US3253622A

US3253622A - Spring looping machine

Info

Publication number: US3253622A
Application number: US362030A
Authority: US
Inventors: Aloysius H Hammersmith
Original assignee: Friden Inc
Current assignee: Friden Inc
Priority date: 1964-04-23
Filing date: 1964-04-23
Publication date: 1966-05-31
Anticipated expiration: 1983-05-31

Description

y 31, 1966 A. H. HAMMERSMITH 3,253,622

SPRING LOOPING MACHINE Filed April 23, 1964 films/us H. HAMMEPSM/TH INVENTOR.

AT TOM/EV United States Patent 3,253,622 SPRING LOOPlNG MACHINE Aloysius H. Hammer-smith, San Francisco, Calif., assignor to Friden, Inc, a corporation of Delaware Filed Apr. 23, 1964, Ser. No. 362,030 6 Claims. (Cl. 140-103) This invention relates to an automatic spring looping machine, and particularly to a mechanism for trimming the connecting loops formed on the ends of precoiled springs.

The primary object of the present invention is to provide a trimming, or cutolf, device for trimming the terminal, or connecting, loops formed in the ends of precoiled'springs, whereby the loop is cut off or trimmed short of the body of the spring instead of penetrating into the coil of the spring.

Another object of the present invention is to provide automatic trimming means for use in the spring looping machines shown and described in the patents of Ashley- Ving, No. 3,040,784, issued June 26, 1962, or the patent of Lehtonen, No. 3,156,269, issued Nov. 10, 1964. Such looping machines normally form a loop of substantially the full terminal coil of the spring which, when completely formed, normally penetrates into the interior of the spring coil, as seen in FIG. 6 of the drawing. Such springs are more difiicult to aflix to their respective spring seats than if the coil were terminated just short of the end of the spring, as shown in FIG. 7. The present invention relates to a device comprising a modified form of anvil and the forming plate of the pick assembly, whereby the spring loop is trimmed to avoid penetration of the coil of the spring.

These and other objects of the present invention will be apparent from the description and claims which follow, and they, inturn, will be more readily understood by reference to the accompanying drawing in which:

FIG. 1 is a plan view showing a forming turret, and the co-operating forming tool assembly, both of which are substantially the same as the same elements in the patent of Ashley-Wing, No. 3,040,784, or the patent of Lehtonen, No. 3,156,269, previously mentioned, as modified by my present invention.

FIG. 2 is a side view of the mechanism shown in FIG. 1 with the forming tool in its operative, or spring looping, position.

FIG. 3 is a partial and cross-sectional view of the mechanism shown in FIG. 2, but with the bending plate and probe, or pick, shown in FIG. 2, removed.

FIG. 4 is a detail showing the construction of the forming anvil, and the bending and cutting plates which are mounted on the forming tool assembly, with the pick and supporting arm removed for the sake of clarification.

FIG. 5 is a plan view of the mechanism shown in FIG. 3, showing the tip of the probe in cross-section.

FIG. 6 is an elevation of the end of a spring formed in the conventional automatic spring loopers, such as those shown by Ashley-Wing and Lehtonen, in which the end of the terminal loop penetrates into the space within the coil of the spring.

FIG. 7 is a similar elevation of the end of a spring showing the loop formed by the device of my present invention, and indicating the cutting plate in phantom lines.

The spring looping machines to which the present invention is preferably applied, are adequately described in the patents of Ashley-Wing and Lehtonen, above-mentioned. As a matter of fact, FIG. 2 of the present application corresponds to FIGS. 7 and 11 in the Ashley- Wing patent, No. 3,040,784, and to FIG. 3 of the Lehtonen Patent No. 3,156,269. Obviously, only one turret and forming tool is shown in this application, whereas both operating turrets and their forming tools are shown 7 3,253,622 Patented May 31, 1966 in the patents mentioned. It will be understood, of course, that the present invention could be applied to either or both of the forming turrets of both of the said patents. It is, therefore, believed unnecessary to describe the complete machine, for reference can be made to either of the mentioned patents for all detailed construction other than those specifically mentioned herein.

