US2678013A - Cooling means for sewing machines - Google Patents

Description

May 11, 1954 N. I.. WALLENBERG ET AL 2,678,013

COOLING MEANS FOR SEWING MACHINES ATTORNEY.

May 11, 1954 N. 1 WALLENBERG l-:T Al. 2,678,013

COOLING MEANS FOR SEWING MACHINES Filed March l0, 1951 3 Sheets-Sheet 2 NED L. WALLENBERG JOHN GO ATTWOOD ATTORNEY.

May 11, 1954 N. l.. WALLENBERG ET AL 2,678,013

COOLING MEANS FOR SEWING MACHINES 3 Shee'cS-Sheerl 5 Filed MaICh l0 1951 INVENTORS. NED L. WALLENBERG JOHN G. ATTWOOD ATTORNEY Patented May 11, 1954 COOLING MEANS FOR SEWING MACHINES Ned Leo Wallenberg, Chicago, and John G. Attwood, Oak Park, Ill., assignors to Union Special Machine Company, Chicago, lll., a corporation of Illinois Application March 10, 1951, Serial N0. 214,915

Claims. 1

This invention relates to sewing machines adapted to contain a liquid lubricant for lubricating actuating mechanisms that operate stitch forming devices and associated devices, and more particularly to the provisions in such machines of means for adequately cooling the lubricant.

It is a principal object of this invention to provide a sewing machine having a liquid lubricant contained therein with improved means for effecting adequate indirect cooling of the lubricant.

Another object of the invention is to provide a sewing machine, having a rotary driving shaft, with lubricant cooling means including a fan carried by and rotatable with the shaft, and capable of quiet and substantially Vibrationless operation at sustained high speeds, such as speeds in excess of 5500 R. P. M. of the shaft.

The invention has for a further object the provision of lubricant cooling means for sewing machines, which means are simple and compact in construction and eicient and dependable in operation.

For the purpose of attaining the foregoing objects, a sewing machine constructed in accordance with this invention comprises a hollow frame, preferably made of cast iron, and including spaced front and rear end walls and a partition intermediate the end Walls and dividing the interior of the frame into a front compartment and a rear compartment. The front compartment is closed while the rear compartment has at least one air inlet opening that preferably extends through the rear end wall of the frame and an air outlet opening formed in the bottom of the frame and communicating directly with the atmosphere.

The lower portion of the front compartment constitutes a reservoir for containing a supply of a suitable liquid lubricant, such as an appropriate lubricating oil. A rotary driving shaft extends through both compartments and is supported for rotation in the end walls and par- Sto parts of the actuating means and other elements that are positioned in the lower portion of that compartment. The front compartment also has a removable top cover for ready access to other parts of the actuating means and for introducing lubricant into the reservoir, as required.

Integral with the partition is a plurality of heat radiating elements that are wholly within the rear compartment and that project toward the rear wall of the frame. These elements comprise upstanding spaced-apart heat radiating fins that extend substantially from the bottom to the top of the rear compartment. Also, wholly within the rear compartment is a fan that is secured to and rotatable with the shaft. The ian is adapted, upon rotation of the shaft, to draw a stream of air from the atmosphere into the rear compartment by way of the inlet opening, and the air is directed by the fan toward and along the fins, thereby cooling the fins and partition and, consequently, cooling the lubricant by indirect heat exchange. The air is discharged from the rear compartment through the outlet opening.

The enumerated objects, together with the advantages of the invention, will be readily understood by persons skilled in the. art upon reference to the following detailed description taken in conjunction with the accompanying drawings which respectively describe and illustrate an illustrative sewing machine embodying theinvention.

In the drawings wherein like reference numerals denote corresponding parts throughout the several views:

Figure 1 is a view of the machine, mostly in longitudinal vertical section, taken along the axis of the main driving shaft;

Figure 2` is a horizontal cross-sectional View through the machine shown in Figure l with the cloth plate or work supporting member indicated merely in broken lines; and

Figure 3 is an enlarged end elevational View of the machine as observed from the right of Figure l.

Referring now to the drawings, the machine illustrated therein is an overedge sewing machine that includes a hollow frame IB which is of relatively low, streamlined construction and is provided with a fiat bottom and a curved sloping top, as best shown in Figures 1 and 3. This frame includes a base Il, having a removable bottom plate l2 which is maintained in sealed relation to the remainder of the frame by a Vgasket i3 and screws (not shown), and a removable cover plate |4 that is held in position I6 and a rear end wall I1, the latter wall being provided with a pair of arcuate air inlet through slots or openings I8 (Figure 3).

Intermediate the end walls is a partition I9 that divides the interior of the frame into a closed front compartment and a rear compartment 2i that is open at the bottom, as indicated, to provide an air outlet or discharge opening 22. The partition has a plurality of heat radiating elements or fins 23. These fins, as best shown in Figures 1 and. 2, .extendvertically from the bottom to the top of rear compartment '2| heat radiating surface. f

The lower portion of compartment 2B consti- (Figure 1) and are spaced apart, as shown in Figure 2, to provide a. relatively large4 4 pivotally connected to the lower portion of a presser bar 48. Needle is adapted to cooperate with an under-looper 49 and an overedge looper 5U in the formation of three overedge stitches along the free edge of a piece of work. Mounted on and extending upwardly of the frame is a bracket 5| that supports three thread- tensioning devices 52, 53 and 54 for controlling the tension in the thread delivered, respectively, to needle 45, overedge looper and under-looper 49.

