US1387136A - John s - Google Patents

Description

J. S. FINCH.

POWER TRANSMITTER.

APPLICATION FILED JULY 25, 19H.

x w y y z w can ne states" Persistor es.

JOHN s. rmc'rr, or Bitineiirorvr, CO N CTICUT, AssieNoRro THE SINGER MANUL- I FACI'URING COMPANY, A CORPORATION: or NEW JERSEY I Application filed July 25,

TO. all whom it may concern Be it known thatl, J OHN S. F INCH, a citizen of the United States, residing at Bridgeport, in the county of Fair-field and State .of Connecticut, have inventedcertain new and useful Improvements in Power-Transmitters of which the following is a specifica- Applicant introduce into the present class of construcpresent invention. I

tion, reference being had therein to the ac- Icompany ng drawings.

=1 Ellis-invention relates to improvedmeans for arresting the transmission of power by the application of a, so termed, dash p.ot to an already existing :stop motion mechanism in such manner and having such .controlas to give to the main or driving shaft of a the operating of sewing machines for eflectmg a seam formation or for producing predetermined figures or designs, as in button sewing and eyelet and'buttonhole ov erseam-.

ing. a

is aware that it is notnewto tions the employment of a dash-pot, but it is believed that it has never been employed as herein to effect a stop action which is sub- 7 stantially automatic in meeting the requirements of changes in speedland comprising substantially the onlyymeans employed for frictionally resisting theaction of the machine after'the supply of power has been discontinued, in other words, as the resistance offered by. the a'ction of the dash-pot is automatically increasedor diminished substantially pro rata with the changes on the speed I given the machine, due to the corresponding change in the speed given the piston to compress the fluid in the cylinder chamber and I the latter directly conneotedwith the main shaft through a depressing member, there isI-effected an automatic control believed to V be new to its application to stop mechanisms.

Referring to the drawings, which form a part of the specification, Figure 1 is a View in front side elevation'of the rear end portion of a sewing machine equipped with the Fig. 2 is a view in elevation of the stop-mechanism oscillating frame provided with a dash-pot. Fig. 3 is a View in side elevation of Fig. 2 except that Specification of Letters Patent. Patented Au-g;

POW'ER TRANSM-ITTER.

1917. SeriaINo. 182,654. f

the dash-pot cylin der is shown'in section 7 Fig. 4:, is a view "in perspectiveof the pistonrod depresslng cam or member.

Stopm'echanisms of the gene t l character referred toherein arewell known in the art, one type similar to that-of 1thepresent'constructionfbeing' disclosed in the United States Patent to E. B. Alleng 'No. $743,213, dated November 3, 19031 As this invention 1n its present application'relatesto an im- 55 provement' in this classlof stop mechanisms,

only vsuch detai'lecl ieference'will be made theret'o as is deemed necessary. for ,a proper.v

understanding of-its application.

Referring to the figures, 1 represents the frame-base upon which-is" mounted the arm .bracket standard 2111a .3 th re mnd portion of said bracket. '4 denotes the nain or drive-shaft operatively connected by a' belt 15 with one form of commonly-employed 1 .ptaker actuating shaftjtnot shown), ,6 .a

drive shaft, a loose pulley. mounted upon the latter and 8 tight or} driving pulley provided with the flange ",9 carrying, the piston-rodl depressing eccentric; canuor member 10, r p

11 represe s the pis o d os illatin fr suspended, y oppo ly rrang d pivotal screws I @(one ,only" of which is shown), whic'h' latter'are threaded v into a "handrwheel suitably {secured upon said bracket 13 Isuitablysecured. to .thes al dard 2. 1i denotes. the" piston-rod mountedgin said frame for vertical noyement limited 'inits upward -stno'ke bylthehsuijtably secured collar 15, said rod carrying a t-its lower-Tend a p ston lfi of a chamelter slightl less than the inner diameter of the cylinder 117, the

stem l8 o-f which is threaded into the oscila lating:.-frame bearing-":19 and through which passesithe lower-end of said piston-rod, the vents, as 20, bemg provided lin the upper portion of the cylinder topermit' the escape I of the fluid; I

'21 represents the piston-rodspr ing interposed between the iupperend of the stem 18 and the collar 15 :and although the resiliency. of said spring causes the free end 22 of the piston rod to exert a slight retardation of the depressingcami its primary function is to effect a vertical. movement of thep'iston afterthe action of said'camon said-free end has compressed the a'ir'in the cylinder.

