US2149513A - Power transmission - Google Patents

Description

March 1939- E. FISCHBACH POWER TRANSMISSION Filed June 6, 1958 INVENTOR. [Au/EL HSCV/BHCH mg zm? ATTORNEY.

Patented Mar. 7, 1939 UNITED "STATES PATENT OFFICE 1 Claim.

This invention relates generally to sewing machines, and more particularly it relates to an arrangement for transmitting power to sewing machines.

In industrial installations it is customary to arrange power driven sewing machines in rows on benches or tables, each table having two rows mounted thereon, both rows being driven from a single power shaft extending between the rows 10 below the table. The operators sit along the edges of the table facing the machines, and the row of operators on one side of the table faces the row of operators on the other side of the table.

This arrangement requires a direction of rota- 15 tion of the machines of one row that is opposite to that of the machines in the other row, and consequently necessitates a different arrangement of belting for driving the machines of one row to that for driving the machines of the other row. Heretofore it has been customary to use a straight belt drive for one row, and a crossed belt drive for the other row. The latter form of drive involves wear on the belts, as the portions of one stretch of the belt rub against the other. This wear is particularly great when the belt joint passes over the contacting portions of the belt going at high speed in the opposite direction. Belt breakage is frequent, resulting in costly ces- 0 sation of production and in repair and replacement costs. If repair is attempted a belt is produced that is joined together in more places than one, and each extra joint increases the rapidity of wear and the frequency of breakages and stop- 5 pages. Among the general objects of my invention is therefore the provision of an arrangement for transmitting power to sewing machines whereby greater efliciency of operation and maintenance may be attained.

It is a further object of my invention to provide a power transmission unit adapted for ready association with a sewing machine. It is also an objectof my invention to provide a power drive for sewing machines that permits a convenient adjustment to suit varying conditions.

These objects and such other objects as will hereinafter appear or be pointed out are attained 1 by the illustrative embodiment of my invention shown in the drawing, wherein:

Figure 1 is a sectional view, taken transversely through an installation comprising a double row shaft;

. of sewing machines driven from a. common power- Figure 2 is an elevational view, on an enlarged scale, of a transmission unit as used for the machines of one of the rows of Figure 1; and

Figure 3 is an end view of the unit of Figure 2 as viewed from the right. 5

Referring now to the drawing for a detailed disclosure of the illustrative embodiment of my invention shown therein, it will be observed that the numeral I0 designates a sewing machine that is representative of one row of machines, while the numeral [2 designates a sewing machine representative of a second row of machines. The machine Ill is mounted on a table section l4 and the machine l2 on a table section l6 and these table sections are. shown as bridged by a trough or channel [8. I

Underneath the trough I8 is shown a power shaft 20, that drives a countershaft 22 positioned below the table section I4, by means of a belt 24 passing over suitable pulleys, and also drives a countershaft 26 positioned underneath the table it, by means of a belt 28 passing over suitable pulleys.

If the power shaft 20 rotates in a clockwise direction (as indicated by the arrow) the countershafts 22 and 26 will also rotate clockwise. The machine I0 is shown as having its driving pulley 30 connected to the drive pulley 32 on the countershaft 22 by a straight belt drive 34, so that the pulley 30 will also rotate clockwise. 39

It is desired to drive the pulley 36 of the machine l2 in a direction opposite to that of the machine Ill. The direction of rotation for the installation shown in the drawing must therefore be counter-clockwise. The arrangement for so doing will now be described.

Mounted onthe bench section I6 is shown a frame 38 carrying two pulleys 40 and 42. These pulleys are mounted in spaced relation, and one of them, 42, may be positioned at a higher level 40 than the other, for a purpose that will presently appear. The pulleys are shown as having their peripheries grooved whereby they are adapted to receive the conventional round belting customarily used on installations of this type.

One of the pulleys, 40, is shown as adjustable mounted on a stub shaft passing through a slot 44 in the frame 38, whereby its distance from the other pulley may be varied. The other pulley, 42, is shown as mounted on a stub shaft 48, fixedly positioned in the frame 38, although it will be understood that if desired, for the purpose of securing extra adjustment, the stub shaft 48 may also be adjustable in the frame 38.

An endless belt 50 is shown as passing from the u drive pulley 52 on the countershaft 26 over the pulley 42, under the pulley 36 of machine l2, over the pulley 46 and back to the pulley 52. This, it will be observed, causes the counterclockwise movement of the pulley 36 of the machine l2, as desired, without any crossing of the belt 50, whereby the wearing away of the belt, due to crossing, is avoided.

It will be observed that the pulleys 40, 36 and 42 are so positioned that the pulley 36 presses the belt 56 inward between the pulleys, whereby a larger arc of contact and better traction are secured. It will further be observed that the tension of the belt may be readily adjusted by strains the position of the stub shaft 44 of pulley 46, by the arrangement already described.

By positioning the pulley '42 higher than the pulley 46 it is possible to readily disengage the pulley 36 of the machine from the belt 50. Where the base plate of the sewing machine is pivotally secured to the table, as for instance by a hinge 54, disengagement may ,be eiiected by: merely lifting the machine about its hinge,,whereby 1its pulley 36 may assume a position 36; Thereby ready access for repairs or inspection is attained. .7 v

The location of the parts might also be made such as to permit the sewing machine tohe slid backward and out. of engagement with the belt 56. This might be effected by slightly lowering the position of pulley 46.

In order to shield the operator I have shown the frame 38 as provided with a guard or shield 54 covering the upper front portion of the pulley 42 in front of the operator.

It will be observed, after the principles of my invention are fully understood, that my invention is not necessarily restricted to sewing machines, but that, as to certain phases thereof, it may have other applications.

, Having thus described my inVention and illustrfated its use, what I claim as new and desire to secure by Letters Patent is:

,; In combination, a pair of opposed tiltable;

frames, a first and a second driven pulley on said frames, respectively, a single driving pulley, means including belts for driving the first driven pulley in "the same direction as that of the driv-' ing pulley; and means for driving the second driven pu lley in a direction opposite to that of the first fdriven pulley, said means including a pair o pa e i ertnlil e slbelt meanscnQQmpass n r id i e p ll s a d said; dr vin pu le to capserot ionu gais .pull s i e ,s ma rection, the said second driven pulley being adapted to 1 frictionally engage the flight of the belt means between, said idler, pulleys, means mounting one of isaid idler, pulleys at a lower level'than said second driven; pulley whereby the latter may, be disengaged from said belt means upon tilting of its supporting frame.

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