US2692620A - Method and apparatus for making double conical torsion springs - Google Patents

Description

Oct. 26, 1954 c. H. K. SJOBOHM 2,692,620

METHOD AND APPARATUS FOR MAKING DOUBLE CONICAL TORSION SPRINGS Filed Jan. 13, 1955 Y 3 Sheets-Sheet l FIEJZ lawentm': (027 H KfiJoaa/w,

Oct. 26, 1954 Filed Jan. 15, 1953 FIG. 2-

C. H. K. SJOBO METHOD AND APPARATUS FOR MAKING DOUBLE CONICAL TORSION SPRINGS 3 Sheets-Sheet 2 llllllillllllll IIIHIIIIIIIIIIIMWI lnveniors 6027/64 5J050HM,

Oct. 26, 1954 c. H. K. SJOBOHM 2,692,620

METHOD AND APPARATUS FOR MAKING DOUBLE CONICAL TORSION SPRINGS Filed Jan. 13, 1953 3 Sheets-Sheet :5

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Patented Oct. 26, 1954 UNITED STATES PATENT "OFFICE METHOD AND APPARATUS FOR MAKING DOUBLE 'CONICAL TORSION SPRINGS Curt -H. K. sjobohm, Worcester, Mass.

Application January 13, 1953, Serial 'No. 331,045

Claims. 1

This invention relates to a method and apparatus for making doubleconical torsion springs such as those which are used in spring doors. These springs have a reduced diameter'portion in the center and increase in diameter outwardly toward each end. Because of this reduced diameter central portion, it is necessary to have two opposed arbors so that the formed spring can be removed therefrom. It is also necessary to keep the arbors in close contact throughout the forming of the spring. For that reason, the apparatus used prior to myinvention required the use of a traveling or traversing wire feed and arbors which did not move axially durin the formation of the spring. Such apparatus formed the springs at a relatively slow rate, required a complicated mechanism and did'not form a spring of uniform pitch.

It is the object of my invention to provide apparatus for forming a double conical spring in which the wire is fed axially without traversing.

Another object is to provide such apparatus wh ch will form springs of uniform pitch at a rapid rate.

Still another object is to provide a method of forming double conical springs at a rapid rate.

These and other objects will be more apparent after referring to the following specifications and attached drawings, in which:

Figure 1 is a top plan view of the spring making apparatus;

Figure 2 is a vertical view taken on the line II-II of Figure 1;

Figure 3 is a view taken onthe line III-III of Figure 1, the upper portion of the coiling device being omitted except for the parts indicated by dotted lines Figure 4 is a viewof the arbors showing a wire fed thereto ready to be coiled;

Figure 5 is a view, similar to Figure 4, show-ing the spring partially coiled;

Figure 6 is a View, similar to Figure 4, showing the completed spring;

Figure 7 is an enlarged view, partly in section, showing details of the arbor; and

Figure 8 is a view, similar to Figure '7, showing the arbors in engagement.

Referring more particularly to the drawing, the reference 2 indicates the winding arbor which can be rotated by mechanism 3 such as shown and described in the patents to Sleeper Nos. 1,045,900 and 1,368,297. A winding pin 4 is mounted on the bottom of aspindle 5 which also supports the arbor 2. The pin 4 is spaced a short distance from the arbor 2 for 'a reason-which will appear later. The spindle '6 is reciproea'ted in the usual manner by mechanism 1 such as shown and 'described in the above mentioned patents. Wir'e-is fed in the usual manner through a wire cutters by feeding mechanism 9 such as shown and described in the above mentioned patents. A cutter blade ill (Figures 2 and 6) is mounted on a slide l2 which is reciprocated by means o'facam' I'd. A roller ['6 mounted on the slide l2cont'acts the cam I4 to move the slide -l 2 to cut the'wire. spring l1 retracts the slide t2. Thecam I4 is moun'ted'on a shaft is which is rotated in synchronism with the spindle feeding and rotating mechanism. A stop 20 is mounte'd'for movement toward and away from the arbor 2 on a slide 22.