The forming turret 64 (FIGS. 1 and 2) is pivotally mounted on a supporting plate 52, as described in those patents. A single precoiled spring 67 is delivered from a supply conduit 51 to a tube, or conduit, 66 mounted in the turret by some suitable means, such as clamp 63. During its passage through the tube 66, a spring 67 is rapidly rotated, or spun, by means of vibration in the Ashley-Wing machine, or by means of an air jet in the Lehtonen machinein the embodiment shown in those patents and in the present application, the spring being given a clockwise rotation as viewed from the rear or right side in FIGS. 1 and 2.

An anvil member 69 is rigidly mounted on the forming turret 64 by any suitable means, such as screws 70. This anvil is formed with a central recess 71 (see FIG. 4), which is aligned with the axis of the tube 66. This construction forms a pair of forming

shoulders

72 and 73, which are spaced apart, but both of which lie opposed to a major portion of the respective semicircular portion of the tube 66, as shown particularly in FIGS. 1 and 5. The two shoulders are spaced from the periphery of the turret 64 and the end of the bore of the tube 66 by a secondary pair of spacing shoulders 74 and 75 (FIGS. 1 and 5).

In the Ashley-Wing and Lehtonen spring looping machines, the spacing shoulder 75 (FIGS. l, 3 and 5) has a width of slightly greater than the wire diameter from which the spring is formed, whereby one complete turn of the spring will extend beyond the bore of the tube 66. The shoulder 74 is approximately half that width, so that the spinning spring 67 will have a shoulder formed on the inner side of the shoulder 72 against Which the spring abuts. This construction, as shown and described in the patents above-mentioned, enables the spring to extend beyond the bore of the tube 66 one full turn and the cut end of the spring 67 to abut againstan inner face on anvil forming shoulder 72, thus stopping the spring in the proper position for looping.

Co-operating with the turret 64 is a forming tool 186 (FIGS. 1 and 2). This tool comprises an arm 187 which is rigidly mounted on a rotatable shaft 189 (FIG. 2). The shaft is journalled in the supporting plate 52 and a suitable bearing bracket 191 afiixed thereto by any suit able means, such as screws 192. Enclosed within a slot formed in the free end of arm 187 and aligned with the axis of the bore of tube 66 is a forming probe, or pick, 193, which is securedtherein by any suitable means, such as screws 194- (FIG. 2). The lower, or outer, end of each probe forms a loop forming nose, best shown in FIG. 2, the outer edge of which is convex and the inner edge is concave, as described in the patents above-mentioned. The arm 187, adjacent the lower end of pick 193, is angled, or cut away, to form anvil faces 195 (FIGS. 2 and 3) which co-operate with the top of

anvils

72 and 73 to form a perpendicular loop in the end coil of the spring 67. Associated with the probe is a single forming plate which, in the patents mentioned, is mounted on the outer face of the nose and extends laterally over and slightly beyond the adjacent sides of the arm 187.

In the machine of the abovementioned patents the spring 67 is spun as it passes down the bore of the tube 66, so that the cut end abuts against the inner surface of the shoulder 72. .At this point in a machine cycle the forming tool 186 is rocked, whereupon the nose of probe 193 enters between the first and second coils of the spring and forces the. end coil away from the balance of the spring. Immediately thereafter, the forming plate (198 in the patents mentioned) passes behind this first coil to hold it against the face of the anvil, and particularly the

shoulders

72 and 73 thereof. Further rocking of the arm 187 causes the lower anvil faces 195 thereof to engage the end coil and bend it over the top of the

anvil shoulders

72 and 73, as shown in FIG. 2.

