US2676683A - Starting and stopping mechanism - Google Patents

Description

H. SCHWABE April 27, 1954 STARTING AND STOPPING MECHANISM Filed March 29, 1951 III IN V ENTOR BY/M Qdumk ATTORNEY April 27, 1954 H. SCHWABE 2,676,683

STARTING AND STOPPING MECHANISM Filed March 29, 1951 2 Sheets-Sheet 2 Fig. 2 25 ENTOR ATTORNEYS Patented Apr. 27, 1954 UNITED" STAT 's. PATENT OFFICE 2,676,683. 7 sranrmc ANIisToPPING MECHANISM" Herman Schwabe, Nevi York; N. Y., assignm to Herman Schwabe, Incl, New York; N. Y. Application March 29, 1951; sci-nine. 218,149

V 1 This invention comprises'a'new andirnproved starting and stopping mechanism for clicking presses of the type disclosed in United States Letters Patent No. 921,503, Mayll, 19095 Clicking machines of the'type set forth in'the' aforementioned LettersPatent comprise a cutytingblock for supporting leather or other sheet material, and a presser member mounted upon apost and arranged for movement into" and out of operativerelation to a freely movable'die positioned by the operator upon the material. In producing cutting operations upon the material,

' the post is reciprocated by means of an eccentric mounted on a shaft driven by'a pulley or a flywheel, connection being made between the shaft and fly-wheel by a one-revolution clutch operable at the will of the operator. Such machines have been equipped with 'a brake comprising a strap running. around a drum on the shaft so 'thatat the end of one revolution. of the shaft the brake is rendered enective to bringthe parts to rest with the presser member-substantially in its highest position above. the work.

In view of the foregoing, an'objec't offthe present invention is to provide startingand stopping mechanism for an improved clicking. machine which, without sacrificing any'of the characteristic advantages of such mechanisms heretofore in use, will be eifective to reduce the amount of power required for operation while making it practicable to reduce the size of various parts of the machine.

The machine of said patent-comes to rest after eachoperation withrtheb rake" fully appliedand -must be started under the same condition, that "istosay, the brake is not released until-the main shaft of the machine has rotated suniciently to cause an eccentric to release the brake. Such procedure is extremely wasteful of power, tends to make the machine sluggish in action, and imposes unnecessary strain on all parts of the mechanism. Various attempts have'been made to remedy this serious defect but heretofore they have all involved complicated and trappy systems, expensive to produce and troublesome to maintain in proper adjustment. The present invention comprises a simple and effective solution of this problem which has plagued manufacturers 'of clicking presses for many years.

Going into more detail, the mechanism of my invention is characterized-by a rocker lever for setting the brake band and this lever has a shiftable fulcrum-the position of which is manually controlled'by the means for tripping the clutch. These parts are so designed that simultaneously 'may be had to said Patent No. 921,503.

In thedrawings is shown a portion of the main operates the brake applying and 2, Withthe' engagement of the clutch, the fulcrum of the rocker lever'is shifted in a direction to release the brake band with the result that the 'm'ain' shaft of the machine is free to turn from partly in section on the V the clicking press is shown as is necessary for understanding of the presentinvention, and for further details of the machine itself reference frame ['0 inwhich is journaled the shaft H on which is" formed the main driving eccentric 12 of the machine. This is encircledby a strap or follower i3 having upwardly extending forks 54 to which is connected the lower end of the post (not shown) of the machine.

From the lower side of the eccentric extends afork' it which releasing mechanismas will presently appear.

, The. main shaft .i i carries at its right hand end, as shown in Fig. 1, a combined driving pulley and fiy-wheel IShaving a chamber in which islocated an. expanding, ring clutch iii having a I an operating arm I8 which is oscillated by a longitudinally movable bolt 13 to expand and contract the clutchring if in engaging anddisengaging the clutch with respect to the pulley it which, it will be understood, is the loose ember of the clutch. A drum 29, which is the fast member of the clutch, carries the bolt 1 9 and the clutch ring IT. The bolt is is operated by a Wedge cam 2|, best shown in Fig. 2, which is carried by an arm 22 fast to a shaft 23 journaled in the machine frame in bearings located above the main shaft II. A second arm 24 is fast to the shaft 23 and to the outer end of this is connected a vertical link 25 that in turn is connected to the starting handle of the machine and lifted by the operator when he wishes to have the machine make a cutting stroke.

