US403217A - Mechanical movement - Google Patents

Description

IF. H. RICHARDS. MECHANICAL MGVEMENT.

No. 403 217. A Patented May 14, 1889..

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@wimm Smmro@ NITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO l DAR-IEN W. DCDSON, OF VVILKES-BARRE, PENNSYLVANIA.

MEoHANlcAL MOVEMENT.

SPECIFICATION forming part of Letters Patent No. 403,217, dated May 14, 1889. Application filed December 18, 1886. Renewed May Z, 1888. Serial No. 272,538. (No model.)

.To all whom may concern.'

Be it known that I, FRANoIs H. RICHARDS, a citizen of the United States, residing at Springfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful Improvements in Mechanical Movements, of which the following is a specification.

This invention relates to that class of mechanical movements which includes the one described and claimed in my application, Serial No. 218,973; and the present invention consists in certain improvements in the latch mechanism which forms a part of the subject-matter of my said prior application, as hereinafter more fully set forth.

In the drawings accompanying and forming a part of this specification, Figure 1 is a plan view of so much of a mechanical Inovement of the class specied as embodies my present invention. Fig. 2 is a sectional side elevation of the latch and key mechanism of the same, showing the latch set ready for use. Figs. 3, 4, and 5 are similar views illustrating the mode of operation of the parts shown in Fig. 2.

Similar characters designate like parts in all the figures.

The frame work A, ofany preferred construction adapted to carry the mechanism, has a stud or shaft,D, on which turns a revoluble frame or turret, II, that carries the shaft 6, having thereon the starting-arm 26. Said frame also has formed therein a suitable bearing for a reciprocating latch, 50, which is thrown forward (toward the left hand, as

hshown in the drawings) by a spring, 52, acting through rod 53 against projection 54 formed on said latch, a suitable stop, as 55, being provided to properly limit the forward movement of the latch. The object, construction, and mode of operation of these-several parts are full described in my aforesaid application, Serial No. 218,973, to which reference may be had.

According to my present invention, the latch 50 has pivoted thereto, at 3, a latchpawl, 4, arranged to engage with a notch or corner, as 5. on frame A. Said pawl may be so constructed as to operate by gravity; but

I prefer to use some sort of spring, as 2, to normally hold the pawl in the position shown in Figs. 2, 4, and 5. For operating it to unhook the latch, said pawl has a projecting arm or lever, 7, adapted to be struck by a similar part of a latch-tripping device. This device comprises a carrier having a movement (usually a sliding one, as shown) crosswise to the movement of latch 50, a key and return-spring operating said carrier, a snap pawl or catch on the carrier and operating the latch-pawl, and preferably a detent resisting the first movement of said carrier.

In their preferred form those several parts are constructed and arranged as follows: The carrier consists of a vertical spindle or slide, 10, whose lower end, l1, iits freely in a bearing in frame A, and whose upper end, 13, fits, freely within the verticallysliding key l2, which key has its bearing in frame A. Said spindle is supposed to be kept from rotating by a key or spline, or other means. (Not shown.) It has a pin, 14, working in slot lof'key 12, (or some device equivalent to these, but not shown,) for regulating the relativefstrokes of itself and said key, is constructed to carry the snap-pawl, and has a detent-arm, 16, formed thereon. Said arm normally rests on the beveled or inclined detent-notch 17 of the detent-spring 18, as in Figs. 2 and 5; but on the first downward movement of the carrier the detent-spring is forced back, as in Figs. 3 and 4, and no longer materially resists the further downward movement of said carrier.

The snap-pawl consists of an arm or lever, as 20, pivoted to (or in) the carrier at 21, and limited ,in its upward movement by stop 19. This pawl is or may be normally held in place (with its point directly over arm 7) yby pullspring 22, connected to arm 23 of the pawl and to the carrier at 24. A push-spring, 25, serves to uplift the carrier and key, and another similar spring, 28, intermediate to said carrier and key, transmits motion from the key 12 to the carrier.

The operation of this apparatus is as follows: The latch being hooked back, and the other parts standing as in Fig. 2, the operator presses down key 12, as in Fig. 3, or until .by the compression of spring 28 sufficient force IOO is exerted on slide 10 to drive back detent 18, and thus allow said spring 2G to instantly complete the downward movement of said slide, as also shown in 3. This downward movement is suflicient to carry pawl 20 against and past arm 7 of pawl 4, thereby unhooking said pawl and permitting the latch to be thrown forward, (toward the left hand,) as in Fig. Suppose, now, that the arm 2G immediately returns latch 50, and that this is hooked back, as in Fig. 4f, the carrier being still down, as there shown. The arm 2O will then stand beneath arm 7, and will on the upward return movement of the carrier turn on its pivot 21 and thereby escape interference, as illustrated in Fig. 5. If the carrier could always be allowed to return before the return of the latch, it is evident the arm 2O could then be integral with said carrier; but in practice this is rarely possible, and never to be relied on, since the latch moves very quickly, so that its outward and return strokes together occupy only a very small fraction of a secoiidwsoinetimes less than the fiftieth part thereof.

To the extreme rapidity of movement of the latch is due the utility of the detent device in the combinations shown, for unless the downward movement of arm 2O is itself very sudden this arm may not pass down far enough and rapidly enough to escape the arm 7 of the returning latch-pawl 4c; but the detent device insures that the movement when once begun shall be instantly completed.

It will be understood that this latch mechanism is capable of modification in various ways and degrees, after the manner of machines in general, within the scope and limits of my invention.

This latch mechanism is applicable as a 4o wheel-starting apparatus to typewriters of the general class which includes the typewriter described in United States Patent No. 299,751, granted to D. W'. Dodson, June 3, 1884-that is to say, to type-writers whose types or type-wheels have independent orbital and axial rotary movements.

Having thus described my invention, I claimi 1. The combination, in a latch mechanism of the class described, of the latch carryinga pawl that terminates in an arm wherebyit is operated, a carrier having a movement crosswise to the latch-movement, and an arm projecting from said carrier, to strike and unhook said pawl, said carrier being operated from a key, all substantially as set forth.

2. The combination of the latch and its pawl, a carrier having` a snap-pawl, 20, a detent resisting` the first movement of said carrier, and a key and springs operating in connection with the detent to :impart a sudden movement to said carrier, all substantially as set forth.

3. The combination of a reciprocating carrier having a detent-arm, a spring having a corresponding detent-notch, a key, and a spring intermediate to said key and carrier, all operating substantially as and for the purpose set forth.

4. The combination of carrier 10, having arm 1G, spring' 18, having notch 17, spring 25, key 12, and spring 2S, all constructed and operating substantially as shown and described.

FRANCIS H. RICHARDS.

lVitnesses:

WIL'BUR M. STONE, DAMEN W. DoDsoN.

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