Hartshorn v. Almy

11 F. Cas. 708, 2 Ban. & A. 46
U.S. Circuit Court for the District of Massachusetts·Decided April 15, 1875·Published

Opinion

SHEPLEY, Circuit Judge.

The bill in this case is brought for alleged infringement of reissued letters-patent No. 2,756, dated Aug. 27, 1807, granted to Stewart Hartshorn for improvement in spring-fixtures for shades.

The claim is for the application to a shade-roller, provided with a spiral spring for automatically raising or rolling up the shade, of a pawl and ratchet, or notched hub, so arranged that the former will engage with the latter at any point or height of the shade, by simply cheeking the rotation of the roller and the upward movement of the shade under the influence of the spring, substantially as set forth.

Upon the construction of this claim depends the question of infringement in this case. Defendants contend for a construction which will limit the claim to the peculiarly shaped pawl and the peculiarly shaped ratchet described in the specification of the patent. Complainant contends for a construction which will embrace, in combination with the other elements, any pawl and ratchet, or notched hub, so arranged that the former will engage with the latter at any point or height of the shade by simply checking the rotation of the roller and the upward movement of the shade under the influence of the spring, substantially as set forth.

The state of the art before the invention of Hartshorn was this: A roller was used having within it a coiled spring, one end fixed to the roller and the other end to a loose journal of the roller; a pawl and ratchet were so applied to the roller that the pawl would hold the roller against turning under the action of the spring,’ but allow the roller to be turned against the action of the spring. The ratchet lifted and disengaged the pawl from the ratchet in a downward pull of the curtain. These rollers were adapted, like the Harts-horn, to be hung in brackets. In the form of spring-fixtures for shades which was known as “the Coach fixture,” and in use prior to-Hartshorn's invention, a cord was used to lift the pawl and disengage it from the ratchet when it was desired to allow the curtain to roll up under the action of the spring. Hartshorn’s invention differed from those which had preceded it in that it dispensed [709] with the cord used to disengage the pawl from the ratchet when the curtain is to be rolled up, and operated the fixture wholly by means of the shade or «curtain. The operation of Hartshorn’s fixture, so far as concerns winding up the curtain tmd stopping it at any desired height, is as follows: A pawl is attached by a pivot to one of the brackets in which the shade-roller is hung. The end of the pawl opposite the pivoted end has a tendency to fall by gravity on a hub attached to one end of the roller. Two notches are made in the periphery of this hub. The width of these notches is but slightly in excess of the width of the toe of the pawl. The ratchet supports the pawl for the full extent of its periphery, except as to the slight difference in excess between the width of the ratchet notch and the width of the toe of the pawl. Should the roller be revolving rapidly, the width of the ratchet notch will pass under the width of the toe of the pawl before the toe of the pawl has had sufficient time to gravitate into the ratchet notch. This space of time is very short, for it is only while the excess of width between the width of the notch and the width of the toe of the pawl is passing under the toe of the pawl. This only allows the pawl toe to gravitate into and engage with the ratchet notch under a slow movement of the roller. Under a quick revolution of the roller the pawl toe will not be unsupported by the periphery of the ratchet for a space of time sufficiently long to allow it to gravitate a sufficient distance into the ratchet notch to become engaged with it while the ratchet notch is passing under it. The patentee also states that, if desired, the pawl may be placed- underneath or at one side of the hub instead of over it, as represented, and a spring be made to bear against it, in order that its projection may engage with the notches.

It will thus be seen that the invention of Hartshorn consisted (so far as concerned the spring-roller shade-fixture) in dispensing with the weights, counterpoises, and pulleys, which had been previously employed, and also with the cord which had been employed to operate the pawl'and disengage it from the ratchet notch, and so arranging, the pawl and ratchet that the shade may be stopped and retained at any desired point within the scope of its movement by a simple manipulation of the shade itself; the arrangement of the pawl and ratchet being such that the former will engage with the latter at any point by simply checking the rotation of the roller and the upward movement of the shade under the influence of the spring.

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Hartshorn v. Almy, 11 F. Cas. 708, 2 Ban. & A. 46 (circtdma 1875).

11 F. Cas. 708 (Hartshorn v. Almy) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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18 F. 90 (U.S. Circuit Court for the District of Massachusetts, 1883)