated from the conveyor flights and occupies a new station as shown at 81a along the tip of a lug 82a when the skids are moved to a higher position. Accurate determination of the position of the skids may be made by noting the position of the finger 74 on the calibrated scale 75.

Referring now to Figures 10 through 12, the delivery apparatus is directly below the stop 46 of the rack 45 and consists of two pairs of spaced-apart, substantially parallel plates. The first pair consisting of

plates

83 and 84 is placed between the

support walls

33 and 34 and secured to an axle 85 journaled for rotation in the walls. The

plates

83 and 84 are spaced on the axle 85 at the ends by

collars

86 and 87 and in the middle by a U-shaped member 83.

Another pair consisting of plates 89 and Qi) is inserted between the first pair and all four plates pivot on an axle 91. The

plates

89 and 90 carry a bar 92 which is preferably convex in a direction toward the billets 44 to aid in the delivery step as hereafter explained.

Plates

89 and 90 through an axle member pivot about a ram 49 which is operated in a manner previously described in connection with Figure 2. A spring 93 connects the axle 85 to a pin 94 carried by brackets 95 fixed to the bar 92. The support wall 33 also carries a ledge 96 which supports a limit switch 47 having an arm 97 provided with a follower 98 normally reaching above the rack 45.

Although the preferred practice is to use two pairs or sets of plates, one inserted between the other, to obtain a larger displacing area, it is possible to form delivery apparatus of the present invention using only two plates. in this case one of the plates pivots about the other while the latter pivots about a fixed point. A spring joins the first plate to a point near or coincident with the fixed point.

The delivery apparatus is designed to lift the billets up from the rack 45 above the stop 46 so that they can slide down the rack beyond the stop 46 onto the roller'table 59. As is apparent from Figure 10 of the drawings, the plates 83 and 84- cannot raise the billet above the stop 46 unless they engage the bottom surface of the billet at or beyond the longitudinal center of the billet. If the

plates

83 and 84 engage the bottom of a billet at any point between the stop 46 and its longitudinal center, the result will be only to tilt the billet clockwise (viewing Figure 10) up against succeeding billets or to roll it upwardly on the rack 45. In the delivering apparatus just described, the

plates

89 and 90 rotate about the axle 91 and project the bar 92 out between the plates 83 and $4 whenever the

plates

83 and 84 do not have sufiicient length to extend to orbeyond the longitudinal center line of the particular billets, slabs, bars, etc., being handled. This action, in efiect, extends the length of the upper edge of the

plates

83 and 84 so that billets, bars, slabs, etc., regardless of their width, are engaged at or beyond their longitudinal center. It is important that the length of the

plates

83 and 84 be thus adjustable, otherwise the delivery apparatus could not handle billets, bars, etc., having a relatively small width. If the

plates

83 and 84 initially had sufiicient length to raise the widest billets, slabs, etc., for which the machine was designed, then, if smaller billets or slabs were being handled, the

plates

83 and 84 would raise more than one billet or slab at a time.

When a billet is required, the cylinder 56 is actuated to raise the ram 4? which, in turn, will rotate the

plates

83 and 84 about the axle 85 until the

plates

83 and 84 contact the bottom surface of the-billet on the rack next to the stop 46. Continued upward movement of the ram 49 will then rotate the

plates

89 and 90 about the pin 91, this rotation being resisted by the spring 93. The dimension of the billets shown in Figure 10 are such, how ever, that the

plates

83 and 34 will engage the bottom surface of the billet which is next to the stop 46 beyond the longitudinal center of the billets so that, as shown in Figure 12, there is very little rotation of the

plates

89 and 94 against the action of the spring 93 before the billet 44a is raised up above the stop 46 and can then slide down the upper edges of the

plates

83 and 84 onto the lower part of the rack 45, beyond stop 46, and thence onto the roller table 59.

If, however, the delivery apparatus was handling slabs having a considerably greater width than thickness, raising the ram 49 and the

plates

83 and 84 up against the bottom surface of such a slab would tend only to tilt the slab clockwise against succeeding slabs. To avoid this, continued upward movement of the ram 49 in the present apparatus rotates the

plates

89 and 30 about the axle 91 until the-bar 92 extends a sufiicient distance beyond the upper corner of the

plates

83 and 84 to engage the bottom of the slab at or beyond its longitudinal center. After the bar92 had thus been moved out beyond the

plates

33 and 84, the action of the mechanism on the slab is the same as shown with respect to a billet in Figure 12 of the drawings.

