Appeal from the District Court of the United States for the Eastern District of New York.
Before MANTON, SWAN, and AUGUSTUS N. HAND, Circuit Judges.
AUGUSTUS N. HAND, Circuit Judge.
This is a suit for the alleged infringement of United States letters patent No. 1,358,483, to Adolph Wachsman, for a stop mechanism particularly adapted for use on machines for knitting sweaters, hosiery, and similar articles. The device operates to close an electric circuit for the purpose of stopping the knitting machine whenever a knot or similar defect in the yarn coming from the bobbin stand exerts undue tension or pull, thereby actuating the stop device.
The specification states that the invention "embodies improvements in the spring connection for closing the circuit * * * in the means for regulating the tension on the actuating lever of the device, and in the efficient, short leverage whereby the lever and spring are brought into positive engagement without producing undue pressure on the spring."
The improvements shown in the patent comprise a boxlike support, to which is pivoted a switch lever having a slot. To the support there is secured a hooked member haning a depending nose normally extending through a slot in the lever. A leaf spring forms one terminal of an electric circuit which includes a magnet. The other terminal of the circuit is the knitting machine itself, which supports a disc to which a number of the stop devices are attached, one for each knitting machine. The yarn passes upward from the bobbin through an eye in a gauge plate, on over the lever, and then to the knitting machine. The lever is held in its upper position by a coiled spring, the tension of which is adjusted by a lever having a finger piece in engagement with one of a row of notches whereby the spring may be lengthened or contracted. When there is a knot in the yarn, it can no longer pass through the eye in the gauge plate. It, therefore, exerts an excess pull on the lever and moves it against the force of the spring. By the rotation of the lever upon its pivot, its inner end is brought against and contacts with a leaf spring to close the circuit. This energizes a magnet and operates a trip member of the knitting machine to stop it.
The claims in the patent are as follows:
"1. In a stop mechanism for knitting machines, a suitable support, a lever pivoted thereto provided with a slot, a hooked member having its nose or end normally extending through the slot, a source of electrical energy, an electromagnet, a trip actuatable thereby, and a leaf spring in circuit with the source of electrical energy and magnet and cooperating with the pivoted lever so that the latter may make and break the circuit depending on the position of the hooked member with reference to the slot in said lever, whereby, when the lever is in engagement with the spring, the electromagnet is energized and the trip actuated, and when the lever is disengaged from the spring the circuit is broken.
"2. In a stop mechanism for knitting machines, a suitable support, a lever pivoted thereto, a source of electrical energy, an electromagnet, a trip actuatable thereby and a leaf spring in circuit with the source of electric energy and magnet and cooperating with the pivoted lever, a spring having one end affixed to said pivoted lever and the other end secured to a second lever and means for adjusting the latter to vary the tension on the spring and the pivoted lever.
"3. In a stop mechanism for knitting machines, a suitable support, a lever pivoted thereto, a hooked member extending from the support and cooperating with the lever so as to normally form an inclosed space for the passage of the thread to a knitting machine, a source of electrical energy, an electromagnet, a trip actuatable thereby and a leaf spring in circuit with the source of electric energy and magnet and cooperating with the pivoted lever, a coiled spring for exerting tension on the lever, and a manually operated lever for regulating the tension on the spring."
The original claims of the patent were six in number, and were all rejected on United States patent No. 706,840 to Martin & Palmer and United States patent No. 808, 475 to Patterson, among others.
The amended claim 1 was allowed upon the contention of Wachsman that none of the references "show a lever provided with a slot and a hooked member cooperating with said slot." These features were embodied in the amended claim.
The amended claim 2 was allowed because Wachsman added to the original claim the element of "a second lever and means for adjusting the latter to vary the tension on the spring and the pivoted lever."
The amended claim 3 was allowed because of the addition of the words of the specific element, "a hooked member extending from the support and cooperating with the lever so as to normally form an inclosed space ...