In the present construction, ,as in the con-. struction of the patentpreviously" referred to, manual means are employed for effecting the starting of the machine and means for automatically discontinuing such action which may be as shown and described in said patent and as partly herein shown, or of any other approved form of control as the present invention may be employed in connection with manually controlled means only, as in stitching seams of undetermined length, and, accordingly, the present reference to such combined automatic and manual control will be limited to such primary elements as are more directly connected with the stop-mechanism.

nected with the frame arm 29 carried by the oscillating frame 11. 30 denotes a frame retaining arm carried by said frame whose upper end is provided with a catch-lever screw 31 threaded into said retaining arm, said screw cooperating with a latch 32 carried by a catch-lever 33 suitably secured upon a shaft 34 journaled in suitable bearings '(not shown) in the standard 2.

85 represents a trip-lever carried by the shaft 34 whose free end cooperates with a flange 36 of a slidably mounted sleeve 37 carried by the main shaft, said sleeve being automatically controlled by common means (not shown) to move in the direction of the length of said main shaft and trip said latch out of engagement with the screw 31 and permit the spring 88 to rock the frame 11 andcarry the free end 22 of the pistonrod in alinement with the cam-surface 23 of the cam 10, which latter, in its rotation, forces said rod downward in opposition to the resistance offered by the air being compressed in the cylinder until the free end 22 enters the stop-notch 39 in the depressing cam, when the machine is brought to rest. It is to be understood, however, that vthe present invention is not limited to the particular form of tripping means 35 referred to, as any well known device of this nature may be employed to trip the oscillating frame 11, such a device being disclosed, for

instance, in the Allen U. S. Patent No. 748,213, hereinbefore referred to. To start the machine the frame 11 is rocked, by actuating the pedal rod 25 previously referred to, in the opposite direction until the latch 22 engages the catch-lever screw 31, it being understood that the driving belt (not shown) is shifted by the belt-shifter 40 from loose to tight pulleyand vice versa by the rocking movements of said frame.

As the clearance between piston and cylin der is fixed it follows that the pressure of the air under the piston or, in other words, resistance against its movement is proportional to the speed of the piston. In the mechanism described above the cylinder and piston form a brake for the moving mecha nism and the braking power is proportional to the speed of the mechanism The momentum of the mechanism, however, is proportional to the square of the speed, but it has been observed that in constructions of the present nature the increased friction due to increased speed is such that the braking power required to bring the mechanism to a standstill is very nearly proportional to the speed of the mechanism, so that, the present arrangement of piston and cylinder furnishes the kind of brake required for the given conditions.

Having thus set forth the nature of the invention, what I claim herein is 1. In a stopmechanism, the'combination with a driving shaft and'means for rotating the same, of cooperating elements operating i it in one direction for frictionally retarding the rotation of said shaft witha braking effect varying proportionally with the speed of rotation of the shaft and operating subsequently in a direction substantially transversely to said first mentioned direction to arrest the rotation of the shaft.

2. In a stop-mechanism, the combination with a rotating shaft and means for rotating the same, of a depressing member carried by said shaft, a fluid compressing dash-pot including a piston-rod, means for throwing saidpiston-rod into frictional engagement with said depressing member to actuate the piston-rod longitudinally and retard therotation of the shaft with a braking effect varying substantially as the speed of rotation, and a stop-element adapted to laterally engage said piston-rod to arrest the rotation of the shaft. 7

3. In a stop-mechanism, the combination with a drive shaft and means for rotating the latter, of means for arresting the action of said shaft comprising a depressing mem- 7 her carried by said shaft, an oscillating frame, a dash-pot with its piston-rod carried by said oscillating frame, means for holding said piston-rod out of engagement with said depressing member during the normal rotation of said shaft, and means for releasing said holding means whereby said oscillating frame is locked to position said piston-rod in the path of said depressing member to frictionally retard the rotation of said drivingshaft with a braking effect varying proportionally with the speed of rotation, and

means coacting with said piston=rod for subsequently arresting the rotation of said shaft.

4. In a stop-mechanism, the combination with a drive shaft and means for rotating the latter, of means for arresting the action of said shaft including a depressing member provided with a stop-notch a dash-pot, a piston-rod, and a piston-rod spring, said depressing member acting on said piston-rod to cause the resilient action of said spring ,and dash-pot to retard the action of said drive shaft until the resiliency of said spring acts to set the free end of said piston-rod in said notch to arrestthe action of said driveshaft.

5. In a stop-mechanism, the combination with a drive shaft and means for rotating the latter, of means for arresting the action of said shaft including a'depressing member provided with a stop-notch, an oscillating frame, a dash-pot, a piston-rod, and a pistonrod spring carried by said oscillating frame, said depressing member acting on said piston-rod to cause the resilient action-of said spring and dash-pot to retard the action of said drive-shaft until the resiliency of said spring acts to set the free end of said piston-rod in said notch to arrest the action of said drive-shaft.

In testimony whereof, I have signed my name to this specification.

JOHN s. rmcri.

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