The illustrated machine also has a trimming mechanismY for trimming the edge of the work advance of the; stitching operation. This mechanism includes a movable blade that tutes a reservoir for containing a supply of a suitable liquid lubricant 24 for lubricating major wear-receiving actuating parts of the' machine that are located in the frame above the normal upper level of the` lubricant. Top cover if! is adapted to be easily and quickly removed to permit introduction of the initial supply oi lubricant into compartment 29 or to replenish the lubricant supply, as required.

The frame has a lower extension 25which projects to the left of front wall l5, as viewed in Figure 1. This extension partially encloses and protects certain stitch forming and work feeding devices which must be located exterior compartment Z, and carries a cloth plate 25 having a depending apron 21 that further protects and conceals stitch forming and work feeding devices of the machine. The cloth plate is pivotal with respect to the frame about a pin 28 (Figure 2). A rotary driving shaft 33 for the operating parts of the machine extends longitudinally of the frame, substantially along a line about mid way between the side walls of the frame and midyway between the planes of cloth plate 25 and bottom plate l2. The rear end portion of the shaft is journaled in a ball bearing unit 3l and is mounted in a housing 32 that is positioned in a through opening in rear end wall il and secured to that wall by screws 33. ball bearing unit is enclosed by a cap member 34 Whichts snugly. within housing 32 and is secured thereto either by screws or by a press fit therewith. The rear end portion of shaftt extends outwardly beyond the frame through the bearing unit and carries a combined hand wheel and pulley 35 that is secured to the shaft by a screw 36. Shaft 30 is supported by a sleeve bearing 31 positioned in partition I9. The shaft is supported intermediate partition I9 and wall I6 in a horizontally split bearing 33 that is mounted in a cross member 39 which is integral with the frame casting. The parts of bearing 38 are disposed in a collar 40, bearing 33 and collar 4G being maintained in assembled position in cross bearing 38 by a screw threaded stud 4|. The forward portion of shaft 3i! is supported in sleeve bearings 42 and 43 that are carried by front wall It, bearing 43- being maintained in the illustrated position (Figure 1) by a retainer 44.

The machine is equipped with stitch forming and work feeding devices and actuatingmeans for such devices that may be the saine as or similar to the corresponding devices `and means illustrated and described in pending application of N. L. Wallenberg, J. G. Attwood and J. Sclioij, Serial No. 196,104, led November 17, 1950, and entitled overedge Sewing Machine. Among such devices are a curved needle 45 carried at an end of a needle lever 45 and a presser foot 41 The outer side of the A coacts withV a stationary plate (not shown) in trimming the work; The devices for forming the stitches, for advancing the work and for trimming the work ar'e operated in unison by a suitable actuating means, generally indicated by numeral 5B. The parts of actuating means 56 are preferably the same in construction and operation as corresponding parts disclosed in said N. L. Wallenberg et al. application, Serial No. 196,104, to which reference may be had for further details with respect thereto.

Certain wear-receiving parts of shaft 3i), connections between shafi-S and parts of actuating means 53, connections between relatively movable. parts of the actuating mechanism, and. devices associated with the actuating mechanism are lubricated in a manner that will now be briefly outlined. ln this connection, a splasher 51' is secured by a screw 58 to the periphery of a aange 5d integral with shaft B. Splasher 5l,

i when in its lowermost position, as shown in Figure 1, projects into the body of lubricant 24. During each revolution of shaft 3i) the splasher dips into and out of the lubricant and dings particles of lubricant in the form of a mist or spray into the portion of compartment 20 above the level of the lubricant. Also, a finger 60, carried by a strap 6| that constitutes an element of actuating means 56, dips into and out of the lubricant during each revolution of shaft 30, and generates additional lubricant spray or mist. The lubricant spray lubricates sleeve bearing 3l, excess lubricant, being returned to compartment 20 by way ofA annular groove S2 and an inclined passage 63 that establishes communication between the annular groove and the interior of chamber 20. Shaft 3B is lubricated in the region of split bearing 38 by lubricant spray directed thereto by way of a vertical passage 64 which is formed in cross bar 39, collar 43 and bearing 38. The shaft is similarly lubricated in the region of bearing 42 by lubricant which passes downwardly through a vertical passage 65 formed in the frame and in bearing 42.' The connections between the relatively movable parts of the actuating mechanism are subjected to and thereby lubricated by the lubricant spray or mist within compartment 2?. 1 Parts of the actuating means which extend through front wall l5 are lubricated by the lubricant mist directly or with the aid of suitable wicking (not shown).

