US2794477A

US2794477A - Method and apparatus for making coiled springs

Info

Publication number: US2794477A
Application number: US335302A
Authority: US
Inventors: Curt H K Sjobohm
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-02-05
Filing date: 1953-02-05
Publication date: 1957-06-04
Anticipated expiration: 1974-06-04

Description

June 4, 1957 c. H. K; SJOBOHM 2,

METHOD AND APPARATUS FOR MAKING COILED SPRINGS Filed Feb. 5, 1.953 4 Sheets-Sheet l V N Inventor:

6027 /i/(. 5J050HM,

Julie 1957 c. H. K. SJOEOHM' 2,794,477

METHOD AND APPARATUS FOR MAKING COILED SPRINGS Filed Feb. 5, 1953 4. Sheets-Sheet 2 w 1* 1.5 E wmmfi x w Er Em c Qw June 1 1957 c. H. K. SJOBOHM 2,794,477

METHOD AND APPARATUS FOR MAKING COILED SPRINGS 4 Sheets-Sheet 4 Filed Feb. 5, 1953 w momma .35, (0B7 HA. 5/050/7M United States Fatent C METHOD AND APPARATUS non MAKING COILED srnmes Curt H. K. Sjohohm, Worcester, Mass.

A Application February 5, 1953, Serial No. 335,302

9 (Ilaims. (Ci. 153-2) This invention relates to apparatus for making coiled springs and more particularly to torsion springs. Somewhat similar apparatus is shown in the patent to Sleeper No. 1,368,297. However, the apparatus shown there is not suitable for making particular types of torsion springs in one operation, and particularly it is not suited for making a torsion spring in which one end of the wire of the spring extends substantially parallel to the axis of the spring and at the same radial distance as the coils and the other end extends substantially perpendicular to the axis of the spring and outwardly from the coils of the spring. It is also not adapted for making springs in which one or more of the end convolutions are formed at right angles to the axis of the spring.

It is therefore an object of my invention to provide apparatus for making a large variety of types of torsion springs.

Another object is to provide such apparatus in which means are provided for squaring the ends of the spring.

Still another object is to provide such apparatus having means for feeding the wire to the coil mechanism with extreme accuracy.

A further object is to provide a method of making a torsion spring.

This and other objects will be more apparent after reference to the following specification and attached drawings, in which:

Figure 1 is a top plan view of the machine of my invention with parts removed for clarity;

Figure 2 is a side view of the machine of Figure 1;

.Figure 3 is a front view of the machine of Figure 1;

Figure 4 is a sectional view taken on the line IV-IV of Figure 2;

Figure 5 is an enlarged view of a detail of my invention;

Figure 6 is a sectional view taken on the line VIVI of Figure 1; and

Figure 7 is a view of a spring manufactured by the machine of my invention;

Figure 8 is a bottom plan view of the spring of Figure 7;

Figure 9 is a view taken on the line IX-IX of Figure 2;

Figure 10 is an enlarged view showing the leading end of the spring wire being bent; and

Figure 11 is an enlarged plan view showing the cutting and bending of the trailing end of the spring wire.

Referring more particularly to the drawings, the reference numeral 2 indicates a stand for supporting the machine of my invention. A gear 4 is attached to a shaftv 6 which is rotatably mounted on the stand 2. Power for rotating the gear 4 is provided from any suitable source. The face of the gear 4 is provided with diametrical guideways 8 for adjustment therein of a head 10 which carries a crank pin 12. One end of a connecting rod 14 is connected to the crank pin. The other end of the connecting rod 14 is pivotally connected to a slidable rack 16 which is guided in a horizontal path by means of suitable slideice ways on the supporting stand 2. The stroke of the sliding rack may be varied by adjusting the position of the head 10 in the guideways 8. The teeth of the rack 16 are in mesh with the teeth of a pinion 18 which is mounted on a vertical shaft 20. A large gear 22 is rotatably mounted on the top of the shaft 20 and is driven by means of a clutch 24, such as the one shown in the patent to Thomas No. 1,935,137. A stop 26 is mounted on a periphery of the gear 22 and is adapted to contact a stop 28 which is pivotally mounted on a pin 30. The gear 22 is in mesh with an elongated pinion 32. The pinion 32 is secured to a vertical spindle 34 which is slidably journaled in bearings 36. A spring winding arbor 38 is attached to the bottom of the spindle 34. A vertical hole 40 is provided in the end of the spindle 34 adjacent its connection to the arbor 38.

