Sewing machine needle cooler
FIELD OF THE INVENTION 
     The present invention relates to sewing machines and more particularly to an apparatus for cooling the sewing machine needle means. 
     BACKGROUND OF THE INVENTION 
     Incident to the high speed operation of machines of the kind referred to, considerable heat is generated by the reciprocation of sewing machine needles through a workpiece. The excessive heat of the needle, especially when sewing synthetic fabrics, may cause either melting of the fabric workpiece or the breaking of the thread passing through the needle eye. This condition is aggravated by the limited space requirements provided for placing a needle cooler relative to the needle but yet allowing operator access to the sewing area. 
     The purpose of this invention is to obviate these problems and to obtain greater efficiency and economy in operation of such machine. This purpose is accomplished by the provision of a pneumatically actuated mechanism operable, incident to machine operation, to biasably maneuver a needle cooling apparatus between an operative position, whereat a nozzle may be arranged closely adjacent the sewing machine needles to disperse a cooling medium thereagainst, and an inoperative position. In its inoperative position, the needle cooler is removed from the zone of the needles whereby providing operator access to the sewing area. The needle cooler is biased into its operative position under a constant but yielding pressure such that, if necessary, the nozzle may be temporarily displaced from the sewing area or zone but is then automatically returned to its operative position. A positive stop incorporated into the design of the needle cooler assures constant and proper positioning of the nozzles relative to the sewing machine needles. Because the present invention is activated incident to machine operation, the machine operator need not be concerned whether the needle cooler has been activated. In addition, means may be provided to automatically retract the needle cooler from its operative position upon completion of the sewing operation whereby allowing operator access to the machine. 
     In one form of the device, the needle cooler may include a distendable arm which carries the cooling nozzles toward the sewing zone of the machine. In its distended position, the arm may be arranged such that it extends proximate to and crosswise of the reciprocal path of the needles. 
     In line with all of the above, it is a primary object of this invention to provide a sewing machine needle cooler which, incident to machine operation, is maneuverable between a first disposition whereat a cooling medium is discharged against the sewing machine needles, and a second disposition, the latter position allowing operator access to the sewing area. 
     Another object of this invention is the provision of a needle cooler which is readily adapted to a wide range of machines, is inexpensive and economical in its operation. 
     A further object of this invention is to provide means operative to maintain the sewing machine needle cool while operating but which provides operator access to the sewing area when the machine is inoperative. 
     Another object of the invention is to provide a sewing machine needle cooling device which may be detachably secured to the sewing machine without significant alteration or modification of the machine itself. 
     It is a further object of this invention to provide a needle cooler which is biased into an operative position by a pneumatic system which allows the needle cooler to be temporarily displaced from its operative position and automatically returned thereto during the sewing operation. 
    
    
     Other objects and a fuller understanding of the invention may be had by referring to the following disclosure and claims, taken in conjunction with the accompanying drawings in which: 
     FIG. 1 is a fragmentary front elevational view of a portion of a sewing machine embodying the invention; 
     FIG. 2 is a fragmentary side elevational view of the machine illustrated in FIG. 1; 
     FIG. 3 is a sectional view of a presently preferred form of a needle cooling device; 
     FIG. 4 is a schematic illustration of a pneumatic system comprising a portion of the present invention; 
     FIG. 5 is a end view of the needle cooler taken along line 5--5 of FIG. 3. 
    
    
     DETAILED DESCRIPTION OF A PRESENTLY PREFERRED EMBODIMENT 
     Referring now to the drawings, wherein like reference numerals indicate like parts throughout the several views, there is shown a portion of a sewing machine 10. The machine 10 may be of any suitable character intended or adapted for operation at such speeds or under such conditions as to make cooling of the sewing needles either necessary or desirable. Suffice it to say, the machine illustrated includes a frame comprising a base 12 with a work supporting surface 14 and an arm 16 terminating in a head 18 overhanging the base 12. The machine is provided with the usual sewing devices including a presser bar, a presser foot, needle bar means and etc. The needle bar 20 is mounted in the head for vertical, endwise reciprocation and at its lower end carries one or more needle means 22 defining a sewing area or zone. The needle means are adapted to cooperate, in a well known manner, with complimentary lower stitch forming means (not shown) arranged beneath the work supporting surface, thus producing a seam or a plurality of lines of stitching of appropriate character. Since the sewing machine proper is of conventional form, it need not be described in further detail. 
     As schematically represented in FIG. 4, power for driving the machine 10 is supplied by means of a driving motor or transmitter 24. The transmitter unit is operatively connected to the machine and may be operated, at will, by an operator controlled treadle 26. This construction is such that the machine may be intermittently operated simply by rocking the foot treadle 26 whereby actuating the motor and thereby the machine. 