For the purpose of supplying lubricant .to sleeve bearing 43 and elements to the left thereof, as viewed in Figure l, we have provided` a passage 66 that extends vertically through frame extension 25, retainer 44 and bearing 43. Wicking E? has its upper part positioned in passage 65 and its lower part immersed in lubricant body 24 and is supported .by a helical. support 68.. .Excess lubricant that ilows to the leftfofbearing 42 or tothe right of bearing 43 is returned tothe body of the lubricant by way of a passage 69. Excess lubrication to the left of front wall i8 drips into the concave upper portion lil of frame extension 5, whence it passes downwardly through a filter unit l! and is returned to the lubricant reservoir. Filter unit il is removably attached to extension 25 by screws i2 for ready removal for cleaning or replacement, as required.

A fan i3, coaxial with shaft Sli, is positioned wholly within rear compartment 2s'. The fan comprises a hub it and a series of blades 'i5 and is adjustably secured to the shaft by a set screw it, During operation of the machine, fan 'it draws a stream of air into compartment 2l through arcuate slots i8. The slots, the fan and heat radiating ns 23 are so arranged that the air drawn into compartment 2l is directed towards and along fins 23 and then discharged from compartment 2i by way of outlet opening 22. This serves to effectively cfel the lubricant within compartment 2% by indirect heat exchange as will be apparent from the foregoing description taken in conjunction with the drawings.

From the foregoing it is believed that the construction, operation and advantages of the herein described embodiment of the invention will be readily vapparent to persons skilled in the art, without further description. It is to be clearly understood, however, that various changes in the apparatus herein shown and described may be resorted to without departing from the spirit of the invention or sacrificing any of the benents.

We claim:

1. In a sewing machine, a closed hollow frame comprising spaced first and second walls and a partition intermediate and spaced from said walls and dividing the interior of said frame into a :first compartment and a second compartment, said partition being connected to and being in heat conductive relation to the Walls of the frame, said second compartment having air inlet and outlet openings communicating with the exterior of said frame, the lower portion of said rst compartment constituting a reservoir for containing a supply of a liquid lubricant, a rotary driving shaft extending through said nrst compartment, stitch forming devices carried by said frame, actuating means for operating said olevices in response to rotation of said shaft, said actuating means being at least partially positioned in said first compartment and adapted to be lubricated by said lubricant upon rotation of said shaft, and a fan in said second compartment and secured to and rotatable with said shaft, said fan being adapted upon rota-tion of said shaft to dra-w a stream of air into said second compartment through said inlet opening, direct said air toward said partition, and discharge said air through said outlet opening.

2. In a sewing machine, a closed hollow frame comprising spaced front and rear end walls and a partition intermediate and spaced from said walls and dividing the interior of said frame into a front compartment and a rear compartment, said partition being connected to and being in heat conductive relation to the walls of said frame, said rear compartment having air inlet and outlet openings communicating with the exterior of said frame, the lower portion of said front compartment constituting a reservoir for containing a supply of a liquid lubricant, a rotary driving shaft extending through. said compartments, said shaft including a rear portion supported for rotation in said rear end wall, means exterior of said frame and attached to said rear portion of said shaft for imparting rotation to said shaft, stitch forming devices car- 'ied by said frame adjacent said front wall, actuating means for operating said devices in response to rotation of said shaft, said actuating means being at least partially positioned in said front compartment and adapted to be lubricated by said lubricant upon rotation of said shaft, and a fan in said rear compartment and secured to and rotatable with said shaft, said fan being adapted upon rotation of said shaft to draw a stream of air into said rear compartment through said inlet opening, direct said air toward said partition, and discharge said air through said outlet opening.

3. In a sewing machine, a closed hollow frame comprising spaced front and rear end walls and a partition intermediate and spaced from said walls and dividing the interior of said frame into a front compartment and a rear compartment, said partition being connected to and being in heat conductive relation to the walls of the frame, said rear compartment having air inlet and outlet openings communicating with the exterior of said frame, the lower portion of said front compartment constituting a reservoir for containing a supply of a liquid lubricant, a rotary driving shaft extending through said compartments, stitch forming devices carried by said frame adjacent said front wall, actuating means for operating said devices in response to rotation of said shaft, said actuating means being at least partially positioned in said front compartment and adapted to be lubricated by said lubricant upon rotation of said shaft, said partition including a plurality of upstanding spaced-apart heat radiating ns that extend substantially from the bottom to the top of said rear compartment, said fins being wholly within said rear compartment and projecting toward said rear end wall, and a fan in said rear compartment and secured to and rotatable with said shaft, said fan being adapted upon rotation of said shaft to draw a stream of air into said rear compartment through said inlet opening, direct said air toward saidheat radiating ns, and discharge said air through said outlet opening.

Ll. A sewing machine in accordance with claim 3, wherein said shaft includes a rear portion supported for rotation in said rear end wall, and means exterior of said frame and attached to said rear portion of said shaft for imparting rotation to said shaft.

5. A sewing machine in accordance with claim 1, wherein said partition includes a plurality of heat radiating elements that project into said second compartment.

References'Cited in the le of this patent UNITED STATES PATENTS fNumber Name Date 2,127,192 Toth, Jr Aug. 16, 1938 2,144,326 Callaghan Jan. 17, 1939 2,249,615 Lutz July 15, 1941 2,432,285 Christensen et al. Dec. 9, 194'?

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