To insure that the inner pair of plates is never pushed too far about the axle member 91, one or both of the inner plates may have a pin 99 registering in a slot 100 in the plates of the outer pair. The pin 99 prevents further individual rotation of the inner pair about the axle 91 when the pin reaches the upper end of the slot 100.

In an over all operation of the entire'feeding apparatus, a batch of billets is dumped'in irregular order into the trough As the ,motor 22 drives the chains, the billets are tumbledabout in the direction of the arrows 101 iof Figure '2. During this time, one or more billets Kare initially retained by the lugs 18 of themovingflights. If more than one billet is retained, however, the excess falls off as the flight passes between

skids

65 and 66 and as the skids elevate the billets from the chains. The extent of this elevation may be regulated by adjusting the position of the skids through the handwheel 79.

When the chains have pushed a suflicient number of billets 44 over the hump 43 to fill the rack toa point Where the arm 97 is depressed, the limit switch 47 opens a circuit stopping the motor 22. Billets are obtained when needed by admitting fluid under, pressure into the cylinder 56 to draw in the piston 55 and operate the ram 49.

After the loadingrack 45 has been sufiiciently emptied to allow the arm 97 to raise, and the limit switch automatically starts the motor 22 again and more billets are fed to the rack 45.

While the foregoing disclosure describes a presently preferred embodiment, it is understood that the invention may be practiced in other forms within the scope of the following claims.

I claim:

1. Feeding apparatus for billets and the like comprising at least two continuous chains spaced substantially parallel to each other, each chain consisting of a plurality of flights pivotally joined end-to-end with some of the flights having a lug to retain a billet placed transversely to the chains; means to move each chain longitudinally in the same direction through predetermined corresponding paths, each path including at least two fixed points substantially in the same horizontal plane and wherein the locomotive power is transmitted through the fixed point which is rearward of the direction of chain travel whereby each chain defines a trough between the two fixed points for receiving a plurality of billets in superposed layers; walls straddling each chain and having theirupper edges flush with the chain flights, throughout the upper length of their path of travel; skid members astriding each chain at corresponding predetermined points in their respective paths along a side of the trough to elevate the billets retained by the lugs outwardly along a major face of each lug to a desired distance from the chain whereby all but the bottommost layer of billets are tumbled back into the trough; and means to adjust the position of the skid members with respectto a chain whereby the extent of the elevation may be regulated.

2. Delivery apparatus comprising a support sloping toward a point of delivery and having a stop to prevent articles to be delivered from sliding down the support, a rod movable upwardly toward an article, ahead adjustab ly positioned on the rod to engage the article and raise it over the stop, whereby .the position assumed by the head is determined by the size of the article so as to engage the bottom surface thereof at least as far as the longitudinal center.

' 3. Apparatus for delivering bars, billets, and like articles comprising a support for the articles sloping toward a point of delivery, a stop on the support preventing the articles from sliding down the support, delivery means movable upwardly to engage an article and raise it over the stop consisting of a plate adapted to pivot about another plate, the second plate pivoting about a point on the support, and resilient means connecting the first plate to the support whereby the first plate pivots about the second plate to an extent determined by the, size of the article to engage it at least as far as the longitudinal center of gravity.

4. Apparatus for delivering bars, billets, and like articles comprising in combination: a support for the articles to be delivered sloping toward a point of delivery, a stop on the support preventing the articles from sliding down the support, and delivery means for engaging an article and raising it over the stopcomprising a pair of spacedapart plates pivoting about one side of the support, a'secasoogre 6 0nd pair of spaced-apart plates inserted between the first and pivoting thereabout to engage an article, and spring means "connecting the plates of the second pair .with the livered sloping toward a point of delivery, and .a stop on the support to prevent the articles from sliding down the support, delivery means which is self-adjusting to the size of the articles to be delivered comprising: a pair of spaced-apart, parallel plates each pivotable (at corresponding points about an axle member; a second pair of spacedapart, parallel plates inserted between the first; a-second axle member about which all plates pivot; and spring means connecting the plates of the second pair with the first mentioned axle member whereby a dual movement is obtained wherein the entire assembly pivots about the firstmentioned axle member and the second set of plates pivots about the second axle member.