The drum 20 is provided with a circumferential braking portion about which passes a band brake 26. This has at its lower end a swivel connection through a link 21 with a rocker lever 28 which is connected at its other end through a link 29 V to a fork l of the eccentric strap above referred to. The rocker lever 28 has a fulcrum shaft 30 journaled in bearing blocks 3| which are slidable vertically in ways provided for them in a forked bracket 32 fast to the machine frame. The shaft 30 passes through the forked arms 33 of a toggle link which is connected through a toggle pin 34 to a second toggle link 35 depending from an anchor pin 36 fixed in the machine frame. When this toggle is straightened, the fulcrum shaft 30 of the rocker lever 28 is held rigidly in its lowermost position as shown in Fig. 1, and it will be understood that the brake band is applied while the fulcrum shaft is held in this position and maintained therein while the machine is at rest. The toggle link 33 is provided withan upwardly extending stop lug 31 which bears againstthe hub of the upper toggle link 35 when the toggle system is straightened and so determines its normal operative position.

A tension spring 38 extends between alug projecting from one sidefof the toggle link 35 anda clip secured to the frame of the machine and tends always to move the toggle links into straightened position. To the outer, end of the angular toggle link 33 is pivotally connected a vertical rod 39 having at its upper end pivotal connection with the outer end .of an arm 40 fast to the shaft 23 already mentioned.

It will be understood that the bolt 19 is chambered to receive a compression spring tending always to move the bolt toward the right as seen in Fig. 1 and cause the clutch to engage. When the wedge cam 2| is lowered it positively moves the bolt toward the left. and holds it in its clutch disengaging position as shown in the same figure.

From the foregoing description it will be apparent that when the vertical rod or link 25 is lifted by depression of the starting handle, two actions will simultaneously occur: (1) thewedge cam 21 will be lifted permitting the clutch to engage, and (2) the toggle links 33, 35 willbe broken thereby shifting the fulcrum shaft 30 and the right end of the rocker 28 upwardly and releasing the brake band 26 from its engagement with the brake drum 20. Accordingly, when the clutch engages, starting the rotation of the main shaft I l, the brake will be released and the shaft entirely free to turn.

Having thus disclosed my invention and described in detail an illustrative embodiment thereof, I claim as new and desire to secure by Letters Patent:

1. Starting and stopping mechanism for a clicking press or the like comprising a frame, a rotary shaft journaled therein, a brake drum on the shaft, a brake band cooperating with the 2. In starting and drum, an eccentric on the shaft, means for tightening the brake band about the drum including a brake lever having a movable fulcrum together with connections to said brake band and connections to the eccentric for rocking said lever to cause braking application of the brake band to the drum, and operator-controlled means for initiating the rotation of the shaft and for simultaneously shifting the fulcrumof the said brake lever to release the brake band prior to rotation of the shaft.

stopping mechanism for a like having an eccentrica clutch and a brake band clicking press or the operated striking arm,

set when the clutch is released to stop the press,

a rocker. lever -connected to the brake band and having a shiftable fulcrum, power mechanism for moving the rocker lever to set the brake, and manually controlled means for tripping the clutch and simultaneously causing shifting of said fulcrum whereby the said rocker lever is moved to release the brake.

3. In starting and stopping mechanism for a clicking press or the like having an eccentricoperated brake band, a rocker lever connected to the band and having a fulcrum shaft, slidably mounted journal boxes for said shaft, power mechanism for moving the rocker lever to apply the brake, toggle links maintaining said journal boxes in fixed operative position, and manually operated mechanism for temporarily breaking the toggle links to shift the fulcrum shaft and permit movement of the rocker lever into band releasing position.

1. In starting and stopping mechanism for a clicking press or the like having a shaft with a single eccentric for reciprocating the post of the machine and applying a brake band to stop rotation of the shaft; a rocker lever connected to the brake band and having a shiftable fulcrum shaft, connections between the eccentric and rocker lever for applying the brake, toggle links movably supporting said fulcrum shaft, means for positively determining the straightened and operative position of the toggle links, and a manually operated link connected to one of the toggle links and being movable to break the links and thus shift the fulcrum of the rocker lever and the lever itself to a band releasing position.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,953,067 Ballard Apr. 3, 1934 2,090,661 Bates et al. Aug. 24, 1937 2,496,040 Criley Jan. 31, 1950

Images