US2483037A - Sewing machine - Google Patents

Description

Sept. 27, 3949.

N. V. CHRESTENSEN ETAL.

SEWING MACHINE 3 Sheets-Sheet 1 Filed April 18, 1946 INVENTOR BY fi.

ATTOME p 1949- N. v. CHRISTENSEN ET AL 2,483

SEWING MACHINE Filed April 18, 1948 3 Sheets-Sheet 2 mug lllElll .nwullulllii 7 lllllllllr 56 INVENTORS ATTORNEY Sept. 27, 1949. N. v. CHRlSTENSEN ET AL SEWING MACHINE 3 Sheets-Sheet 3 Filed April 18, 1946 I INVENTOR. BMW

Patented Sept. 27, 1949 UNITED STATES SEWING MACHINE Illinois Application April 18, 1946, Serial No. 663,122

6 Claims. (01. 112218) This invention relates to devices adapted to be associated with sewing machines for delivering a stream of cooling air to the zone or region of movement of the needles so as to prevent overheating of the needles even when the machines are operated at high speed upon relatively coarse and heavy fabrics The devices also are adapted to remove lint and other small particles from the region in which stitching takes place.

An object of the invention has been to provide a simple, compact, and effective arrangement for creatin and delivering a stream of air for needle cooling and lint removing purposes.

Another object has been to provide needle cooling and lint removing means, in association with a sewing machine, which is inexpensive both to construct and to operate.

A further object of the invention has been to so provide and arrange devices of the character indicated as to enable the ready adjustment of the air delivery means to bring about the most effective delivery of the stream of air for the particular purposes of a specific machine or a specific operation.

One feature of the invention is the provision of a connection from the regular operating means for the sewing machine for driving a blower which constitutes the source of the stream of air. This connection is such that the speed at which the blower is driven is dependent upon the speed of operation of the machine. Accordingly, if the speed of the machine is increased, the speed of the blower is also increased and. a reater amount of cooling air will be delivered to the zone of movement of the needle or needles. This is advantageous since the need for the cooling action increases with the speed of operation of the machine.

Preferably the blower, or the source of air supply, is driven at a higher speed than the speed of operation of the machine. Normally the two speeds may be at a ratio of about 2 to 1. However, for some purposes the speed of rotation of the blower rotor may be 3 or 4 times that of the drive shaft of the sewing machine. This enables the benefits of the invention to be derived in connection with operations at relatively slow speed upon exceptionally heavy and coarse materials.

Another feature of the invention is the provision of a simple, readily adjustable support and drive for a blower which carries ample lubricant for a long period of operation.

A special feature or advantage of the invention is that the adjustable mounting of the blower, or other air current source, on the supporting table is such that it provides a simple and efiective means for varying the tension of the belt which connects the sewing machine with the power source.

Other objects, features, and advantages of the invention will appear from the detailed description of certain illustrative embodiments of the same, which will now be given in conjunction with the accompanying drawings, in which:

Figure l is an elevational view of a fragmentary portion of a supportong table carrying a sewing machine, the power means for driving the same, and a blower and associated devices forming part of the present invention,

Figure 2 is an enlarged detail view showing, in longitudinal section, a portion of the conduit embodied in Figure 1;

Figure 3 is an enlarged end view of the arrangement shown in Figure 1, as seen from the left in said figure;

Figure 4 is a detail View in horizontal section along the line 44 of Figure 3;

Figure 5 is a side elevational view, with a portion broken away for clarity of illustration, showing a modified support for the blower; and

Figure 6 is a plan view of the support and blower shown in Figure 5 with a top cover plate removed from the support and with a pulley applied to the driven shaft of the unit.

Turning now to the drawings and referring particularly to Figures 1 to 4. there is shown a supporting table Ill, which, it will be understood, is carried by any suitable leg structure. The table is preferably of a readily portable or shiftable type, enabling movement of the unit into any desired position in a line. On the upper surface of the table Hi there is suitably secured, a sewing machine H which may be of any desired construction. The machine illustrated is of the type disclosed in Patent No. 1.741.095, granted to Norman V. Christensen and Harold J. Le Vesconte, on December 24, 1929. Beneath the table In there is mounted a power unit IQ of any suitable construction, preferably of the type disclosed in the pending application of George Sauer and Clarence C. Smith, Serial No. 638,186. filed on December 29, 1945. commonly known as an electric transmitter, in-- cludes an electric motor 13 and a clutch M havin an axially shiftable, driven shaft 15 which carries a pulley it. For further details as to the construction and operation of the power unit reference may be had to said Sauer and Smith application. The clutch is adapted to be This power unit engaged by the operation of a lever or arm I! through connections from a foot treadle or the like. Rocking of the arm in a counter-clockwise direction, in opposition to a spring i8, serves to shift the shaft l5 and the associated driven clutch member axially toward the left and causes the pulley 16 to be driven at the speed of the motor, which is usually 3450 R. P. M. A belt !9 serves to connect the pulley It with the combined pulley and handwheel 20 of the sewing machine for driving the latter. It will be understood that so long as the clutch is engaged and the sewing machine is driven, the stitch forming instrumentalities of the latter, including one or more needles 25, will be operated and the work introduced between a presser foot 22 and a work supporting arm 23- will be fed in proper relation to the stitch forming means.

