Cushman Chuck Co. v. Whiton Machine Co.

170 F. Supp. 815, 120 U.S.P.Q. (BNA) 258, 1956 U.S. Dist. LEXIS 2207
District Court, D. Connecticut·Decided May 25, 1956·No. Civ. No. 4679·Published

Opinion

J. JOSEPH SMITH, Chief Judge.

This is an action for infringement of a Schuster U. S. patent No. 2,401,971 on a device called by plaintiff its “Accro-matic” power chuck. The defenses are invalidity and noninfringement. Both plaintiff’s device and the accused device of the defendant, an embodiment of Highberg patent No. 2,687,308, have as their principal advance over others in the art means for fine adjustment of individual jaws of a multi jaw power chuck to obtain precise centering of the workpiece or tool held by the chuck during machining operations. A chuck is a holding device, in its simpler forms similar to the holding device which grips the bit in the familiar carpenter’s brace and bit. A power chuck is one in which the gripping pressure of the jaws is furnished by pneumatic or other power. Prior to the development of the devices in suit a standard form of power chuck with multiple jaws was the step by step American Standard form, in which each master jaw to which the power was applied had attached to it a work-gripping false jaw which could be moved relative to the master jaw toward or away from the work-piece in steps along a series of teeth and grooves, on the surfaces of the two jaws which engaged each other, at right angles to the direction of movement toward and away from the work-piece, the false jaw being firmly attached to the master jaw by bolts when the desired step was reached. No provision was made for fine adjustment within the steps, that result apparently being obtained by machining of the faces of one or more of the work-holding or false jaws.

Between-step adjustment by screw type mechanism is revealed by an earlier patent. It is probably true, however, that there is more play and more difficulty in setting to fine adjustment the screw type device than the transverse wedge or cam action of the devices in suit.

There is little convincing evidence of the extent of the need in the trade of the fine adjustment by other means than machining of jaw faces or the saving in time and expense by eliminating that necessity. The evidence developed the curious fact that the Accrolock device as furnished the trade in practice failed to provide fine adjustment through the full distance between steps, although when this was pointed out it proved a simple matter to modify the device and provide the full range.

Methods of providing movements by very small increments of parts of devices, in other fields, similar or equivalent to [816] the cam or wedge action used in these chucks are demonstrated to be old, as is usual in combination patents.

Was their use here merely an answer which would have occurred to any good mechanic skilled in the art faced with the problem, or did it require something more which can be called invention ? Both devices in suit have apparently enjoyed some degree of commercial success. The ideas which make up the elements of the claims are found in the prior art. The question is whether the combination of them to obtain the device of the claims required “invention”. That the combination was not easy to come by may be argued from several facts, most important perhaps that before Schuster fine adjustments were normally obtained by machining one or more jaws in place in the chuck — an obviously cumbersome method of adjustment. Other bits of proof of the desirability of such an advance are plaintiff’s willingness to buy out the patent owner’s entire operation to obtain the patent, the apparently substantial demand for chucks embodying in part at least the advantages of the patent, and the prompt development and adoption of the accused Highberg device by defendant after Highberg, who had been instrumental in plaintiff’s acquisition of the Schuster patent, went from plaintiff’s to defendant’s employ.

It is true that independent jaw adjustment in a universal chuck had been provided before Schuster, by screw adjustable means. Those devices, however, were not a solution of the problem for two reasons, the coarser adjustment provided by the direct screw action, and the play in the mechanism soon caused by the fact that the gripping pressures were applied directly through the screw. Prior to Schuster, the trade still largely depended on step by step adjustment through the American Standard jaws, with fine adjustment where necessary by machining of one or more jaw faces in place in the chuck. Forkhardt had provided both step by step and screw activated (indirect) fine adjustment of multiple jaws, but the fine adjustment was universal only, not independent.

Independent individual adjustment of the top jaw was not new, screw type mechanism having been employed for that purpose, according to plaintiff’s expert Johnson.

What was new was the accomplishment of fine independent individual adjustment by transverse movement of the key having splines engaged with serrations in the master jaw. As far as we recall, none of the screw type individually adjustable top jaws was on a serráted jaw type chuck.

Whiton’s structure — the Highberg et al. patent — applies an idea similar to Cushman’s, by a different construction, to the American Standard master jaw with straight transverse teeth.

Forkhardt has the screw activated angular rack to impart radial motion universally to the jaws — not for one jaw independently of the other, but the device to obtain the radial motion was familiar in the trade. Schuster applied it to the problem of obtaining fine independent adjustments of the false jaw — ■ Highberg adapted similarly the American Standard by a somewhat equivalent device.

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Cushman Chuck Co. v. Whiton Machine Co., 170 F. Supp. 815, 120 U.S.P.Q. (BNA) 258, 1956 U.S. Dist. LEXIS 2207 (D. Conn. 1956).

170 F. Supp. 815 (Cushman Chuck Co. v. Whiton Machine Co.) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.