Mounted beneath arbor 2 in alignment there- 'with is an arbor 24. As shown in Figure 2 the arbor 2 3 is resiliently attached to the piston rod 26 of an air cylinder 28 in the following manner. The piston rod 26 has an-axial opening 30 therein with a steel ball 32 mounted in the bottom thereof. A bushing 34 is mounted adjacent the ball 32. A collar 36 is provided on the arbor 24, the lower end of which is surrounded by a spring 38. The bottom end of the spring bears against the collar 35 and the top end against the bottom Of a nut 40 which is screwed into the opening 30. "The spring 35 cushions the shock of the contact between arbor 24 and the bushing 40 when the piston rod 26 reaches the bottom of its stroke. As shown in Figures 7 and 8 the top of the arbor 24" is provided with a spherical opening 42 for receiving a spherical portion M mounted on the bottom end of the arbor 2. Air is provided to the top of cylinder 28 through an air conduit 46 and to the bottom through a conduit '48. The end of'conduit 46 is attached to a control valve 50 and the end of conduit 48 to a control valv 52. The control valves 50 and 52 are mounted adjacent the shaft [8 and are provided with levers 54 and 56, respectively, which extend downward 'andare actuated by means of cams 58 and 60 mounted on the shaft l8. Air is provided to the valves '58 and 52 through air reducing valves-62 and 64, respectively.

The "operation of the device is as follows:

The arbor '2 is fed "downwardly until it almost reaches its lowest position, at which time the cams 58 and "60 will actuate the valve 53 and 52 to introduce air through the conduit 43, thus snapping the arbor '24 up against the arbor 2 with the spherical portion 44 being received in the 'opening 12. The arbor '2 continues its downward movement pushing the arbor 2! ahead of it against the pressure of theair in the cylinder 28 until it reaches the position shown in Figures 2 and 4. In this position the arbor 2 is stationary and the windin pin 4 is so positioned that the wire W which is being fed will pass between the winding pin 4 and the arbor 2. Movement of the wire continues until it abuts against the stop 20 as shown in Figure 4. The arbor 2 is then rotated and raised in the usual manner so that the coils of the spring S are formed. The air in cylinder 28 holds the lower arbor 24 against the upper arbor 2 at all times during the winding of the spring. After the spring S has been completely wound, the cam 14 moves the cutter blade it over the wire cutter 8 to sever the wire W at the desired point as shown in Figure 6. As soon as the wire W is severed the cams 58 and 6D operate the valves 55! and 52 so that air is delivered through conduit 48 to the top of cylinder 26, thus rapidly retracting the lower arbor 24 from its highest position as shown in Figure 6. This permits the spring S to be discharged. The machine is then ready to fabricate another spring.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. In apparatus for making a double conical spring from a length of wire, said apparatus having a rotatable reciprocating spindle, a conical arbor on the end of said spindle with its smallest diameter portion at the free end thereof, means for holding the end of said wire for rotary movement with said arbor, a second rotatable conical arbor in axial alignment with said first arbor, the smallest diameter portion of the second arbor facing the smallest diameter portion of the first arbor; the improvement comprising a stationary wire cutter adjacent said arbor through which wire is fed, a cylinder mounted in alignment with said arbors at the large diameter end of the second arbor, a piston in said cylinder, a piston rod connected to said piston, means connecting said second arbor to said piston rod, means for supplying a fluid to the outer end of said cylinder to hold said second arbor against said first arbor during formation of said spring, a cutting blade adapted to cooperate with said wire cutter to sever said wire when the spring is completed, and means for supplying a fluid to the inner end of said cylinder to retract said second arbor from said first arbor when the spring is completed and the wire out.