In the present invention the single forming plate (198 of the patents mentioned) is replaced by two members:

A single bending plate 199, which is mounted on the end of arm 187, and so mounted that it passes the shoulder 72 by a distance sufficient to permit the terminal coil of a spring 67 to lie between it and the face of the shoulder 72; and a cutting bar 200, which is set into the arm so that it engages the inner face of the shoulder 73 as the forming tool moves to its operating position. The bending, or holding, plate 199 is rounded slightly at its lower end to avoid deforming the spring (as shown in FIG. 2),

while the cutting plate 200 is formed with a shearing edge (as shown in FIG. 3).

Likewise in the instant invention, the anvil 69 is modified to co-operate with the two plates. The shoulder 72 is rounded (as shown at 205 in FIG. 4), while the shoulder 73 is formed with a sharp shearing edge 206 (as shown in FIGS. 3, 4 and which is adapted to co-ope'rate with the cutting plate 200 to form a pair of shearing jaws. The holding plate 19? and the rounded anvil 72 are located on the side of the probe away from the terminal end of the spring wire, i.e., on the left-hand side of the probe 193 for a right-hand spring when looking from behind the spring (from the right in FIG. 1); and the cutting plate 200 and the sharply edged shoulder 73 are placed on the outer side of the probe 193 adjacent to the terminal end of the spring loop.

It is seen in FIG. 6 that the terminal end of the spring formed on the machines of the patents above-mentioned, is apt to penetrate the space within the coil of the spring. This makes it rather difiicult for an operator to apply the loop over some of its seats, especially if the seat is an aperture in some other part. In contrast to this, a spring loop formed on the machine of the present invention is terminated a short distance from the balance of the spring, as shown in FIG. 7, which forms a loop which is readily attached to its seat.

It is obvious that the amount of loop retained, or the exact position at which the cutting edge 200 will trim the terminal loop, is a matter of choice and can be adjusted by a mechanic by changing its position on the arm 187 and adjusting the cutting anvil 73 accordingly. Obviously, the farther the cutting plate 200 is from the axis of the shaft 189, the longer will be the loop, and the more the plate 200 is inset into the arm 187, the shorter will be the terminal loop.

I claim:

1. In an automatic spring looping machine having:

(1) a forming anvil,

(2) means for positioning a spring against said anvil,

(3) and a forming tool operative to form a terminal loop in a spring held against the anvil, the combination which comprises:

(4) a rounded edge formed on one side of the anvil,

(5) a shearing edge formed on the other side of the anvil,

(6) a nonshearing forming plate mounted on the forr ing tool and co-operating with the rounded edge of the anvil, and

(7) a shearing plate likewise mounted on the forming tool and co-operating with the shearing edge of the anvil.

2. In an automatic spring looping machine having:

(1) a bifurcated forming anvil,

(2) means for positioning a spring against the face of said anvil,

(3) and a forming tool operative to form a terminal loop in the spring held against the face of said anvil,

the combination which comprises:

(4) a rounded edge formed on one bifurcation of said anvil,

(5) a rounded forming plate mounted on the forming tool and upon operation of said forming tool cooperating with the rounded edge of the anvil to hold the terminal coil against the face of said anvil,

(6) a shearing edge formed on the other bifurcation of said anvil, and

(7) a shearing plate likewise mounted on the forming tool and upon operation of said forming tool engaging the shearing edge of the anvil.

3. In an automatic spring looping machine having:

(1) a bifurcated forming anvil,

(2) means for positioning a spring against the face of said anvil,

(3) and a forming tool operative to form a terminal loop in a spring held against a face of said anvil, said forming tool including a probe adapted to penetrate the bifurcation of said anvil and to pry a predetermined number of coils of a spring held against the anvil from the balance of the spring,

the combination which comp-rises:

(4) a rounded shoulder formed on one bifurcation of said anvil,

(5) a shearing edge formed on the other bifurcation of said anvil,

(6) a forming plate mounted on the forming tool adjacent the probe on t'he side of said anvil with the rounded shoulder and spaced away from the face of said anvil upon operation of said forming tool by a distance equivalent to the diameter of the wire of a spring, and

(7) a shearing plate mounted on the forming tool adjacent the probe on the other side of the probe and spaced to engage the shearing edge of the anvil upon operation of said forming tool.