Instead of reciprocating the spindle 34 in the manner described in Sleeper Patent No. 1,368,297, the drive is provided with a squaring attachmentand auxiliary lifting attachment as described below.

A member 42 is attached to the rack 16 for reciproca tion therewith. A stud or bolt 44 passes through member 42 and carries a U-shaped pitch shell 46 which is attached to the back of member 42. The pitch shell 46 is adapted to occupy various positions of angular adjustment with respect to member 42 so that the pitch of the spring coils can be varied. For this purpose the shell 46 is pivoted about the bolt 44 and is held in adjusted position by means of a bolt 48 which passes through a slotted opening in the member 42. As best shown in Figures 4 and 5 the lower end of a grooved pitch cam 50 is received between the legs of the shell 46 and is pivotally connected to reciprocating bar 52 by means of a pin 54 received in the cam groove. The cam 50 is pivotally fastened to the shell 46 by means of a screw 56 and is held in floating position by means of four springs 58. Additional holes 59 through the

members

46 and 50 enable them to be rigidly fastened together when it is not desired to square the ends of the spring being formed. The reciprocating bar 52 has a pin 60 attached to its upper end. The pin 60 floats in slots 62 in a terminal fitting 64 attached to the end of pitch arm 66. Screws 68 are threaded into members 64 to provide stops for limiting the movement of pin 60 and bar 52. A spring 70 surrounds the reciprocating bar 52 with one end abutting against the lower part of fitting 64 and the other end bearing against a pin 72 mounted on the reciprocating bar 52. A collar 74 which serves as an abutment is at tached to the reciprocating bar 52 and is provided with two openings, one at each end thereof, for receiving screws 78 which are mounted on a stationary guide 80 for reciprocating bar 52. Nuts82 and 84 are provided on the screws 78 and serve as stops to limit movement of the collar 74. The pitch arm 66 is pivotally mounted intermediate its length on a pin 86. The other end of the arm 66 is pivotally connected to the spindle 34. A link 88 has one end slidably attached to the arm 66 and the other end attached to the pivoted stop 28. A lever 90 attached to the pin 30 has its free end pivotally connected to a link or arm 92. The other end of link 92 extends toward the shaft 6 and has a bifurcated block or yoke 94 attached thereto which surrounds the shaft. A collar 95 is attached to the shaft 6 at one side of yoke 94. Cams 96 and 98 are fastended to the shaft 6 by means of set screws and are provided with high and low cylindrical surfaces. The purpose of cam 96 will appear later. The cam 98 is provided with a high portion which is adapted to engage a roller 100 mounted on a pin 102 attached to the yoke 94. The collar 95 and cam 98 cooperate to prevent the yoke 94 from moving sidewise.

A bevel gear 106 is mounted on the free end of shaft 6 and is in mesh with a similar bevel gear 108 mounted on a rotatable shaft'110 which extends toward the front of the machine. A cam 112'is mounted on the shaft 110 intermediate its length. A bracket114 for thewire feeding'mechanism is attached tojthe supporting frame 2 adjacent the cam 112. A stationary spacer block 116 is mounted on the bracket 114. The base 118 of the wire feed is slidably mounted on the block 116 for movement toward and away from 'the front of the machine. An extension 119 is bolted 'to therear'of base 118. and carries a roll.120 which is adapted to be contacted'by the cam 96. The extension 119 is slidable in aguide 121 mounted on stand 2. A pinion 122 is mounted on the base 118 and meshes with a stationary rack '1-24 and a movable rack 126 which is connected to a slide .128. The rack 124 is supported by brackets 129 which are mounted on stand 2. The cam 112 is adapted to contact a roller 130 which is connected to the free end of a pivotally mounted arm 132. An adjusting screw 134 is also mounted on the arm 132 and passes through an opening in bracket 114. The screw 134 presses against a swinging bar 136 which is mounted for movement about a horizontal axis. The lower end of the bar 136 contacts the roller 135 at the end of the arm 137 of a cam 138 which is mounted on the siide 128 by means of a bolt 133. This moves earn 138 against a gripping jaw 140, thus clamping wire W against a stationary die 141. A, spring 142 urges the jaw 140 against its'cam 138. A plate 143 fastened to slide 128 holds the jaw 140 down against slide 128. The

parts

142 and 143 are omitted from Figure l for reasons of clarity. When the slide 128 has traveied the desired distance the cam 112 is so positioned that both the lever 132 and the arm 137 can move outwardly by means of the pressure of a compression spring 144 having one end attached to the arm 137 and the other end to the slide 128, thus releasing the'wire' and allowing it to travel freely while the spring S is being wound on the arbor. A spring 144a attached to the frame 2 retracts the slide 118 when the low spot on cam 96 is reached. The wire W being fed passes through apparatus 145 which permits the wire to feed forwardly but prevents backward movement thereof. Apparatus suitable for this purpose is shown in the patent to Delihanty No. 1,026,567.