The means for producing the desired current of cooling and lint removing air across the zone of operation of the needles comprises a blower 24 which may be of any suitable construction, but is preferably of a relatively small type capable of high speed operation and of generating a current of air in sufficient volume and under suflicient head to produce the desired needle cooling effect. A small blower, such as the type sold under the trade name Airotor, which requires only a small fraction of a horsepower, less than say horsepower for its operation, has been found quite satisfactory for the purpose. The blower is mounted on a Z-shaped bracket 25 which is adjustably secured to the top of the table II! by means of screws 25. These screws cooperate with elongated slots 21 in the lower, horizontally disposed leg 23 of the bracket. The blower has a housing 29 which is secured to the underside of the upper horizontal leg 30 of the bracket by means of a plurality of screws 3 l The blower housing has a laterally extending flange provided around its discharge outlet and this flange receives the screws 3|. The blower has a rotor 32, preferably of squirrel cage construction, mounted on and secured to a shaft 33 which is carried by a bearing lug 34 secured by welding or the like to the vertically disposed leg 35 of the Z-bracket. It will be understood that the shaft 33 extends into the housing 29 and carries the rotor within the latter. At its opposite end the shaft 33 carries a pulley 36 which is secured for rotation with the shaft and which is adapted to bear against a portion of the belt 19 as shown in Figures 1 and 3. If the belt is of V-shape in crosssection, the pulley 36 preferably bears against the fiat outer surface of the belt and for this purpose is provided with a cylindrical outer face, while the sewing machine and transmitter pulleys preferably have V grooves. The housing 29 is provided with relatively large openings in both of its side walls, these openings being in axial alinement with the rotor. The opening on the side toward the vertical portion 35 of the Z-bracket may suitably be somewhat smaller than the diameter of the rotor, while the opening on the opposite side of the housing, as shown in Figure 3, is preferably slightly larger than the outer diameter of the rotor, so that the latter may be inserted through this opening and mounted on or removed from the shaft without removal of the housing. A small ring member 3! may be provided on the outer face of the housing to cover a sufiicient portion of the opening in this face to reduce the diameter of the remaining opening to slightly less than that of the rotor. For the purpose of lubricating the bearings for the shaft 33 there is preferably provided a Gits oil cup 38 which is adapted to supply oil to the central portion of the bearing lug 34. A small annular space may be provided around the shaft at this point by the provision of bearing bushings at each end of the bearing lug 34. This space assists in delivering the oil to the surfaces requiring lubrication.

The laterally extending portion of the upper leg 30 of the Z-bracket is provided with a screw threaded opening which is in line with the outlet for the blower housing 29. This opening is adapted to receive a split coupling fitting 39 which, in turn, receives the lower end of a metal tube 40. As the fitting 39 is screwed into the threaded aperture it will be squeezed more tightly around the tube 40 and will clamp the same in any desired position. This enables both vertical and angular adjustment of the tube. If desired the tube may be of one continuous length extending from the blower to a point adjacent the zone of operation of the needles. However, in order to provide further and more accurate adjustment of the discharge end of the tube, it is preferably formed in two sections. The outer section il is secured to the section 40 by means of a coupling 42, Figure 3, which, as best shown in Figure 2, comprises a sleeve member 43 having threaded portions at both ends adapted to receive nut elements as and Q5. The element 34 serves to clamp an enlarged portion 46 adjacent the end of the tube 50 to the end of the fitting 53. Element 45 serves to clamp packing material 41 against the opposite end of the element 43 and against the outer surface of the tube a l. As shown in Figure 3, the axis of the coupling (32 is preferably horizontal so as to allow swinging of the tube 4| about a horizontal axis at its upper end. If desired thearrangement may be such that this swinging movement may be imparted without loosening of the nut element 55, the friction being such as to cause the tube to remain in any set position. This would be desirable if it were found necessary in the operation of the machine to discontinue the blowing of air across the zone of operation of the needles.