4. In an automatic spring looping machine having:

( 1) a tube for delivering a coiled spring,

. (2) means for rotating a spring during its passage through said tube,

(3) a forming anvil Which, when the tube and anvil are in operative position, has a transverse shoulder substantially across the diameter of the spring in said tube and a slot substantially perpendicular to said shoulder, the shoulder on one side of said slot being closer to the end of the tube than the other,

(4) a forming tool having a probe adapted to penetrate said slot to separate the terminal coil away from the balance of the spring,

(5) and means co-operating with said anvil to bend said separated coil perpendicularly and thereby form a terminal loop in the spring held against the anvil,

the combination which comprises:

(6) a rounded edge formed on the side of the anvil closestto the tube,

(7) a lshearing edge formed on the other side of the anvl (8) a forming plate mounted on the forming tool adjacent the probe on the side of the forming tool cooperating with the rounded edge of the anvil and spaced away from'the face of the anvil upon operation of the forming tool by a distance equivalent to the diameter of the wire of a spring, and

(9) a shearing plate mounted on the forming tool adjacent the probe on the side of the forming tool co operating with the shearing edge of the anvil and spaced to engage the face of said anvil upon opera- 7 to the end of said tube.

6. In an automatic spring looping machine having:

(1) a tube for delivering a coiled spring,

(2) means for rotating a spring during its passage through said tube,

(3) a forming anvil having a transverse shoulder adapted to engage the end of the terminal coil of said spring,

(4) a forming tool having a probe adapted to separate the terminal coil away from the balance of the spring,

(5) and means co-operating with said anvil to bend said separated coil perpendicularly and thereby form a terminal loop in the spring held by the anvil,

means for forming the terminal loop with the end thereof spaced away from the other coils of the spring which comprises the combination of:

(6) a rounded edge formed on the edge of the anvil spaced away from the face of the anvil upon operation of the forming tool by a distance equivalent to the diameter of the Wire of a spring,

(9) a shearing plate mounted on the forming tool adjacent the probe on the side of the forming tool cooperating with the shearing edge of the anvil and spaced to engage the face of said anvil upon operation of said forming tool, and

(10) means for adjusting the position of the shearing plate and the anvil with respect to the end of the tube and thereby adjusting the point on the terminal loop at Which it is sheared.

References Cited by the Examiner UNITED STATES PATENTS 2,365,876 12/1944 Hicks 140-103 2,951,512 9/1960 Wynkoop 140-103 3,156,269 11/1964 Lehtonen 140-103 CHARLES W. LANHAM, Primary Examiner.

L. A. LARSON, Assistant Examiner.

Claims

1. IN AN AUTOMATIC SPRING LOOPING MACHINE HAVING: (1) A FORMING ANVIL, (2) MEANS FOR POSITIONING A SPRING AGAINST SAID ANVIL, (3) AND A FORMING TOOL OPERATIVE TO FORM A TERMINAL LOOP IN SPRING HELD AGAINT THE ANVIL, THE COMBINATION WHICH COMPRISES: (4) A ROUNDED EDGE FORMED ON ONE SIDE OF THE ANVIL, (5) A SHEARING EDGE FORMED ON THE OTHER SIDE OF THE ANVIL, (6) A NONSHEARING FORMING PLATE MOUNTED ON THE FORMING TOOL AND CO-OPERATING WITH THE ROUNDED EDGE OF THE ANVIL, AND (7) A SHEARING PLATE LIKEWISE MOUNTED ON THE FORMING TOOL AND CO-OPERATING WITH THE SHEARING EDGE OF THE ANVIL.