A gear 146 is mounted on the forward end of shaft 116 and is in mesh with a gear 148 mounted thereabove on a shaft 149. Two

cams

150 and 151 are mounted on the shaft 149 and are adapted to be contacted by

rollers

152, 153, 154 and 155 which are mounted on pivotally mounted

levers

156, 157, 158 and 159, respectively. The

levers

156 and 157 areconnected by a spring 160 and levers 1'53 and 159 by a spring 161. The lever 156 has a slide 162 attached thereto which has its end shaped to form the male portion of the cutter and end forming mechanism. The lever 157 has a slide 163 attached thereto which is shaped to form the female portion of the cutter and end forming mechanism. The lever 159 has a slide 164 attached thereto by means of linkage 159a. V The end of the slide 164 is provided with a bending tool 165. A vertical slot 166 is provided in the front face of a pipe cutter or cut on bushing 167 through which the wire W passes, and across the slotted end face of which the shaped end of slide 162 moves in performing the cutting operation. No novelty is claimed for this tool reciprocating'mechanism since it is old as shown in the patent to Blount and'lhomas No. 2,085,570 and not part of applicants' invention. The lever 153 is not used except as an anchor for the spring 161 in the present invention, but may be used to operate a fourth slide when the machine is being used for other purposes.

The operation of the machine is as follows: 7 Assume that the wire W is being fed to the coiler and that a spring 8, such as'shown in Figure 7is being formed. One end 17 or" the'spring extends at right angles to the top coil of thespring and the other end 172 is bent radi'a'lly outward from the bottom coil of the spring. The

gear 4 continuously rotates shafts 6 and 110. After the end 172 of one formed spring is cut off, the arbor 38 will have moved to its lowest position. The first step in the formation of the spring is the formation of the bend 170 in the end of the wire. This is accomplished by the slide 164 moving upwardly and the tool 165 bend- 'ing the end of the wire upwardly into the slot 166 in the pipe cutter 167 as best shown in Figure 10. The cam 112 has reached a position where it moves the roller 136 inwardly, thus causing the screw 134 to bear against the swinging bar 136 which, in turn, moves the cam 138 against the jaw 140. This clamps the wire W between the jaw and die 141 so that the wire cannot move longitudinally or rotate about its axis. Roller 120 is also in contact with cam 96. In the meantime, cam 98 has contacted roller 100 which moves the arm 92 to rotate the lever 91) and cause link 88 to pull downwardly on pitch arm 66, thus moving the arbor 38 up out of the path of movement of the bent end 170 of the wire W. This movement is independent of the regular movement of the arm 66 caused by the pitch cam 50 and is made possible by the lost motion connection between the reciprocating bar 52 and pitch arm 66. As the pitch arm 66 is pulled downwardly by link 38, the slots 62 permit the bottom stop 68 to move away from the pin 60. The movement is limited by the top stop 68 when one is provided. However, the top stop is not a necessity. With the arbor 38 up out of the way, the wire W is fed a short distance until it is positioned accurately under the hole 40. This is done by means of cam 96 which moves slide 113 with gear 122 mounted thereon. The gear 122 will rotate in mesh with rack 124 and 126 and 7 cause the rack 126 to move the slide 128 and the wire W accurately for a short distance. The continued rotation of gear 4 moves cams 96,98 and 112 beyond their high spots so that the wire W is unclamped-and the link 83 is free to move. The wire W is prevented from moving rearwardly by the device 145, but is free to move forwardly' Also in the meantime, the stop 26 moves against pivoted stop 28, which at this portion of the spring forming cycle is stationary and in its lower position, thus positioning the hole 40 in accurate position to receive the bent end 170. After pressure on the link 88 is removed, the spring 70 forces pitch arm 66 upwardly until the lower stop 68 contacts pin 60. This movesjthe spindle 34 downwardly and positions thewire end 170 in the hole 40. The gear 22 then rotates in a counterclockwise direction as seen in Figure 1 to rotate the arbor 38. At the same time the arbor 38 is moved upwardly by the pitch lever 52. The combined rotation and upward movement of the arbor 38 pulls wire from the supply coil and' forms the convolutions of the spring S.