It will be seen that by virtue of the plurality of adjustments made possible by the positioning of the bracket 25' on the table, by the clamping of the tube 40 within the member 39, and by the coupling of the tubes 40 and 4|, the position of the discharge end of the tube 4| may be varied, if desired, to suit the particular requirements of an installation or a particular operation of the machine. Tubes 40 and M are preferably about of an inch in diameter so that an adequate amount of air may be delivered, for needle cooling purposes, at a velocity capable of being developed by a small blower of the type indicated, driven at high speed, i. e., between say 6000 and 12,000 R. P. M. In this connection it should be observed that the size of the pulley 36 is such, in relation to the pulleys I6 and 20, that the blower rotor will be rotated at a much higher angular speed than the main shaft of the sewing machine, The arrangement may be such, for example, that the blower rotor will be driven at double the speed of the machine and thus, if the latter is driven at 4000 R. P. M. the rotor or impeller of the blower will rotate at 8000 R. P. M. Under these conditions a relatively small blower, having a rotor of say 2 inch diameter, is capable of supplying cooling air to the zone of operation of the needles at a velocity and in such quantity as to effect substantial cooling of the needles. The results obtained may be comparable with those set forth in the Rubel application, Serial No. 433,740 new Patent No. 2,423,996, dated July 15, 1947.

As explained in said Rubel application, it is desirable that the cooling air be delivered at a velocity of between and 100 ft./sec.,-prefer ably between 50 and 80 ft./sec., in an amount equal to between .1 and .3 cu. ft. per sec. To accomplish this, the blower is preferably capable of developing a head of between 1.0 and 2.5 inches of water. In general, the principles and conditions set forth in said Rubel application may be considered applicable.

Referring now to Figures 5 and 6, there is shown a modified arrangement of the blower and supporting means therefor. A supporting bracket 48 is provided. This has a main central portion 49 of inverted U-shaped construction and has end angle members 50 and 5| secured to the part 49 in any suitable way, as by welding. Each of the angle members is provided with an outturned foot 52 at its lower end having one or more elongated slots 53 therein for adjustable securement of the support to the top of the table by means of screws. A shaft 54 is mounted within bushings 55 in the opposite legs of the U- shaped member 49. On the outer projecting end of the shaft 54 there is secured a pulley 56 which, as in the first embodiment, is adapted to cooperate with the driving belt IQ of the sewing machine. Within the chamber formed between the legs of the U-shaped member 49 and the end angle members 50 and 5|, there is secured to the shaft 54 a gear 51. The latter meshes with a pinion 58 secured to a shaft 59 mounted in bushings 60 carried by the legs of the member 49.

Shaft 59 projects outwardly from the member if) at the opposite side from that at which the pulley 56 is mounted and it carries the rotor iii of a blower 62 which may be of substantially the same construction as the blower disclosed in connection with Figure 1. The housing 53 of this blower, however, in lieu of having its discharge outlet disposed with its axis vertically, is arranged at an angle, as best shown in Figure 5. Flange 6d at the discharge end of the housing is secured by screws 65 to a plate-like, lateral extension 65 of the angle member 50. This plate-like extension projects laterally from the vertical leg of the angle member 50 and at its upper end is inclined at an appropriate angle, say to the vertical. A split clamping element Bl, having screwthreaded engagement with the plate 66, serves to grip and retain the tube 68. This tube may be of generally the same construction as the tube 40, M of the first embodiment or it may be of a single continuous tube of appropriate shape. A cover plate 69 is provided at the top of the support to retain lubricant within the pocket formed between the legs of the member 59 and the angle members and 5!. It may be retained in any suitable way, as by means of screws. A Gits cup 10 secured to the cover 6!! permits the introduction of lubricant whenever required.

Gear 51 and pinion 58 may be so related as to provide any desired ratio between the speeds of the pulley 56 and the rotor 6 I. In the illustrated embodiment the ratio is 2 to 1. Assuming, for example, that the pulley is rotated at 4000 R. P. M., the rotor 5! will be rotated at 8,000 R. P. M. As in the first embodiment, the pulley 56 may be rotated at a higher speed than the main drive shaft of the sewing machine. This arrangement insures the delivery of an adequate stream of cooling air to effect cooling of the 6. needles even though the sewing machine may itself be operated at a relatively slow speed.

While several illustrative embodiments of the invention have been-disclosed in considerable detail, it will be understood that numerous changes may be made in the construction and arrangement of the various parts without departing from the general principles and scope of the invention.

