US1477699A - Stop mechanism - Google Patents

Description

Dec. 18, 1923. 1,477,699

A. B. FOWLER sToP MECHANISM med Feb. 5; 1919 2 sheets-sheer;

Wfes. @MC @m0,

Dec, 18,1923. A. B. FowLER sToP MEQHANISM EiledFeb. 5. 1919 2 Sheets-Sheet 2 [r2 Ven im .WZz'ess l @MCG/ww afl/MMM Patented Dec. 18, 1923 .ALFRED B. FOWLER, F BEVERLY,

tame

PATENT OFICE.

MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHINERY CORPORATION, OF PATEK-SON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

savor MECHANISM.

Application led February 3, 1919.

.To all whom it may concern.'

Be it known that I, ALFRED B. FowLnR, a citizen of the United States, residing at Beverly, in the county of Essex and State of assachusetts, have invented certain new and useful Improvements in Stop Mechanisms; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will ena-ble others skilled in the art to which it appertains to make and use the same.

The present invention relates to mechanisms for stopping a machine with the driven parts in a predetermined position.

One of the objects of the invention is to provide 'a novel and improved stop mechanism which is especially adapted for use in machines wherein it is desirable to render certain parts or devices thereof active for a predetermined interval in the final cycle of operations. A machine of this type is the inseam shoe sewing machine illustrated and described in applicants copendingl application, Serial No. 254,104, filed Sept. 14C, 1918,

wherein thread cutting and holding devices are employed that are rendered active for a predetermined interval in the final cycle of operations of the machine.

To this end a feature of the invention contemplates the provision of means under the control of the operator for throwing out the driving mechanism of a machine at a predetermined point in a. cycle of operations, and means for stopping the rotation of the driven parts of the machine a predetermined interval after the drivingV mechanism is thrown out. In the preferred embodiment of the invention, after the driving mechanism vis thrown out the machine is driven by its own momentum for a predetermined interval before the means for stopping the machine is rendered active, but this specic mode of operation is not essential to the broader features of the invention.

Another object of the invention `is to provide-a novel and improved mechanism which will operate `efficiently and uniformly in Serial No. 274,608.

stopping the driven parts of machine irrespectl've of the speed thereof when the mechanism comes int-o action- To this end the invention contemplates the provision of means under the control of the operator for throwing out the driving mechanism of a machine at a point in a cycle of operations dependent upon the speed of the machine.

@ther features of the invention consist in certain constructions, combinations and arrangements of parts hereafter described and claimed, the advantages of which will be obvious tot-hose skilled in the art.

The several features of the present invention will be understood from the following detailed description and the accompanying drawings in which:

Figure 1 is a vertical longitudinal section through a stop mechanism embodying the features of the present invention in their preferred form; Fig. 2 is a transverse vertical section taken on the line 2-2 of F ig. 1.

In the drawings, the' invention is shown embodied in a mechanism for driving and stopping a shaft 6 from which the operating mechanism of a sewing or other machine may be driven. The shaft 6 is driven by means of a friction clutch face 8, formed on a clutch member 10 that is splined on the shaft, when this clutch face is in engagement with a clut-ch face 12 on the interior of a driving pulley 14, as shown in Fig. 1. This driving pulley is mounted to turn loosely on a fixed bushing 16 surrounding` the shaft and is provided with a hub 18 adapted to engage a roll thrust bearing 20 when the driving pulley is forced sulhciently toward the right by engagement of the clutch faces 8 and 12. The clutch member 10 is provided with a grooved collar 22 that is engaged by a clutch shifting yoke 24 pinned on a horizontal rock shaft 26. The shaft 26 has a horizontally extending arm 28 secured to one end thereof` which is connected to a treadle 29 by a rod 33. By depressing the arm 28 by means of the treadle 29 and rod 33 the clutch eration of tlie'latch member l is shifted to the right to engage the clutch faces 8 and l2 and When the arm` 28 is released by removing the pressure on the treadle 29. al spring 35 acting on the arm 28 through the rod tends to more the clutch member l0 to the left to bring a friction brake face 30 on the clutch member into engagement with a cooperating face on the frame of the machine.