The coils at either or both ends may be made square; that is, at right angles to the axis of the spring in the following manner: Adjacent the end of the stroke of the rack 16 with the pitch shell 46 mounted thereon, the collar 74 will strike nuts 82 or 84, depending upon the direction of travel, and stop the movement of reciprocating bar 52 while the arbor 38 is rotating and forming either the first or last coil of the spring S. Thus, there will be no feed of the arbor for these coils and they will be square. This is made possibleby the use of the pivoted pitch cam 50 and springs 58 which permit movement "of the cam 50 with respect to the pitch shell 46. If squaring of only one end of the spring is desired, the springs above or below the cam 50 and'oh'e pair of stop nuts 82 or 84 may be omitted depending upon the end of the spring which is being squared;

When all the coils are formed in the spring, the cam 150,

rollers

152 and 153, and spring will move the

levers

156 and 157 toward each other, thus causing the

slides

162 and 163 to move toward each other. The shaped end of slide 162 moves across the end face of cut off -bushing 162, thus cutting the wire W to the desired length and forming the end 172 on the spring as shown in Figure 11. The machine is then ready to form another spring. v

All of the attachments need not be used at one time, but some may be used without the others depending upon the type of spring being made. For example, the squaring attachment will not be used unless the ends of the spring are to be squared and the auxiliary lifting attachment will not be used unless it is necessary to move the arbor up out of the path of movement of the end of the wire or spring. However, for universal use all attachments should be provided on the machine.

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

I claim:

1. A machine for making helical springs comprising a rotary arbor and means for automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar, a floating connection between said reciprocating bar and the other end of said pitch arm, means for reciprocating said reciprocating bar, and separate means automatically operable to move said reciprocating bar with respect to said pitch arm a distance permitted by said floating connection when said arbor is adjacent one end of its path of travel.

2. A machine for making helical springs comprising a rotary arbor and means for automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar, means for reciprocating said reciprocating bar, said pitch arm having an elongated slot therein at the other end thereof, a pin mounted on one end of said reciprocating bar and slidable in said slot, :a spring urging said pitch arm away from the other end of said reciprocating bar, and separate means automatically operable to move said pitch arm against the pressure of said spring when said arbor is adjacent one end of its path of travel.

3. A machine for making helical springs comprising a vertical rotary arbor and means for automatically raising and lowering said arbor; said means including a substantially horizontal pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a substantially vertical reciprocating bar, means for reciprocating said reciprocating bar, said pitch arm having a substantially vertical elongated slot therein at the other end thereof, a pin mounted on the upper end of said reciprocating bar and slidable in said slot, a spring urging said pitch arm upwardly with respect to said pin, and separate means automatically operable to move said pitch arm downwardly against the pressure of said spring to move said arbor upwardly when it has reached the lowest part of its path of travel.

4. A method of making a helical wire spring having one end of the wire extending substantially parallel to the axis of the spring at the same radial distance as the coils of the spring, which method comprises feeding a length of wire horizontally toward a vertical spring winding arbor, bending the end of the wire upwardly, raising the arbor to a level where it can clear the top of said bent wire, feeding the wire with the bend in a vertical plane to a position directly beneath a vertical hole in the raised arbor spindle, then lowering the spindle until the bend is in said hole, rotating and simultaneously raising the arbor to form the coils of the spring, and then cutting the formed spring from the length of wire.

5. A method or" making a helical wire spring having one end of the wire extending substantially parallel to the axis of the spring at the same radial distance as the 6 coils of the spring, which method comprises feeding a length of wire horizontally toward a vertical spring winding arbor, bending the end of the wire upwardly, raising the arbor to a level where it can clear the top of said bent wire, feeding the wire with the Bend in a vertical plane to a position directly beneath a vertical hole in the raised arbor spindle, then lowering the spindle until the bend is in said hole, rotating and simultaneously raising the arbor to form the coils of the spring, continuing rotation of said arbor while holding it from raising during the formation of the last coil of the spring whereby the last coil is formed perpendicular to the axis of the spring, and then cutting the formed spring from the length of wire.

6. A machine for making helical springs comprising a rotary arbor and means for automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar having one end connected to the other end of said pitch arm, a cam having a groove therein arranged obliquely of the path of movement of said reciprocating bar, means connected to the other end of said reciprocating bar and slidably mounted in said groove, a pitch shell, means slidably mounting said pitch shell, means for reciprocating said pitch shell transversely of the path of movement of said reciprocating bar, means pivotally connecting said cam to said pitch shell for movement therewith, a stop, means for supporting said stop adjacent said reciprocating bar, an abutment mounted on said reciprocating bar for movement therewith into engagement with said stop, and resilient means permitting limited movement of said cam about its pivotwhen said abutment strikes said stop for preventing reciprocation of said arbor by said pitch arm during said limited movement of said cam about its pivot, thereby squaring [an end of a helical spring.

