US1873922A - Work feeding device - Google Patents

Description

Aug. '23, 1932. J. M. BACIGALUPI 1,873,922

worm FEEDING DEVICE Filed Jan. 15, 1930 FILE .5

INVENTOR. Jseya/z M Bac/ya/LV w ATTORNEY Patented Aug. 23, 1 932 UNITED STATES PATENT OFFICE JOSEPH M. BACIGALUPI, OAKLAND, CALIFORNIA, ASSIGNOR TO MARCH ANT CALCU- LATING MACHINE COMPANY, A CORPORATION OF CALIFORNIA WORK FEEDING DEVICE I Application filed January 15, 1930. Serial No."420,887.

The present invention relates to metal working machinery and particularly to feeding fingers adapted for use in automatic screw machines, forming or cutting-off ma-' chines, and the like.

An object of the invention is to provide a bipartite stock feeding device in which the stock gripping function is performed by a readily replaceable member of nominal cost, andd sized to accommodate the stock to be use Another object of the invention is to providea bipartite stock feeding device in which the stock gripping function is performed by a replaceable member of relatively soft ma,-

terial, incapable of scratching polished stock,

while thenecessary resiliency for gripping is provided by a second element capable of receiving and retaining suflicient. temper.-

Another object of the invention is to provide a stock feeding device in which the tempered portion thereof is sufliciently insulated from frictionally induced heat to permit retention of its temper. Another object of the invention is to provide a stock feeding device in which the part subject to deterioration is capable of replacement at a nominal cost.

Another object of the invention is to provide a device of the above attributes or any of them which may be incorporated in modern standard machines without modification of the machine.

Other objects will appear as the description progresses, reference being had to the accompanying drawing in which;

Figure I is an elevation of the auxiliary feeding finger.

Figure 2 shows the auxiliary feeding finger inserted in a standard feeding fingerand under the compressive spring action of the latter. I

Figure 3 is a longitudinal section through the feeding finger assembly and a part of the feed tube illustrating the manner in which the stockis gripped.

The form of construction selected for illustration in the present application will be rather specifically described, but it is to be understood at the outset, that within the scope of the invention as claimed, variations may be made.

In the present type of automatic metal working machines, great diiiiculty has been experienced in 'finding some satisfactory means of feeding polished stock without scoring and scratching the same. The standard feeding fingers now employed are usually made of steel, and comprise a hollow tubular body member which is threaded at one end for attachment to the stock bar feed tube, while the other end is slotted, slightly tapered, and spring tempered to create a strong compressive or clamping action. Steel, however, has a strong abrasive action on the stock, and when brought into frictional engagement with other stock, has the tendency to mark the latter, especially when,

as is frequently the case, burrs are left in the feeding surfaces by the manufacturer. Therefore, when the feed finger is moved rearwardly over the stock preparatory to gripping and pushing the stock bar forwardly, the latter is badly scored. The only way to overcome this condition, when feeding polished stock, has been to lap the fingers: out at certain intervals to maintain an absolutely. smooth gripping surface. This procedure, however, caused the fingers to wear down much faster and therefore loose their gripping action, resulting in slippage and inaccurate feeding.

The manufacturers then tried using softer materials such as bronze in the feeding fingers, but this method also proved unsatisfactory due to the fact that such metals could not be tempered to provide the necessary spring tension to. clamp and feed the stock accurately a predetermined distance. It was be easily inserted in the standard feed mech'- anisni as supplied by the manufacturer.

also found that feeding fingers made of bronze would only last a very short time,

necessitating replacements much more often than steel.

