Warner Instrument Co. v. Stewart & Clark Mfg. Co.

185 F. 507, 107 C.C.A. 607, 1911 U.S. App. LEXIS 4021
CourtCourt of Appeals for the Seventh Circuit
DecidedJanuary 3, 1911
DocketNo. 1,716
StatusPublished
Cited by2 cases

This text of 185 F. 507 (Warner Instrument Co. v. Stewart & Clark Mfg. Co.) is published on Counsel Stack Legal Research, covering Court of Appeals for the Seventh Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Warner Instrument Co. v. Stewart & Clark Mfg. Co., 185 F. 507, 107 C.C.A. 607, 1911 U.S. App. LEXIS 4021 (7th Cir. 1911).

Opinion

CARPENTER, District Judge.

This suit was brought by the appellant to restrain the infringement of patent No. 837,188, issued to A. B. Cadman November 27, 1906, for an invention “in drive-gearing for automobile speed indicating mechanism.” At the final hearing-in the Circuit Court, where the bill was dismissed for want of equity, the complainant limited his prayer for relief to claims 9, 10, and 11, as set forth in his application. These claims are as follows:

“9. The combination with a wheel having a gear, a pivotally-mounted steering-knuelde upon which said wheel is journaled to rotate, drive-gearing mounted upon said steering-knuckle and arranged to be driven by the gear on said wheel, a transmitting-shaft driven by said drive-gearing, and con[508]*508nections between said transmitting-sliaft and said drive-gearing, whereby said drive-gearing may partake of the rocking or swinging movement of the steering-knuckle without bending or twisting said transmitting-shaft.
“10. The combination with a wheel having a gear, a pivotally-mounted steering-knuckle upon which said shaft is journaled to rotate, drive-gearing mounted upon said steering-knuckle and arranged to be driven by the gear on said wheel, a transmitting-shaft arranged to be driven by said drive-gearing, a sheathing for said transmitting-shaft, and connections for permitting said drive-gearing to partake of the rocking or swinging movements of the steering-kuuclde without transmitting the same to said sheathing.
“11. The combination with a wheel having a gear, a pivotally-mounted steering-knuckle upon which said wheel is journaled, a gear-casing carried by said steering-knuckle, drive-gearing arranged within said casing and adapted to be driven by the gear on said wheel, a transmitting-shaft arranged to be driven by said drive-gearing, a sheathing for said transmitting-shaft, and connections between said sheathing and casing to permit the latter to partake of the rocking or swinging movement of the knuckle without transmitting such movement to said sheathing.”

The development of the automobile has brought with it a train of accessories, the manufacture of which has become an important part of the industrial activity of this country. Among these is the speed indicator. Experience has shown that it is necessary to operate automobile speed indicating devices through gear connections from one of the front wheels of the vehicle. The front wheels ordinarily are not power driven, receiving their rotary movement through friction with the ground, and consequently are not subjected to the slipping of the power-driven wheels which often occurs when starting up with a heavy load, or on wet or greasy streets, or when the brakes are applied. The slipping of the shaft or wheel which drives the speed indicator naturally renders the reading of the instrument inaccurate. This indicator is mounted inside the car, at some point where it can be observed readily by the driver, and usually is operated by mounting a gear-wheel on the front 'wheel of the vehicle concentric with the axis of the stub axle‘about which the wheel turns. With this gear-wheel there meshes a pinion, carried by a mount supported on the steering-knuckle in such relation as to maintain always the pinion and gear-wheel in mesh with each other, notwithstanding the rocking or swinging movements of the knuckle, resulting from_ steering the machine. The pinion is connected through a flexible shaft with the speed indicator.' It becomes necessary, with this arrangement, to accommodate the rocking or swinging movement of the front wheels in steering the machine without impairing the proper drive connection of the gearing which transmits the rotary movement of the wheel to the- speed indicator'.

As a result of the constant swinging or rocking movement of the steering-wheel, the flexible .shaft leading to the indicator on the car becomes bent back and forth. This bending causes a crystallization and rapid wearing out or a breaking of the shaft or its protecting sheath.

The first means devised to obviate this difficulty was to reinforce the sheathing, probably because reinforcement was cheaper than any other method; but this, it seems, did not suffice, although at the present time many speedometers are connected with the wheel by means of a straight drive flexible shaft with the reinforced sheath.

[509]*509In this state of the art, Cadman, as appears from the specifications in his patent, sought “to provide a drive-gearing of such construction and arrangement as to enable the steering-knuckle to be rocked or swung in the steering of the car without imparting to the transmitting-síiaft a twist or turn, or without subjecting the protecting sheathing therefor to undue rubbing, chafing or wear, thereby avoiding any possibility of inaccuracy in the reading of the instrument through the bending or twisting of its driving-shaft, and also avoiding rapid wear upon the protecting sheathing of such shaft.”

It will be unnecessary to consider in detail the drawings and specifications of the inventor to determine how he intended to carry out his idea. Counsel for appellant, in his original brief, states:

“It will be seen that the feature which in the operation of the device, and in its association and co-operative relation with respect to the other parts of the device, effects the desired objects and purposes of the inventor, and which overcomes the defects and objections of the prior devices, is the swivel-joint connection of the, flexible shaft 'Which drives the, speed indicator. with a drive-gearing so mounted and arranged upon and with reference to the steering-knuckle, the steering-wheel, and associated parts that the steering-knuckle may freely rock or swing to accomplish the steering of the machine without imparting any material coincident bends to the flexible sha ft.”

The swivel-joint connection on a power shaft is an old device. As early as January 18, 1870, patent No. 98,864 was issued to G. F. Green, wherein it appears that the object of his invention was “to construct a universal joint which will he capable of transmitting motion from a driving shaft in any combination of machinery, at any desired angle, and which may either be set or held in any position, or allowed to change the angle while in motion, as the case may require.” Since that time a number of patents have issued for improvements on such universal joints. Similar devices have been used with flexible shafts on dental engines, horse clipping machines, sheep shearing machines, and a great many other mechanical contrivances, and the flexible joint in all of these performs exactly the same function that it performs in the Cadman patent.

The problem which confronted the trade in connection with the speedometer was how to transmit the power from the steering-wheel to the speed indicator without a swinging or rocking motion being given to the flexible shaft whenever the steering-wheel was turned from side to side.

This problem involved the transmission of power from a rocking-wheel to a stationary indicator. The problem which was met in the case of the dental machines and the shearing machines was the transmission of power from a stationary source to a moving operating point. Clearly it did not require inventive genius to transfer the universal or swivel joint from one end of the shaft to the other.

It is admitted by the appellant that the operation of speedometers by means of a flexible shaft is not new, but it is claimed that:

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Bluebook (online)
185 F. 507, 107 C.C.A. 607, 1911 U.S. App. LEXIS 4021, Counsel Stack Legal Research, https://law.counselstack.com/opinion/warner-instrument-co-v-stewart-clark-mfg-co-ca7-1911.