7. A machine for making helical springs comprising a rotary arbor and means for automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar having one end connected to the other end of said pitch arm, a cam having a groove therein arranged obliquely of the path of movement of said reciprocating bar, means connected to the other end of said reciprocating bar and slidably mounted in said groove, a pitch shell, means slidably mounting said pitch shell, means for reciprocating said pitch shell transversely of the path of movement of said reciprocating bar, means pivotally connecting said cam to said pitch shell for movement therewith, a pair of stops spaced apart axially of said pitch lever, means for supporting said stops adjacent said reciprocating bar, an abutment mounted on said reciprocating bar for movement therewith into engagement with said stops, and resilient means permitting limited movement of said cam about its pivot when said abutment strikes either of said stops for preventing reciprocation of said arbor by said pitch arm during said limited movement of said cam about its pivot, thereby squaring the ends of a helical spring.

8. A machine for making helical springs comprising a rotary arbor and means for automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar, a floating connection between said reciprocating bar and the other end of said pitch arm, a cam having a groove therein arranged obliquely of the path of movement of said reciprocating bar, means connected to the other end of said pitch lever and slidably mounted in said groove, a pitch shell, means slidably mounting said pitch shell, means for reciprocating sai'd pitch shell transversely of the path of movement of said reciprocating bar, means pivotally connecting said cam to said pitch shell for movement therewith, a stop, means for supporting said stop adjacent said reciprocating bar, an abutment mounted on said reciprocating bar for movement therewith into engagement with said stop, resilient means permitting limited movement of said cam about its pivot when said abutment strikes said stop for preventing reciprocation of said arbor by said pitch arm during said limited movement of said 'cam'about its pivot, thereby squaring an end of a helical spring, and separate means automatically operable to move said pitch lever with respect to said pitch arm a distance permitted by said floating connection when said arbor is adjacent one end of its path of travel.

9. A machine for making helical springs comprising a rotary arbor and meansfor automatically reciprocating said arbor in an axial direction; said means including a pitch arm, means for pivotally supporting said pitch arm intermediate its ends, a connection between one end of said pitch arm and said arbor, a reciprocating bar, a cam having a groove therein arranged obliquely of the path of movement of said reciprocating bar, means connected to one end of said reciprocating bar and slidably mounted in said groove, a pitch shell, means slidably mounting said pitch shell, means for reciprocating said pitch shell transversely of the path of movement of said reciprocating bar, means pivotally connecting said cam to said pitch shell for movement therewith, a stop, means for supporting said stop adjacent said reciprocating bar, an abutment mounted on said reciprocating bar for movement therewith into engagement with said stop, resilient means permitting limited movement of said cam about its pivot when said abutment strikes said stop for preventing reciprocation of said arbor by said pitch -arm during said limited movement of said 0am about its pivot, thereby squaring an end of a helical spring, said pitch arm having an elongated slot therein at the other end thereof, a pin mounted on the other end of said pitch lever and slidable insaid slot, a spring urging said pitch tarm away from the first named end of said reciprocating bar, and separate means automatically operable to move said pitch arm against the pressure of said spring when said arbor is adjacent one end of its path of travel.

References Cited in the file of this patent UNITED STATES PATENTS 1,026,567 Delihanty May 14, 1912 1,368,297 Sleeper Feb. 15, 1921 1,382,379 Olson June 21, 1921 1,436,678 Pitman Nov. 28,1922 1,778,559 Kondakjian Oct. 14, 1930 1,828,413 Holmes Oct. 20, 1931 1,857,860 Nigro May 10, 1932 1,935,137 Thomas Nov. 14, 1933 1,973,667 Sleeper Sept. 11, 1934 1,999,654 Cobb Apr. 30, 1935 2,049,914 Lewis Aug. 4, 1936 2,085,570 Blount June 29, 1937 2,092,899 Tondeur Sept. 14, 1937 2,119,513 Peterson June 7, 1938 2,163,019 Blount June 20, 1939 2,190,805 Shook Feb. 20, 1940 2,612,796 Bastian Oct. 7, 1952 I FOREIGN PATENTS 329,175 Germany Nov. 16, 1920 202,110 Great Britain Aug. 16, 1923 563,798 Great Britain Aug. 30, 1944