After the release of the arm 28, the movement of the clutch member is controlled by two cams, both of ,vhichare formed on a disk 32 which is mounted on the shaft 6. When the arm v28 is depressed to bring the driving clutch faces into engagement, a proiection 44 on the rock shaft 26 is movedupivardly, so that a lug 46 on the Vdependent arm of 'a latch lever 48, pivoted at 50, is dravvn beneath the lug by a spring 52 attached to the louerv end of the latch lever. This latch lever locks the rock shaft against asufficient backward movement to entirely disengage the `driving clutch faces. The latch lever 48 is engaged by one of the cams on the disk 32 during each revolution of the shaft 6, so that at a certain point in each cycle of operations of the'inachine, the rock shaft 26 is released and, unless held by the operator, through the medium of the i arm 28, can move in a direction to disengage the driving clutch faces. rThis cam is 1ndicated at 54. While the machine is running there is sufiicient play between the lug 46 on the latch lever 48 and the lug 44 on the rock shaft to alloiv the driving clutch to lbe so controlled by the operator through the arm 28 as to vary the speed of the shaft 6. `llihen the operator releases the arm 28, the spring connected therewith rocks the shaft 26 so that thelug 44 engages the lug 46,V but at this time there is sufficient friction exerted Ybetween the driving clutch faces to drive the shaft 6 until the latch lever is operated by the cam Such oplever releases the rock shaft 26 and allows the clutch member l0 to move further towards the left, so as to entirely disengage the driving clutch faces. The shaft 6 now continues to rotate under its own momentum. VI-rt this time the braking surface 36 is held out lof. engagement with the cooperating srufa'ce 3ion the frame by means of the second cam 56 on the disk 32,' which cani is enga-ged by a. roll 58 on the'upperV end of an arm 60 adjustably but rigidly fixed on the clutch operating'yofke 24. predetermined number of degrees of rotation' after the cam 54 has operated to rel-ease 'the latch throughthe lever 48, the cani56 allovv's the clutchmember l0 to move sojasto bringthe braking surface against the' cooperating braking surface frame ofthe machine and stop the shaft.

iA. 'coiled spring 62 surrounds a hub of the driving pulley 14 and is interposed be- ?il. on the l tween the iveb of the pulley and the thrust bearing 20.V The function of this spring is to keep the driving clutch faces in engagement after the operator releases the treadle and until the latch' lever 48 is operated. T he movement of the driving pulley to the left under the action of the spring 62 is limited byra stop collar 63 on the shaft 6.

it is evident that the duration of the period of. engagement of the braking surface-s 36 and before the shaft 6 is brought to rest is dependent lupon the speed of the shaft Wien the engagement of the braking surfaces is initiated. Accordingly, in order to stop the shaft at a uniform or definite point in its.V rotation, the start of the period of eny agement ofthe braking surfaces must occur at a point in the rotation of the shaft dependent upon the speed thereof at this time. To this end, in the illustrated 'machine, means are provided to vary the timing ofV the-cams 54 and 56 in accordance vvith thespeed of the shaft, which cams control the engagement of the braking surfaces as hereinbc'fereA described. The ca 32, which carries the cams 54 and is loosely mounted on" the shaft 6 and its position on the shaft is determined by tivo centrifugal governor arms 64 pivoted on studs 66 that project from a hand wheel 68 secured to one end of the shaft 6. The free ends of the governor arms z64 are connected by links 70 to the cam disk 32. The governor arms ar-e acted upon by springs 72 which tend to saving them inwardly; By means of this construction, the governor arms by centrifugal action Will advance the cam disk 32 cireumferentially of the shaft 6,'and consequently will time the start of the engagement of the braking surfaces in accordance With the speed of the shaft so that the shaft will be uniformly stopped at a predetermined point in' its rotation irrespective of ping mechanisn'i is'throvvn in.

lhile it preferred to employ the construction and arrangement of parts shown and described, it Will be understood that this construction and arrangement is` not essential except'so far as' specified in the appended claims.

1ilVhat is claimed as nen7 is l. A stop mechanism having, in combination, a driven member,A adriving mechanism therefor, means underl the control of the operator for throwing out the driving mechanism at a. point in the rotation of the driven member dependent upon the speed of' the driven member, and means for stopping the rotation of the driven member after 1 the driving mechanism is'thrown out.

`2. A stopV mechanism ha ring, in :combination, a driven member, driving mechanism therefor, means for stopping the rotation of the driven member after the driving mechm disk the speed thereof when the stoplil() il U vdri ven member anism is thrown out, and means under the control of the operator and timed by the for throwing out the driving mechanism a substantial interval before the driven member is stopped'.

