US3139136A

US3139136A - Retractable holding means for squaring flat end of spring stock on coiling machine

Info

Publication number: US3139136A
Application number: US84295A
Authority: US
Inventors: Isaac M Chambers
Original assignee: HENRY MILLER SPRING AND Manufacturing CO
Current assignee: HENRY MILLER SPRING AND Manufacturing CO
Priority date: 1961-01-23
Filing date: 1961-01-23
Publication date: 1964-06-30
Anticipated expiration: 1981-06-30

Description

June 30, 1964 1. M. CHAMBERS 3,139,136

RETRACTABLE HOLDING MEANS FOR SQUARING FLAT END OF SPRING STOCK ON- COILING MACHINE Filed Jan. 25. 1961 3 Sheets-Sheet 1 INVENTOR. I 5AACMC'HAM6E25 HIJA rmeusv June 30, 1964 1 M. CHAMBERS 3,139,136

RETRACTABLE HOLDING MEANS FOR SQUARING FLAT END OF SPRING STOCK ON COILING MACHINE Filed Jan. 23, 1961 Y 3 Sheets-Sheet 2 IN VEN TOR. JIsMcM. CHAMEEES H15 A r TGRNEY June 30, 1964 (:HAMBERS 3,139,136

RETRACTABLE HOLDING MEANS FOR SQUARING FLAT END OF SPRING STOCK ON COILING MACHINE Filed Jan. 23, 1961 3 Sheets-Sheet 5 I N V EN TOR. [.54 AC M C'HA Mae/es United States Patent RETRACTABLE HOLDING MEANS FOR SQUAR- IN G FLAT END 0F SPRlNG STOCK 0N CGILTNG MACHINE Isaac M. Chambers, OHara Township, Allegheny County,

Pa., assignor to Henry Miller Spring and Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Jan. 23, 1961, Ser. No. 84,295 13 Claims. (Cl. 153-67) This invention relates generally to the method and apparatus for making heavy hot wound helical springs and more particularly to a machine for flattening and holding of the hot tapered face of the gauged bar end before it is clamped in position for Welding.

Compression springs made from hot wound bars have both ends of the bar forge tapered to a blunt chisel point. This is done to provide a fiat bearing on the ends of the finished spring. Present practice is for a coiler to pick up the back end of the hot bar with a pair of tongs and place the front end of the bar on the mandrel, against a stop pin and under the clamp. The squareness of the tapered bar end with relation to the chuck face is controlled by the coiler sighting along the bar. Such a practice is a hit or miss method, and frequently results in concave or convex ends on the finished spring. A spring with this type of end will lean when stood on end and will be subject to rejection by the customers inspectors, unless ground square. This is a costly operation. An important object of this invention is to eliminate such loss and expense by the application of a bar positioner. Thousands of springs made with this bar positioner have shown front end squareness that will pass the AAR specification for ground ends springs without the latter operation.

Spring coiling machines such as disclosed in the United States Gogan Patent 2,018,209 of October 22, 1935, attempted to solve this problem by employing a rocker arm type of clamp bar. This rocker arm was put out on machines and was found to be unsuccessful and had to be replaced by a radially movable clamp bar which is used to this day on these coiling machines. These machines have a coiling lead screw in front of and slightly above the mandrel around which the hot bar is formed into a coil. The operator is required to push the flat end of the chiseled pointed hot bar against the stop pin on the normally disposed chuck face and twist the hot bar until the flat is against this normal surface before closing the clamp that holds the hot bar on the mandrel. The rocker arm type of clamp bar was supposed to force the flat of the taper against the face of the chuck at the same time that it clamped the bar to the mandrel but it failed to accomplish this purpose.

The principal object of this invention is the provision of a mechanism that squares the spring fiat against a surface normal to the mandrel and holds the same in this position until the clamp bar secures the hot bar to the mandrel. By initially squaring the spring fiat against a surface that is normal relative to the mandrel, such as the chuck face before and during the clamping operation, the clamping bar will retain the hot bar in its proper position for the initial coiling of the helical spring. As soon as the bar is clamped to the mandrel the squaring device is retracted to permit the spring to be rolled around the mandrel in the usual way and when the opposite end of the spring approaches the mandrel the operator has to give the hot bar a twist so as to insure that the trailing flat of the helical spring will be squared against its normally disposed forming surface which in most instances is the stripping plate.

Although a machine is shown for performing this function a second operatormay stand in the back of the ma- 3,139,136 Patented June 30, 1964 chine and by means of a chiseled pointed rod could force the flat against the face of the chuck which is normal or at right angles to the mandrel. This is rather costly and in view of the discharging device for the springs coming from the machine it is rather difficult to position a second operator to perform this work. The first operator standing in front of the machine cannot see too well owing to the fact that the lead screw together with the hot bar itself are in the path of vision.