6. In apparatus for delivering bars, billets, and like articles, a support wall for the articles to be delivered sloping toward a .point of delivery, a stop on the support wall to prevent the articles from sliding down the edge of the wall, delivery means which is automatically selfadjusting to compensate for the size and weight of the article :to be delivered therefrom comprising: a pair of spaced-apart, parallel plates, each plate being joined at corresponding points to an axle member rotatably supported thy the support wall; a second pair of spaced-apart, parallel plates inserted between the first; a bar connecting the plates of the second pair; a second axle member about which all four plates pivot; pushing means joined to a plate of the second set; and spring means connecting the bar with the first mentioned axle member whereby a dual movement is obtained wherein both sets of plates pivot en masse about the first mentioned axle member, and the second set of plates pivots about the second axle member, the extent of the second described movement being determined by the size and weight of the article delivered and the tension of the spring means.

7. In apparatus for delivering bars, billets, and like articles comprising a support consisting of two spaced apart, substantially parallel support walls for the articles to be delivered, both walls sloping to a point of delivery, and a stop on the walls to prevent the articles from sliding down the upper edges of the walls, delivery means which is'automatically self-adjusting .to compensate for the size, weight, andsurface contour of the article to be delivered therefrom comprising: a pair of spaced-apart,

parallel plates placed .between the support walls, each plate having a slot and being joined at a corresponding point to an axle member which passes through the plates in a direction substantially normal to their surfaces and is rotatably supported by the support walls; a second pair of spaced-apart, parallel plates inserted between the first, each plate of the second pair having a pin registering with a slot of a plate of the first pair; a bar connecting the upper faces of the plates of the second pair and having a convex surface pointed toward the articles on the stop; asecond axle member about which all four plates pivot; ram means joined to plates of the second set; means to operate the ram; and a spring connecting the bar with the first mentioned axle member whereby a dual movement is obtained upon operating the ram means wherein both sets of plates pivot en masse about the first mentioned axle member and the second set of plates pivot about the second axle member, the extent of the second described movement being determined hy the size, weight,

by the strip one level .at a time; and the delivery means comprising a support sloping toward a point of. delivery and havinga stop to prevent articles to be delivered from sliding down the support, a rod movable upwardly against the articles to raise them over the stop, said rod having a head which is adjustably positioned so as to engage the bottom surface of the articles at least as far as the longitudinal center thereof.

9. Feeding apparatus comprising feeding means and delivering means, the feeding means comprising a segmented continuous strip having a plurality of units joined" together, some of the units having lug means, means to move the strip,iand skid means associated with the strip to alter the position of the article with respect to the strip at a predetermined point; and the delivery means comprising a support for the article sloping toward a point of delivery, a stop on the support preventing the article from sliding down the support, ejecting means movable upwardly against the article to raise it over the stop consisting of a plate which is adjustable in efiective length to engage on one of its sides the bottom surface of the article at least as far as the longitudinal center of gravity thereof, said plate pivoting about another plate, the second plate pivoting about a point on the support, and resilient means connecting the first plate to the support 10. Feeding apparatus for bars, billets, and like articles comprising feeding means and delivery means, the feeding means comprising a segmented continuous strip having a plurality of sections joined together, some of the sections having lug members, means to move the strip longitudinally, and a skid member stationed about the strip to elevate the articles with respect to the strip at a predetermined point in the travel of the strip; and the delivery means comprising in combination: a support for the articles to the delivered sloping toward a point of delivery, a stop on the support preventing the articles from sliding down the support, and ejector means comprising a pair of spaced-apart plates pivoting about one side of the support, a second pair of spacedapart plates inserted between the first and pivoting thereabout, and spring means connecting the plates of the second pair with the support. 11. Feeding apparatus for bars, billets, and like articles comprising feeding means and delivery means, the feeding means comprising a continuous chain having sections oined endwise, some of the sections having lug means to move the chain longitudinally through a predetermined path, skid members stationed about the chain to elevate the articles to a desired distance from the chain at a predetermined point in the path, and means to regulate the position of the skid members; and the delivery means comprising in combination: a support for the articles to be delivered sloping toward a point of delivery, and a stop on the support to prevent the articles from sliding down the support, and ejecting means which is self-adjusting to the size of the article to be delivered consisting of a pair of spaced-apart, parallel plates each pivotable at corresponding points about an axle member, a second pair of spaced-apart, parallel plates inserted between the first; a second axle member about which all plates pivot; and spring means connecting the plates of the second pair with the first mentioned axle member whereby a dual movement is obtained wherein the entire assembly pivots about the first mentioned axle member and the second set of plates pivots about the second axle member. 12. Feeding apparatus for bars, billets and like articles comprising feeding means cooperating with delivery means, the feeding means comprising a continuous chain consisting of a plurality of sections pivotally joined end-to-end, some of the sections having lugs to retain the elongated members placed transversely to the chain, means to move the chain longitudinally through a predetermined path which includes at least two fixed points substantially in the same horizontal plane and wherein the locomotive power is transmitted through the fixed point which is rearward of the direction of chain travel, a 'Wall member aside the chain and substantially flush with the upper length of the path, skids straddling the chain at a predetermined point in its path to elevate the articles to a desired distanc from the chain and outwardly toward the tip of a lug, and adjustable means to regulate the position of the skid members with respect to the chain; and the delivery means comprising in combination: a support wall for the articles to be delivered sloping toward a point of delivery, a stop on the support wall to prevent the articles from sliding down the edge of the wall, and ejecting means which is automatically self-adjusting to compensate for the size and weight of the article to be delivered therefrom consisting of a pairof spaced-apart, parallel plates, each plate being joined at corresponding points to an axle member rotatably supported by the support wall, a second pair of spaced-apart parallel plates inserted between the first, a bar connecting the plates of the second pair, a second axle member about which all four plates pivot; pushing means joined to a plate of the second set, and spring means connecting the bar with the first mentioned axle member whereby a dual movement is obtained wherein both sets of plates pivot en masse about the first mentioned axle member, and the second set of plates pivots about the second axle member, the extent of the second described movement being determined by the size and weight of the article delivered and the tension of the spring means.