3. A. stop mechanism' having, in combination, a driven member, driving mechanism therefor, means under the control of the operator and timed by the driven member for throwing out the driving mechanism at a point in the rotation of the driven member, and means for stopping the rotation of the driven member rendered active a predetermined degree of rotation after the driving mechanism is thrown out.

et. A stop mechanism having, in combination, a driven member, driving mechanism therefor, means controlled by the speed of the driven member for throwing out the driving mechanism, and means for stopping the driven member rendered active a predete-rmined driving mechanism is thrown out.

5. stop mechanism having, in combination, a shaft, a driving mechanism therefor, a brake for reducing the speed of the shaft, means for applying the brake, and means including a cam forvthrowing out the driving mechanism and for varying the timing l of the application of the brake in accordanceI with the speed of the shaft.

6., A stop mechanism having, in combination, a driven member, a driving mechanism therefor, means under the control of the operator and timed by the driven member for throwing` out the driving mechanism at a point in the rotation of the driven member, and cam controlled means for stopping the rotation of the driven member rendered active a predetermined degree of rotation after the driving mechanism is thrown out.

7. A stop mechanism having, in combination, a driven member', a driving mechanism therefor, means comprising a cam for throwing out the driving mechanism, means for varying the timing of the cam in accordance with the speed of the driven member, and means for stopping the rotation of the driven member after the driving mechanism is thrown out.

S. A stop mechanism having, in combination, a driven member, a driving mechanism therefor, al brake for reducing the speed of the driven member, means controlled by the speed of the driven member for throwing` out the driving mechanism, and means for applying the brake a predetermined degree of rotation after the driving` mechanism is thrown out.

9. A stop mechanism having, in combination. a driven member, driving mechanism therefor, means for throwing out the driving mechanism whereupon the driven member is actuated by its own momentum, a

degree of rotation after the braise for the driven member, and means for appiyinqthe brake at the completion of a predetermined degree of rotation of the driven member by its own momentum.

10,32L stop mechanism having, in combination, a driven shaft, speed reducing mechanism therefor, a cam forfcontrolling thc effective operation of the speed reducing mechanism, and a second cam mounted on the shaft for rendering the operation of said first cam effective.

l1. A stop mechanism having, nation, a driven shaft, speed reducing mechanism therefor, a cam for controlling the effec-tive operation of the speed reducing mechanism, a second cam for rendering thc operation of said first cam eective, and means for varying the timing of said second cam in accordance with the speed of the Shaft.

l2. A stop mechanism having, in combination, a driven shaft, speed reducing mechanism therefor, a cam and a cooperating cam roll for controlling the effective operation of the speed reducing mechanism, a latch for maintaining the cam and cam roll out of engagement, and means for releasing the latch at a predetermined number of degrees of rotation of the driven shaft before the start of the effective operation of the speed reducing mechanism whereby the cam and cam roll are rendered active.

13. A stop mechanism having, in combination, a driven shaft, a speed reducing mechanism therefor, a. latch for maintaining the speed reducing mechanism out of operation, a disk mounted on the shaft, a cam carried by the disk for releasing the latch, a second cam carried by the disk for controlling the effective Operation of the speed reducing mechanism when the latch is released, and means for adjusting the disk circumferentially of the shaft tov vary the timing of the cams in accordance with the speed of the shaft.

14. A stop mechanism having, in combination,.a driven shaft, speed reducing mechanism therefor, a cam for controlling the effective operation of the speed reducing mechanism, a second cam for rendering the operation of said first cam effective, and governor controlled means for simultaneously varying the timing of the two cams in accordance with the speed of the shaft.

15. A stop mechanism having, in combination. a driven shaft, a brake therefor, a disk mounted on the shaft, a cam carried by the disk for controlling the effective operation of the brake, a second cam carried by the disk for rendering the operation of said first cam effective, a member secured to the shaft, centrifugal governor arms pivoted on said member secured to the shaft, and links connecting the governor arms with the disk whereby the disk is adjusted circumferenin combio nation, a

A 1ML/699 tially .of the shaft to vary the timing of the cil-ms in `accordance with the speed of the shaft.

16. A IStor mechanism having, in combi- Eiven member, driving mechanism therefor, means for stopping the rotation of the driven member after the drivin@ mechanism is thrown out, and means, Yfor member is stopped of the driven lnemb of the .driven member before the driven irrespective of the speed er.

ALFRED B. FoWLnR.

Images