Another object is the provision of a bar positioning arm actuated by a power cylinder for squaring the fiat of a hot bar against a face normal to the mandrel when the fiat end of the chiseled pointed hot bar is against the stop pin and on the mandrel. The positioning bar is actuated by a power cylinder which will release the same after a clamp bar clamps the chiseled ended hot bar in proper position on the mandrel. This object also contemplates a circuit for actuating the positioning bar in combination with the bar clamp to properly align the chiseled pointed hot bar preparatory to coiling the same about the mandrel.

Another object is the provision of a new method and apparatus for engaging the chiseled pointed hot bar on the stock side of the bar clamp for the purpose of squaring the chiseled flat against a surface normal to the mandrel on which the helix is formed.

Other objects and advantages of this invention appear hereinafter in the following description and claims.

The accompanying drawings show for the purpose of exemplification without limiting this invention or the claims thereto, certain practical embodiments illustrating the principles of this invention; wherein FIG. 1 is a view in front elevation of a spring coiling machine containing this invention.

FIG. 2 is an enlarged plan View of the bar positioner as applied to the machine with parts broken away.

FIG. 3 is an enlarged plan view of the bar positioner and its operating cylinder.

FIG. 4 is an enlarged sectional view showing the bar positioner as illustrated in FIG. 2.

FIG. 5 is an enlarged view in elevation of the rear of the spring coiling machine containing this invention.

Referring particularly to FIG. 1 a bed or base 1 of the machine extends for the full length thereof and supports the gear housing 2 at one end on which is mounted the motor 3 having a V-belt drive 4 to supply power to a gear train within the gear housing 2. The main drive from the gear housing is on the centerline .5 which supports the rotating air cylinder 6 on one side of the gear case 2 and the intermediate chuck centering air cylinder indicated at 7 to actuate the chuck detent 8 operating on the chuck member 10 on the main shaft. This mechanical interlock for the chuck to pre-position the stop pin on the face of the chuck may be replaced by other suitable means for stopping the shaft 11 at the proper position so that the stop pin is in position to receive the blunt end of the chisel of the rod bar when the bar clamp is above the latter. The chuck member 12 is mounted on the shaft 11 and supports the free end of the mandrel 13 the opposite end of which is supported by the slide assembly and it passes through the stripper bracket 14 having a stripper face plate 15 through which the mandrel 13 is withdrawn by the stripper slide assembly 16. The slide assembly is carried by the overhead beam 17 and is actuated by the stripper air cylinder 18. The overhead beam 17 is supported at its right end by the brackets 20 on the gear case 2 and the left end is supported by the bracket 21 mounted on the left end of the bed 1. A pair of lead screw brackets 22 and 23 are supported from the bridge 17 for the purpose of rotatably supporting the lead screw 24 which is of opposite hand to that of the helical coil being formed and is rotated in the direction opposite to that of the mandrel so that the shaft in the gear case'2 rotates the lead screw so that the surface speed of the lead screw and the surface speed of the mandrel function to properly aid in allowing the hot bar to feed onto the mandrel in forming the spring.

The mandrel 13 has a squared end where it enters the chuck 12 which drives the same when it is extended as shown in FIG. 1. When the mandrel 13 is retracted to strip the spring it is not rotated and when it is returned it ordinarily is in the same position so that it has no difficulty in having its squared end enter the socket in the chuck. It is common practice to rotate the mandrel 13 by hand every day for at least ninety degrees so as to provide uniform wear on the mandrel surface.

The machine frame, the housing 2, the bridge member 17 and the lead screw 24 are all admitted in the detailed showing in FIG. 1 and the mandrel 13 is shown to be in position within the chuck 12. The chuck face 27 is at right angles or normal to the axis of the mandrel and chuck and this face carries the stop pin 28 which is beyond the center of the mandrel when the bar clamp Ed in the chuck 12 is at top dead center as shown in FIG. 2. The spring bar stock 31 is of course hot and its taper starts at 32 on both sides of the bar stock. As illustrated in FIG. 4 this taper runs for the full depth of the bar stock at point 33. As shown in FIGS. 2, 3 and 4 the bar stock has its blunt end fitted against the stop 28 and the bar positioning arm 34 having its contacting lug 35 in engagement with the flat 32 of the bar stock 31 holding the same flat against the normal surface 27. The contact lug 35 is welded to the arm 34 and has a cylindrical surface 36 so as to provide aligned contact against the flat of the hot bar 31. It would be noted that this line contact extends on the stock side of the center 5 in relation to the bar clamp 30. Thus the greatest area and heaviest portion of the bar stock is engaged by the button 35 which insures the squaring of the flat of the bar stock against the normal face 27. While this bar is thus held tightly by the button 35 the clamp 36 is energized to tightly clamp the bar stock against the top surface of the mandrel 13.

