US1596487A - Ventilated rotary-hook mechanism - Google Patents

Description

R. K. HOHMANN ET AL VENTILATED ROTARY HOOK MECHANISM Fil ed Sept. 22; 1924.

u A I 10 IINVENTORS K 0&1 Z

- ATTORNEY Patented Aug. 17, 1926.

. STATES PATENT. OFFICE.

RICHARD K. HOHMANN, OF PERU, INDIANA, AND DAVID BESWICK, 0F BROOKLYN, NEW YORK; SAID I-IOHMANN ASSIGNOR OF HIS ENTIRE RIGHT TO HOHMANN SEWING- MACHINE COIMPANY, 0F PERU, INDIANA, A CORPORATION OF INDIANA, AND SAID IBESWIGK ASSIGNOR OF HIS ENTIRE RIGHT TO FREDERICK OSANN COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VENTILATED ROTARY-HOOK MECHANISM.

Application filed September 22, 1924. Serial No. 739,022.

The object of the present invention is to mechative provisions whereby it acts as a fan to draw air over its surfaces and those of the carrier to thereby absorb and dissipate the frictional heat developed in operation. Advantageously also, the carrier or bobbin housing is formed with a special ventilating passage. The invention is of particular utility in connection with the high speed big bobbin machines heretofore developed by one of us, to-wit: Richard K. Hohmann, on account of the very high peripheral speed of the surfaces of the hook running in contact with the carrier surfaces.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification; but for a better understandin of the invention, its advantages and speci c objects attained with, it, reference should, be had to the accompanying drawing and descriptive matter inwhich we have illustrated and described a preferred embodiment of the invention.

Of the drawings:

Fig. 1' is afront elevation of the rotary stitch forming mechanism of a rotary hook sewing machine;

Fig. 2 is a section on the line 22 of.

Fig. 1;

Fig. 3 is a section on the line 3-3 of Fig. 2; Fig. 4 is a perspective view of a portion of the rotary hook member; and

Fig. *5 is'an elevation of another POT. tion of the rotary hook member. I

The rotary hook member A illustrated in the drawings-comprises a hub portion adapted to be secured on the end of the hook shaft (.not shown), and spoke arms A 'integrally connecting the hub toa cylindrical rim portion A A second hook rim part A has a portion fitting overthe rim part A and is secured to the latter as by means of screws B tapped into the rim part A and passing through holes A in the rim part A. The rim part A is provided with an internal rojecting rib or flange A at its'front end forming the front wall of a circumferential bearing groove C, the rear wall of which is formed by the front edge of the rim portion A and the outer wall of which is formed by the body of the rim part A. The rim portion of the hook member is notched to form a loop engaging beak A", and the beak forming notch is spanned by the usual deflector strip D.

- The bearing groove C in the hook member receives the bearing rim E of the nonrotating thread carrier or bobbin housing E. The latter is shown as having the usual provisions E forholding the thread carrier against rotation with the hook member, and is notched to provide the usual thread engaging hook E and opposing shoulder E The bobbin housing is provided with a central post E on which is normally secured the sleeve portion F of a separable bobbin housing part F which is latched in place on the end of the post E by a latch member G. H represents a thread bobbin journalled on the sleeve F.

The rotary hook member and bobbin housing, in so' far as they have been described above, embody no feature of the present invention, but on the contrary are of the type previo usly developed by Richard K. Hohmann for use in 'a high speed big ,bobbin machine with which the present invention may be'employed with-especial advantage because of the high peripheral speed of the hook member. In such a machine the diameter of the thread housing bearing rim may well be an inch and a half orso, and the hook member may make eight or nine thousand revolutions er minute. With such relative speed of t e contacting surfaces of lubricated. The heating up of the contacting surfaces is objectionable as it increases the frictional wear, and is further objectionable because it makes the bobbin housing part F too hot for comfortable handling by the operator in effecting bobbin replacements. I

To avoid this heating up of the parts, we have provided the mechanism shown with simple and effective ventilating provisions which co-operate to create an-air fiow over the surfaces of, the hook member and housing effectually cooling these parts." These provisions, in the preferred construction illustrated, comprise fan blades I secured to the spider arms AT of the hook member A. These blades may be strai ht or curved, as shown, to correspond to t e contour of the front edges of the arms A and extcnd outward a short distance beyond the periphery of the rim portion A and extend rearward some distance beyond the arms A. A disc K at the rear of the blades fits snugly about the hub portion of the hook member, and is secured against the rear edges of the fan blades I by rivets M by which the disc K is secured to the arms A. L represents spacing Washers surrounding the rivets M. With this arrangement the disc K forms the rear wall of the fan chamber of a centrifugal fan. The blades I draw air into this fan chamber from the space surrounded by the rim of the hook member A, and this air is discharged at the periphery of the fan chamber.