Other means have been tried to overcome these great disadvantages in feeding means for polished stock bar, but none seem to have proved successful, mainly for the reason that the improvements required a change in the feeding finger or machine as supplied by the manufacturers with the result that the manufacturer could not avail himself of this im provement without changing the feeding mechanism entirely, or else increasing the sizes and diameter of the entire feeding mechfiIlllSm, including feed tube, collet, and spin- With these drawbacks of, prior structures in mind, the present invention contemplates as shown in the drawing, a simple and inexpensive auxiliary feeding finger which can Referring to the drawing which clearly illustrates the auxiliaryfeeding finger, it can be seen that it comprises a tubular body mem- 7 her 10 which is formed out of'a solid round bar of bronze, or similar material, by drilling a central bore 11. It is then counterbored to about three quarters of its length, with the result that the tubular member .10 has a substantially thicker wall 12 at one end thereof, this end being selectedto provide the smooth gripping or clamping surface 13 which must conform to the shape of the stock bar to be fed. In the present instance, a round bar is illustrated and hence the surface 13 is annular to correspond to the stock.

This tubular member 10, which constitutes my auxiliary feeding finger, is then turned down on the outside to provide at the other end a narrow shoulder or flange 14, after which it is slotted to approximately its center, startingsat the end which carries the gripping surface 13. The slots 15, created permit it to be compressed upon the stock by the resilient fingers 20 of the main feed finger. Apertures 16 are also provided in the opposite end of the auxiliary feeding finger,

so that when the latter is inserted into the standard feeding finger 17 (Figures 2 and 3), these apertures 16, as well as the slots 15, may be aligned with those with which the standard feeding fin er 17 is equipped. The outer surface of tubu ar member 10, of course, conforms to the inside bore of the standard feeding finger 17, as can be readily observed from the drawing. The feeding fin er 17 which is standard equipment of every eeding mechanism for automatic screw machines, etc., needs'no further description other than that it is made of some good grade of steel tubing, has a threaded portion 18 at the end by which it is attached to the feed tube 19 (Figure 3). The other end 20 is slotted exactly like member 10 and is spring tempered, as is well known. Apertures 21 diametrically opposed are provided to allow insertion'of a turn key for screwing the feeding finger onto the feed tube 19.

In practice, when it is desired to work polished stock, the standard feed finger 17 is removed from the feed tube 19 and the auxiliary feeding finger 10 is inserted manually until shoulder 14 abuts the end of the threaded' portion 18 of finger 17. The assembled unit is then screwed into the feed tube 19 by in the assembled feed unit, and the spring action of the main feeding finger is imparted to the inserted one which therefore is in condition to grip the work stock withs'ufiicient pressure to assure accurate feeding "of the stock at predetermined intervals, regardless of slightvvariations in the size of the stock.

When the auxiliary feed finger becomes worn bythe passage of stock therethrough, it

may be easily replaced at nominal cost. The main feed finger, being relieved of all wear, and sufliciently insulated from frictionally induced heat by the interposed auxiliary finger, will last indefinitely.

I claim: -1. A work feeding device comprising a stock feeding member, a feed tube having means'for securing said member thereon, an adapter insertible into said member, and means for maintaining said adapter in proper working relation with said member comprising shoulders on said member and said tube adapted to grip said adapter.

2. A work feeding device comprising a member having a plurality of fingers, an adapter insertible therein provided with a plurality of fingers, a feed tube provided with means for securing said member thereto, means for a igning said member and said adapter durin attachment to said tube comprising aligne apertures in said member and said adapter adapted to receive a key, and means for retaining said member and said ada ter in alignment after attachment to sai tube comprising shoulders on said member and said tube adapted togrip said adapter. v

3. A work feeding device comprising a stock feeding member havinga plurality of fingers, a feed tube provided with means for securing said member thereto, an adapter insertible within said member, and means for preventing longitudinal movement of thd adapter with respect to said member and said tube comprising shoulders formed on said adapter and adapted to cooperate vwith shoulders on said member and said tube.

4. A work feeding device comprising a stock feeding member, an adapter insertlble Within said member, said adapter and said member having shoulders formed thereon to limit the movement of said adapter upon insertion within said member, and a feed tube rovided with means for securing said memr thereto and a shoulder for holding said adapter Within said member in assembled position.

JOSEPH M. BACIGALUPI.

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