A The specific dimensions, speeds, and the like given in the foregoing, are to be understood to be simply illustrative of suitable embodiments of the invention.

What we claim is:

1. In combination a supporting member, a sewing machine carried by said member, said machine having stitch-forming devices including a needle, means including a belt for delivering power to said sewing machine for driving the same, a bracket adjustably mounted on said supporting member at a point adjacent said belt, a small low-pressure blower carried by said bracket, means for driving said blower including a shaft supported by said bracket and having a pulley secured thereto in a position for frictional engagement with said belt, said pulley being shiftable towardand away from said belt in the plane of the pulley upon adjustment of said bracket and conduit adjustably mounted on said bracket, and wholly supported thereby said conduit being connected with the outlet of said blower and being arranged to deliver a stream of cooling air therefrom to the zone of operation of said needle.

2. In combination a supporting member, a sewing machine carried by said member, said machine having stitch-forming devices including a needle, means including a belt for delivering power to said sewing machine for driving the same, a bracket adjustably mounted on said supporting member at a point adjacent said belt, a blower carried by said bracket, means for driving said blower including a shaft supported by said bracket and having a pulley secured thereto in position for frictional engagement with said belt, said pulley being shiftable toward and away from said belt in the plane of the pulley upon adjustment of said bracket and a conduit mounted for axial and angular adjustment on said bracket, and wholly supported thereby said conduit being connected with the outlet of said blower and being arranged to deliver a stream of cooling air therefrom to the zone of operation of said needle.

3. In combination a supporting member, a sewing machine carried by said member, said machine having stitch-forming devices including a needle, means including a belt for delivering power to said sewing machine for driving the same, a bracket adjustably mounted on said supporting member at a point adjacent said belt, a small low-pressure blower carried by said bracket, means for driving said blower including a shaft supported by said bracket and having a pulley secured thereto in position for frictional engagement with said belt, said pulley being shiftable toward and away from said belt in the plane of the pulley upon adjustment of said bracket and a conduit adjustably mounted on said bracket for axial adjustment thereon and for bodily movement therewith, said conduit being connected with the outlet of said blower and being arranged to deliver a stream of cooling air therefrom to the zone of operation of said needle, said conduit comprising a plurality of swivelly connected sections arranged to be frictionally held in any selected relation to each other, thereby enabling angular adjustment of the discharge end thereof into a desired active position or into an inactive position.

4. In combination a supporting structure comprising a table top, a sewing machine having a main drive shaft with apower receiving pulley thereon, said machine having stitch-forming devices including a needle, power supplying means including a belt cooperating with said pulley, a support member, means for adjustably securing said support member to said table top adjacent 10 said belt, a shaft carried by said support member and having a pulley secured thereto for cooperation with said belt, the adjustment of said support member being adapted to shift said pulley in the plane of said belt to vary the tension thereof, a small, high speed blower mounted on said member, said blower having a rotor arranged to be driven by said shaft, the connection between said shaft and said rotor being such as to drive said rotor at a higher angular speed than that of 20 said shaft, and a conduit connected with said support member and arranged to deliver a stream of cooling air from said blower to the zone of operation of said needle.

5. In combination a supporting member, a sewing machine carried by said member, said machine having stitch-forming devices including a needle, means including a belt for delivering power to said sewing machine for driving the same, a bracket adjustably mounted on said sup- 30 engagement with said belt, and a conduit connected with the outlet for said blower and arranged to deliver a cooling stream of air to the zone of operation of said needle of said sewing machine.

6. In combination a supporting member, a sewing machine carried by said member, said machine having stitch-forming devices including a needle, means including a belt for delivering power to said sewing machine for driving the same, a bracket adjustably mounted on said supporting member at a point adjacent said belt, said bracket being of generally Z-shaped configuration, means for securing one leg of said Z-shaped bracket to said supporting member, a blower carried by the opposite leg of said Z-shaped bracket, means for driving said blower including a shaft supported by the intermediate connecting portion of said bracket, and having a pulley secured thereto in position for frictional engagement with said belt, said opposite leg of the bracket having a threaded opening in line with the outlet of said blower, and a conduit having one end adjustably connected with said bracket at said threaded opening and its other end positioned adjacent the zone of operation of said needle, said conduit being wholly supported by said bracket.

NORMAN V. CHRISTENSEN. CLARENCE 0. SMITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 286,146 Neely Oct. 2, 1883 1,044,335 Ball Nov. 12, 1912 1,584,944 Johnson May 18, 1926 1,955,384 Herr Apr. 1'7, 1934. 2,316,648 Giglio Apr. 13, 1943

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