US2829740A - Brake means - Google Patents

Description

V. T. STACK BRAKE MEANS April s, 1958 2 Sheets-Sheet 1 Filed Sept. 8, 1955 fllllllfi@lw:l

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V. T. STACK April 8, 1958 BRAKE MEANS 2 Sheets-Sheet 2 Filed Sept. 8, 1955 BY 6% a My ATTORNEYS.

United States Patent BRAKE MEANS Vernon Thomas Stack, Winston-Salem, N. C., assignor to' Hanes Hosiery Mills Company, Winston-Salem, N. C., a corporation of North Carolina Application September 8, 1955, Serial No. 533,127

2 Claims. (Cl. 188-83) This invention relates to brake means. More specifically, it is concerned with brake means for restraining intermittently rotated machine elements, such, for example as the pattern drum shafts of a circular hosiery knitting machine, against overthrow to prevent untiming of successive knitting phases and/ or derangement and/ or damage to various mechanisms controlled from said shafts. The means ordinarily provided for this purpose consists merely of a leaf spring with a friction pad to bear upon one of the faces of a drum, there being no way to adjust the pressure of the brake shoe or to compensate for wear except by removing the spring and bending it to increase or decrease the shoe pressure and to thereafter replace the spring. Considerable time is consumed for this accomplishment with the machine idled and with loss in the production therefrom.

The chief aim of my invention is to overcome the aforementioned drawbacks. This objective is realized in practice, as hereinafter more fully set forth, through.

provision of a simple brake means which can be relied upon to effectively restrain the intermittently rotated element against overthrow as it is stepped about, and which can be accurately adjusted from time to time, as may be required for Wear take up without the necessity for removal from the machine.

Other objects and attendant advantages will appear from the following detailed description of the attached drawings, wherein:

Fig. l is a fragmentary view, in side elevation, showing a portion of the pattern mechanism of a circular hosiery knitting machine with brake means conveniently embodying my invention.

Fig. 2 is a horizontal section taken as indicated by the angled arrows II-II in Fig. 1; and

Fig. 3 is a fragmentary view in front elevation looking as indicated by the angled arrows IIIIII in Fig. 1.

The pattern mechanism herein exemplified is generally of the construction disclosed in U. S. Patent 1,152,850 granted to R. W. Scott on September 7, 1915. The belt shipper cam disk or drum designated 1 is fixedly secured to a horizontal shaft 2 to one side of a bearing 3 provided for the latter on a vertical portion 4 of the machine frame 5. The drum 1 has the usual peripheral notches 6 for engagement by a hook pawl 7 pivotally suspended from an arm 8 free on the shaft 9, about which shaft the usual segmental gear 10 (Fig. 2) oscillates. The arm 8 is arranged to be actuated through engagement of a finger projection 11 thereon by a peripheral cam rise 12 on the usual high speed gear 13 of the machine. Affixed to the shaft 2 to the left of the bearing 3 (Fig. 3) is a toothed wheel 15 adapted to be picked by a pawl 16 pivotally connected to a crank lug 17 on the hub 18 of the segmental gear 10. The purpose and functioning of this pattern mechanism is Well known and is fully set forth in the Scott patent, supra, and need not therefore be described in detail herein.

The improved brake means which I have devised for Patented Apr. s, 1955 restraining and thereby preventing overthrow of the drum shaft 2 when intermittently rotated by the action of either of the two pawls 7 or 16, includes an element'20 in the form of a bell crank lever having arm projections 21 and 22 respectively adjacent the upper and lower ends of an upright arbor 23. As shown, the arbor 23 is formed with diametrically-reduced shouldered upper and lower ends 25 and 26 which are rotatively engaged respectively in a bearing lug 27 fixedly secured to the vertical portion 4 of the machine frame 5, and in a socket boss 28 on the base portion of said frame. The collar indicated at 30 serves to hold the element 20 in place. It will be noted that the arm 21 of the element 20-is at the level of the drum shaft 2'and is provided with vertically spaced apertures, through which are slidingly engaged, rearward pin projections 31 of a backing plate 32 whereto is secured, by screws 33, a replaceable brake pad or shoe 35 of suitable non-metallic friction material. Surrounding the pins 31 in the interval between the arm 21 of the element 2t and the backing plate 32, are helical compression springs 36; and threadedly engaged in the distal end of the lower arm 22 of said element, is an adjusting screw 37 which bears against a stop lug 38 fixedly secured to the machine frame 5.

By rotating the adjusting screw 37 in one direction, the element 20 is turned counterclockwise in Fig. 2 with consequent further compression of the springs 36 and increase in the braking power of the friction shoe 35. On the other hand, by rotating the adjusting screw 37 in the opposite direction, the element 20 is moved clockwise in Fig. 2, with attendant relaxation of the springs 36 and easement of the pressure of the brake shoe 35 upon the drum 1. It will thus be seen that the pressure of the brake can be accurately adjusted to impose just sufficient restraint upon the drum 1 initially, or as may be required subsequently, from time to time, for wear take up, to insure against excess rotation of the shaft 2 at each actuation of either of the pawls 7 or 16. Obviously such adjustments can be made quickly and easily without removal of any part of the device from the machine, the adjusting screw 37 being readily accessible for screw driver operation from the front of the machine. Since it is simple in construction, the brake means of my invention can be very economically produced in quantity at small cost; and since it is in the form of an attachment, it can be applied to existent machines at small cost considered from the standpoint of labor expense.

While, for the purposes of exemplification, I have shown and described my invention in connection with a hosiery knitting machine, its use is not to be considered as so 7 restricted since it can be used, without sacrifice of any of its inherent advantages, in connection with other kinds of machines. The broader of the appended claims are therefore to be construed with this in mind.

Having thus described my invention, I claim:

1. Brake mechanism for use in connection with a circular knitting machine having a frame with a horizontal portion, and a narrow upright portion rising from the horizontal portion, an intermittently-rotated horizontal shaft journalled in said upright frame portion, and disks respectively mounted on the shaft immediately adjacent opposite sides of said upright frame portion with their peripheries extending beyond said upright portion; said brake means comprising a member pivoted to rock about a vertical axis in the plane of the upright frame portion in the interval between the two disks, said member having an arm at the elevation of the shaft, and another arm at a lower level; a friction shoe supported, with interposition of compression spring means, at the distal end of the upper arm of the member for engaging the contiguous side face of one of the disks; and a regulating screw threadedly engaged in a projection on the horizontal frame portion of the machine, with the distal end of. its References Cited in the file of this patent shankhearing-against the lower arm of said member, for UNITED STATES PATENTS ad usting the pressure effect of the spring means upon the brake shoe-r V 811,010 W r Jan. 30, 1906 2-. The invention according to claim 1 wherein the 5 1,152,850 Scott P 1 1915 friction shoe is secured to a backing plate having a pair 1,567,915 Cole 291 1925 of spaced rearward pin projections loosely engaged in a i z g -1g t"th fth b;dhei aee fly,

p was m 6 pp arm 0 e mem er all W 11 7 Sle ght Dfic. 12 1950 the spring means comprises helical coils of Wire which surround the pin projections between the shoe-backing 10 plate and the upper arm of the member.

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