The clamp 30 operates in a radial slot in the chuck V 12 and has on its rear face a rack operated by a gear sector which in turn is actuated by an air operated pull rod. The clamping face of the clamp bar extends be yond the radial or normal face 27 and is roughened. Thus when the clamp 30 is actuated it moves radially inwardly to engage the bar stock and clamp the same in position while the stock is held fiat against the face 27 of the chuck. 1

As shown in FIG. 4 the clamping face of the clamp bar 30 is provided with teeth that tightly grasp the hot metal to clamp it in place. A' circuit is provided to permit the arm 34 to be retracted to the position shown in dotted lines in FIG. 2 after the bar clamp 30 has tightly engaged the work.

The arm 34 is keyed to the shaft 57 rotatably supported by the spaced bearings 38 in the bracket 40 secured to the bridge member 17.

The upper end of the shaft 37 has secured thereto the i arm 41 which is locked by means of a key so that it is fixed relative to the shaft in the same manner as that of the arm 34. The outer end of the arm 41 is pivoted as at 42 to the outer end of the piston 43 that operates in the double acting power cylinder 44. The other end of the powercylinder 44 is supported by the pivot 45 to the bracket member 16 that is also secured tov the bridge member 1'7 as shown in FIGS. 3 and 5. The upper end of the shaft 37 carries a cam 47 for actuating the switch member 48.. This cam closes the switch member 48 only when the arm 34- is in its retracted position as shown in FIG. 2.

a A circuit is provided to be controlled by the switch 48 to prevent the rotation of the chuck and the lead screw only after the bar positioning arm 34 is in its retracted position. This interlock prevents any interference between the arm 34 and the next succeeding turn of the coil being formed.

The switch 48 also is provided with an interlocking contact which is closed by the cam 47 when the arm 34 is in the position as shown in full lines in FIG. 2 for the purpose of squaring the flat surface of the bar stock 31 against the face 27 after which the circuit permits the bar clamp St! to be energized to clamp the stock in position on the mandrel. Thus the switch 48 functions to interlock with two circuits one to insure that it is withdrawn before the machine is started and the other to insure that the bar stock is squared against the chuck face before the bar clamp 30 securely clamps the same against the mandrel.

A roller 56 is rotatably supported by the bracket member 51 adjustably secured to the under side of the bridge member 17 and is positioned so as to, be closely adjacent the stripper plate 15 as shown in FIG. 5. The roller is provided with a cylindrical surface 52 and a tapered surface 53. As the hot bar stock is rolled into coiled form on the mandrel 13 and approaches the roller 50 the heavy or rounded portion of the bar stock comes into engagement with the tapered surface 53 at which time the operator gives the bar stock a twist to counteract the constant attempt for the helical rolling surfaces to twist the bar stock which countertwist allows the roller 50 to position the chiseled tapered stock so that its flat face engages the flat face of the stripper plate 15.

I claim:

1. A spring Winding machine having a rotary chuck with an open chuck throat, a transverse flat face on said chuck normal to the rotary axis of said chuck, a

spaced relation to said chuck face and having an opening aligned with said chuck throat, a rotatable mandrel.

supported on said machine to slide axially and pass through said stripping plate opening into said chuckthroat to be rotated thereby, a stop on said chuck flat face, a clamp on said chuck operable transversely of said flat face and radially of said mandrel to hold spring bar stock on said mandrel, the spring bar stock having a flattened side adjacent its end, and a holding means supported from said machine and positioned to operate substantially normally to said fiat face to engage the spring bar stock and hold its flattened side against said chuck fiat face when said clamp is closed to clamp the spring bar stock on said mandrel.

2. The spring winding machine of claim 1 characterized in that said clamp is positioned between said stop and said holding means. 1

3. The spring winding structure of claim 1 characterized in that said stop, clamp and holding means are triangularly disposed relative to said chuck flat face with the clamp at the apex.

4. The spring winding machine of claim 1 characterized in that said holding means applies its holding force to the bar stock at right angles to the application of the clamp force.

5. The spring winding machine of claim 1 character ized by control means to interlock the operation of said holding means to close and hold the spring bar stock before the operation of said clamp and to release said holding means before rotating'said mandrel.

6. The spring winding machine of claim 1 characterized in that said holding means is an arm pivotally supported on a vertical axis to swing into position over said mandrel, and a motor means to swing said arm and apply holding forces and to retract said arm from said mandrel.