2. In apparatus for making a double conical spring from a length of wire, said apparatus having a rotatable reciprocating spindle, a conical arbor on the end of said spindle with its smallest diameter portion at the free end thereof, a pin mounted on the end of said spindle adjacent said arbor, the distance between said pin and arbor being sufficient to receive said wire, a second rotatable conical arbor in axial alignment with said first arbor, the smallest diameter portion of the second arbor facing the smallest diameter portion of the first arbor; the improvement comprising a stationary wire cutter adjacent said arbor through which wire is fed, a stop in alignment with said wire cutter for stopping axial movement of wire fed through said wire cutter and between said pin and arbor, a male member on the small diameter end of one of said arbors, a female member on the small diameter end of the other of said arbors, a cylinder mounted in alignment with said arbors at the large diameter end of the second arbor, a piston in said cylinder, a piston rod connected to said piston, means connecting said second arbor to said piston rod, means for supplying a fluid to the outer end of said cylinder to hold said second arbor against said first arbor during formation of said spring, a cutting blade adapted to cooperate with said Wire cutter to sever said wire when the spring is completed, and means for supplying a fluid to the inner end of said cylinder to retract said second arbor from said first arbor when the spring is completed and the wire cut.

3. Apparatus for making a double conical spring from a length of wire, said apparatus comprising a rotatable reciprocating spindle arranged with its axis vertical, a top conical arbor mounted on the bottom of said spindle with its smallest diameter portion at the lower end thereof, a pin mounted on the bottom of said spindle, the distance between said pin and arbor being sufiicient to receive said wire, a stationary wire cutter adjacent said arbor through which wire is fed, a bottom conical rotatable arbor in axial alignment with said top arbor, the smallest diameter portion thereof being at the top thereof, a cylinder mounted below said bottom arbor in axial alignment therewith, a piston in said cylinder, a piston rod connected to said piston, means connecting said bottom arbor to said piston rod, means for supplying a fluid to the bottom of said cylinder to hold said bottom arbor against said top arbor during formation of said spring, a cutting blade adapted to cooperate with said wire cutter to sever said wire when the spring is completed, and means for supplying a fluid to the top of said cylinder to retract said bottom arbor from said top arbor when the spring is completed and the wire cut.

4. Apparatus for making a double conical spring from a length of wire, said apparatus comprising a rotatable reciprocating spindle arranged with its axis vertical, a top conical arbor mounted on the bottom of said spindle with its smallest diameter portion at the lower end thereof, a pin mounted on the bottom of said spindle, the distance between said pin and arbor being sufficient to receive said wire, a stationary wire cutter adjacent said arbor through which wire is fed, a stop in alignment with said wire cutter for stopping axial movement of wire fed through said wire cutter and between said pin and arbor, a bottom conical rotatable arbor in axial alignment with said top arbor, the smallest diameter portion thereof being at the top thereof, a male member on the small diameter end of one of said arbors, a female member on the small diameter end of the other of said arbors, a cylinder mounted below said bottom arbor in axial alignment therewith, a piston in said cylinder, a piston rod connected to said piston, means connecting said bottom arbor to said piston rod, means for supplying a fluid to the bottom of said cyl nder to hold said bottom arbor against said top arbor during formation of said spring, a cutting blade adapted to cooperate with said wire cutter to sever said Wire when the spring is completed, and

' means for supplying a fluid to the top of said cylinder to retract said bottom arbor from said top arbor when the spring is completed and the wire cut.

5. The method of making a double conical spring on two opposed conical arbors having their small diameter ends facing each other which comprises feeding a wire axially past the large diameter end of the first of said arbors, gripping the fed wire to rotate with said first arbor, moving the second arbor against the first 5 6 arbor, rotating and retracting the first arbor in References Cited in the file of this patent a direction away from the second arbor to coil UNITED STATES PATENTS the wire therearound, resiliently moving the sec- Number Name Date ond arbor to hold it against the first arbor as 287 827 Fan NOV 6 1883 the first arbor rotates and retracts, c ntinuin 5 439513 f 1890 movement of both of said arbors with the arbors 502:968 g 1893 in engagement to 0011 the wire around both of 1345900 Sleeper Dec 3:1912 said arbors, stopping rotation of said arbors, cut- 32 03 Cunningham 23 1919 ting the formed spring from s id Wire, and r 10 1,368,297 Sleeper Feb. 15, 1921 tracting said second arbor from said first arbor 2,119,513 Peterson June 7, 1938 to permit removal of said spring. 2,406,130 Boyce Aug. 20, 1946

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