     The novel needle cooler of the present invention, generally designated as 30, is shown in FIGS. 1 and 2 as attached to a depending arm 32 of a bracket 34 which, in turn, is detachably secured to the head 18 of the machine. By such construction, the needle cooler is independently mounted of any sewing machine movable part whereby eliminating any inertia effect. As shown additionally in FIG. 3, the needle cooler 30 is a fluidically actuated, maneuverable device that is operative incident to the actuation of the machine and is adapted for movement between two dispositions. In one presently preferred form, the needle cooler 30 includes an open ended housing 36 that may be detachably secured to the bracket arm 32. The housing 36 may be cylindrical in shape and has an internal cylindrical piston chamber 38. Telescopically disposed within the piston chamber in a maneuverable manner permitting bodily shifting thereof, is a pneumatically responsive component or piston member 40. The piston member includes a piston head 42 including a sealing means 44 and a stem or conduit portion 46 which, when axially extended, protrudes beyond the housing 36. At its distal end, the piston member 40 is provided with nozzle or exhaust port means 48. The exhaust port means communicate with a longitudinal bore 50 provided in and extending substanially the length of the piston member 40. The exhaust port means 48 correspond in number to the needle means 22. 
     Turning to FIG. 4, for distending the piston member or conduit means into its operative position (shown in FIG. 3) thereby situating the nozzle means to cool the needles, the needle cooler is connected to a valve unit 52. The unit 52 is connected to a pressurized source of cooling medium 54 and includes a valve that will expose a pressurized cooling medium to the rearward side of the piston when the valve is actuated whereby effecting its movement. In the preferred form, the pressure cooling medium is air but other fluidic means could be used without distracting from the spirit and scope of the present invention. As will be appreciated, when in its operative position, the stem portion 46 of the piston member or conduit 40 is positionally distended into the zone of the sewing area such that the cooling medium discharged from the nozzle means is directed against the needle whereby cooling same. 
     As shown in FIG. 5, for guiding the piston member whereby assuring a proper relationship between the nozzle means and the needles, a guide means 56 is provided. In its preferred form, the guide means includes a guide finger 58 which is secured to the housing 36 and which cooperates with a channel 60 provided along the periphery of the piston&#39;s stem portion 46 to prevent the piston from turning. 
     The maneuverable needle cooler of this invention is further provided with a positive stop to assure proper positioning of the nozzle means with respect to the sewing machine needles. Because the preferred form of the present invention includes an axially distendable piston, the means for assuring proper positioning of the nozzles relative to the needles includes a step 62 provided in the cylindrical chamber 38 of the housing 36 and which cooperates with the piston head 42. By this construction, the position of the step 62 limits the telescopic movement of the piston member 40 toward the zone of the needles. Accordingly, the nozzle or exhaust port means 48 are accurately positioned relative to the needles under the influence of the pressurized cooling medium. 
     Turning again to FIGS. 1 and 2, the movement of the piston member 40 has a horizontal component. In its fully distended position the stem portion 46 of the piston member 40 extends proximate to and crosswise of the reciprocal path of the sewing machine needle means. Also, because the piston member is yieldably biased into its operative position, it may be temporarily retracted and then, because of the constant pressure being applied by the pressurized cooling medium, automatically returned to its operative position. Upon completion of the sewing operation, the pressure to the piston member is relieved and the piston may be retracted to its nonoperative position whereby yielding access to the sewing area. 
     Means for automatically retracting the needle cooler upon cessation of the sewing operation may also be provided. To accomplish this purpose, and as may be best seen in FIG. 3, a compression spring 64 acting in opposition to the force created by the pressurized cooling medium and disposed between the piston head 42 and the housing 36 may be provided. In this manner, when the pressure in the housing chamber 38 decreases, at the completion of the sewing operation, the spring 64 may forcibly return the piston member 40 to its nonoperative position whereby removing the nozzle means 48 from the area proximate the needles. 
     Prior to operation of the machine, the needle cooling means may be arranged in a nonoperative position to allow operator access to the sewing area. Incident to the operation of the machine, the valve unit 52 is actuated by the operator&#39;s action on the treadle 26. As a result, the fluid pressure controlled mechanism of the present invention is activated to maneuver the nozzle means from an inoperative position to an operative position whereat they are in position to cool the needles. It is also conceivable to pneumatically operate the needle cooling means independent of the machine operation without stealing from the intended spirit and scope of this invention. Actuation of the valve 52 allows the pressurized cooling medium to pass into the piston chamber rearwardly of the piston head 42 whereby forcibly distending the stem portion 46 of the piston 40 into its operative position whereat it is positively stopped. By means of the longitudinal conduit 50, the pressurized cooling medium is delivered to the nozzle means 48 and ultimately dispersed against the needles 22 in a direction generally transverse or diverse to the direction of movement of the stem portion. The conduit or piston 40 remains distended under this biasable force but, with sufficient pressure in the opposite direction, is displaceable. Once the opposing force is removed, the nozzle means are automatically maneuvered or returned to their original position under the influence of the pressurized cooling medium. The influence against the piston member is released by the deactuation of the valve 52 which closes the supply of pressurized cooling medium to the piston chamber. As descibed, return of the needle cooler to an inoperative position may be effected under the influence of the spring 64 whereby the nozzle means are automatically removed from the sewing area thus providing operator access to the sewing area or zone. 
     Thus there has been provided, in accordance with the invention, a Sewing Machine Needle Cooler that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.