7. The spring winding machine of claim 6 characterized in that said motor means is a fluid motor.

8. The spring winding machine of claim 7 characterized in that said fluid motor is double-acting.

9. A spring winding machine having a rotary chuck with an open chuck throat, a transverse flat face on said chuck normal to the rotary axis of said chuck, a stripping plate having a flat face in parallel opposed spaced relation to said chuck face and having an opening aligned with said chuck throat, a rotatable mandrel supported on said machine to slide axially and pass through said stripping plate opening into said chuck throat to be rotated thereby, a stop on said chuck flat face, a clamp on said chuck operable transversely of said flat face and radially of said mandrel to hold spring bar stock on said mandrel, and holding means supported from said machine and positioned to operate substantially normally to said fiat face to engage the spring bar stock and hold it against said chuck flat face when said clamp is closed to clamp the spring bar stock on said mandrel.

10. A machine for winding a coil spring from bar stock having a flattened side adjacent its end consisting of a base supporting a rotary member having a central opening and a flat face adjacent said opening, a rotary mandrel reciprocably mounted on said base to be extended into said central opening and retractable therefrom, means to rotate said rotary member and said rotary mandrel, a clamp supported to rotate with said rotary member and extended and operable transversely of said flat face and radially of said mandrel, a stop on said rotary member adjacent said flat face and the surface of said mandrel to be engaged by the end of the bar stock, an extendable and retractable holding means supported from said base and positioned to operate substantially normally to said flat face and extend and engage the spring bar stock when against said stop and hold the flat side of the spring bar stock against said fiat face on said rotary member while said clamp is closed on the spring bar stock to clamp the same against said mandrel and maintain the flat side of the spring bar stock against said flat face, and means to extend and retract said holding means from said spring bar stock before the helical spring coil is formed on said mandrel.

11. The helical spring winding machine of claim 10 characterized in that said clamp is positioned to engage the spring bar stock between the location of said stop and said holding means.

12. The helical spring winding machine of claim 10 characterized in that said holding means applies its force to the spring bar stock forcing its flat side against said fiat face in a direction normal to said flat face and at right angles to the application of the clamping forces by said clamp.

13. The helical spring winding machine of claim 10 characterized by a control means to interlock the operation of said holding means to hold the spring bar stock against said flat face before said clamp end is operated and to retract said holding means while the clamping forces of said clamp subsist and before the rotation of said mandrel.

References Cited in the file of this patent UNITED STATES PATENTS 209,254 Godley Oct. 22, 1878 379,393 Harvey Mar. 13, 1888 2,018,209 Gogan Oct. 22, 1935 2,054,196 Gogan Sept. 15, 1936 2,359,900 Endsley Oct. 10, 1944 2,390,937 Holland Dec. 11, 1945 2,650,638 Johnson et a1. Sept. 1, 1958 2,868,268 Lewis et al. Jan. 13, 1959 2,896,689 Arms July 28, 1959 3,000,427 Gogan Sept. 19, 1961

Claims

10. A MACHINE FOR WINDING A COIL SPRING FROM BAR STOCK HAVING A FLATTENED SIDE ADJACENT ITS END CONSISTING OF A BASE SUPPORTING A ROTARY MEMBER HAVING A CENTRAL OPENING AND A FLAT FACE ADJACENT SAID OPENING, A ROTARY MANDREL RECIPROCABLY MOUNTED ON SAID BASE TO BE EXTENDED INTO SAID CENTRAL OPENING AND RETRACTABLE THEREFROM, MEANS TO ROTATE SAID ROTARY MEMBER AND SAID ROTARY MANDREL, A CLAMP SUPPORTED TO ROTATE WITH SAID ROTARY MEMBER AND EXTENDED AND OPERABLE TRANSVERSELY OF SAID FLAT FACE AND RADIALLY OF SAID MANDREL, A STOP ON SAID ROTARY MEMBER ADJACENT SAID FLAT FACE AND THE SURFACE OF SAID MANDREL TO BE ENGAGED BY THE END OF THE BAR STOCK, AN EXTENDABLE AND RETRACTABLE HOLDING MEANS SUPPORTED FROM SAID BASE AND POSITIONED TO OPERATE SUBSTANTIALLY NORMALLY TO SAID FLAT FACE AND EXTEND AND ENGAGE THE SPRING BAR STOCK WHEN AGAINST SAID STOP AND HOLD THE FLAT SIDE OF THE SPRING BAR STOCK AGAINST SAID FLAT FACE ON SAID ROTARY MEMBER WHILE SAID CLAMP IS CLOSED ON THE SPRING BAR STOCK TO CLAMP THE SAME AGAINST SAID MANDREL AND MAINTAIN THE FLAT SIDE OF THE SPRING BAR STOCK AGAINST SAID FLAT FACE, AND MEANS TO EXTEND AND RETRACT SAID HOLDING MEANS FROM SAID SPRING BAR STOCK BEFORE THE HELICAL SPRING COIL IS FORMED ON SAID MANDREL.