13. Feeding apparatus for bars, billets, and like articles comprising feeding means cooperating with delivery means, the feeding means comprising at least two continuous chains substantially parallelly positioned, each chain consisting of a plurality of flights pivotally joined end-to-end with'some of the flights having a lug to retain a billet placed transversely to the chains, means to move each chain longitudinally in the same direction through predetermined corresponding paths, each path including at least two fixed points substantially in the same horizontal plane and wherein the locomotive power is transmitted through the fixed point which is rearward of the direction of chain travel whereby each chain defines a trough between the two fixed points for receiving an article and feeding it against the lugs, walls straddling each chain and having their upper edges flush with the chain flights throughout the upper length of their path of travel, skid members astriding each chain at corresponding predetermined points in their respective paths to elevate the articles retained by the lugs outwardly along a major face of each lug to a desired distance from the chain, and means to adjust the position of the skid members with respect to a chain whereby the extent of the elevation may be regulated; and the delivery means comprising in combination: a support consisting of two spacedapart, substantially parallel support walls for the articles to be delivered, both walls sloping to a point of delivery, and a stop on the walls to prevent the articles from sliding down the walls, and ejecting means which is automatically self-adjusting to compensate for the size, weight, andsurface contour of the article to be delivered therefrom consisting of a pair of spacedepart, parallel plates placedbetween the support walls, each plate having a slot and being joined at a corresponding point to an axle member which passes through the plates in a direction substantially normal to their surfaces and is rotatably supported by the support walls, a second pair of spaced-apart parallel, plates inserted between the first, each plate of the second pair having a pin registering with a slot of a plate of the first pair, a bar connecting the upper faces of the plates of the second pair and having a convex surface pointed toward the articles on the stop,

. a second axlemember about which all four plates pivot,

ram means joined to plates of the second set, means to operate the ram, and a spring connecting the bar with the first mentioned axle member whereby a dual movement is obtained upon operating the ram means wherein both sets of plates pivot en masse about the first men-- 5 tioned axle member and the second set of plates pivot about the second axle member, the extent of the second described movement being determined by the size, weight, and contour of the surface of the article contacting the bar and the tension of the spring.

References Cited in the file of this patent UNITED STATES PATENTS Svenson Jan. 29, 1895 Weir Feb. 26, 1907 Anderson Jan. 19, 1909 Shumaker Nov. 21, 1922 Nakane Feb. 22, 1938 Lehmann Oct. 23, 1951