In addition to the ventilating provisions formed by the fan blades I and associated parts, we advantageously form ports or channels A through the portion of the rim of the hook member A forming the outer wall of the bearing groove C. The walls of the ports A 9 serve as fan vanes to create a flow of air through the bearing groove. The fan action thus provided for might be a centrlfugal' fan action, but advantageously as shown, the ports are forwardly inclined to obtain an lmpulse fan action whereby air is drawn into the outer ends of the ports A and is delivered at the inner ends of the ports into the bearing groove 0. To augment the impulse fan action, the outer ends of the ports A are enlarged as by counters1nk1ng, the enlargements A 'being mainly at the forward sides of the axes of the ports A. To furtherthe fan action of the channels or ports A, we advantageously form a peripheral groove E in the bearing rim E of the bobbin housing .member E. The groove E may well be open at its end adjacent the shoulder E, but will ordinarily be closed at its other end. The groove 6 is open to the interior of the hook chamber through the usual thread clearing slots E formed in the bearing rim.

With the simple and effective provisions described air is drawn into the hook member through the ports A into immediate contact with the engaging surfaces of the hook member and bobbin housing. The air circulation thus obtained, is augmented by the action of the fan blades I which continu-.

ation, while without such provisions a, few

minutes operation of the mechanism will heat the bobbin housing so hot asto make it practically impossible for the operator to handle it with bare hands.

While in accordance with the provisions of the statuteswe have illustrated and ,described the best form of our invention now known to us, it will be apparent to those skilled in the art that changes in the form of apparatus specifically illustrated and. de-

scribed herein may be made without departing from the spirit of our invention as set forth in the appended claims, and that certain features of our invention may sometimes be employedwith advantage without a correslponding use of other features. I

aving now described our invention what we claim as new and desire to secure by Letters Patent is: 1. In a rotary hook sewing machine mech anism comprisin a rotating hook member having a bobbin ousing chamber and a 'nonrotating bobbin housing mounted in said chamber, the improvement which consists in provisions creatmg a fan action drawing air through said chamber and comprising a fan chamber at the rear of the first mentioned chamber receiving air from the latter and discharging it at the periphery of the fan chamber.

2. In a rotary hook sewing machine mechanism comprising a rotating hook member having an internal bearing groove and a non-rotating bobbin housing journalled in said groove, the improvement which consists in provisions for creating a fan action forcing air through said groove comprising ports through the peripheral wall of the bearing groove. 1

3. In a rotaryhook sewing machine mechanism comprising a rotating hook\ member having an internal bearing groove and a non-rotating'bobbin housing journalled in said groove, the improvement which consists in provisions for creating a fan action forcing air through said groove comprising forwardly inclined ports through the peripheral wall of the bearing groove.

4. In a rotary hook sewing machine mechanism comprising a rotating hook member having an internal bearing groove with ports in the peripheral wall of the groove, and a non-rotating bobbin housing having a bearing rib mounted in said groove and formed with a periphreal channel.

5. In a rotary hook sewing machine mechanism comprising a rotating hook member having an internal bearing groove and a non-rotating bobbin housing mounted therein, the improvement which consists in for wardly inclined ports extending through the peripheral wall of said bearing groove, and

provisions incorporated in the hook member for creating a fan action drawing air out of w the hook at the rear of the latter.

6. A rotary hook member for a rotary hook sewing machine comprising hub and rim portions and arms connecting said portions, fan blade ports extending 'rearwardly 20 Kings and State of New York, this 19th day 25 of September, A. D. 1924.

RICHARD K. HOHMANN. DAVID BESWICK.

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