US3362110A

US3362110A - Coil spring grinder

Info

Publication number: US3362110A
Application number: US401166A
Authority: US
Inventors: Geissmann Marco; Straub Immanuel
Original assignee: Storen und Maschinenfabrik Emil Schenker AG
Current assignee: Storen und Maschinenfabrik Emil Schenker AG
Priority date: 1963-10-04
Filing date: 1964-10-02
Publication date: 1968-01-09
Anticipated expiration: 1985-01-09
Also published as: CH429492A; DE1967563U; GB1038397A

Description

Jan. 9, 1968 M. GEISSMANN ETAL 3,362,110

COIL SPRING GRINDER I Filed Oct. 2, 1964 2 Sheets-Sheet 2 31 Fig. 2

29 'NVENTORS MARCO GEISSMANN Immanuel. 5T RAU B p'rromveys United States Patent 3,362,110 COIL SPRING GRINDER Marco Geissmann, Kilchberg, Zurich, and Immanuel Straub, Wangs, Saint Gall, Switzerland, assignors to Storenund Maschinenfabrik Emil Schenker A.-G., Schonenwerd, Switzerland Filed Oct. 2, 1964, Ser. No. 401,166

Claims priority, application Switzerland, Oct. 4, 1963,

1 Claim. (Cl. 51--124) This invention relates to a machine for surface grinding the end faces of workpieces, particularly the ends of compression springs.

In order to permit uniform loading of compression springs it is necessary that their end faces are situated each in a plane normal to the longitudinal axis of the spring. To this end the contact faces of compression springs such as are used for example in vehicles must necessarily be face ground. To achieve this working process a spring which is normally held between clamping means and guided at right angles with respect to the working face of the grinding wheel, is pressed against the said wheel by means of a uniformly advancing spindle. Such uniform advance or feed has the disadvantage, at least at the beginning of the operation where the cross section of the work-piece is small, to be too slow, while at the end where the cross section to be worked is large, the feed is too rapid. Thus, there is always a risk that the end of the workpiece will become incandescent, and therefore will lose its required shape. Furthermore the grinding capacity of the grinding wheel is gradually decreasing while on the other hand the feed rate remains constant. This will unavoidably result in an overloading and destruction of the grinding wheel.

A further object of the invention is the provision of an improved machine for surface grinding the ends of workpieces of the type referred to above. According to the invention this grinding machine comprises a frame and a rotatable shaft supported therein, a grinding wheel fixed on said rotatable shaft, driving means for said shaft, a swinging carrier means for the workpieces and means for applying the workpieces against the said grinding wheel with a substantially constant pressure.

Further objects and advantages will be more apparent from the following description of the accompanying drawings in which:

FIG. 1 is an elevational View of a grinding machine in accordance with the invention;

FIG. 2 is a side view of the machine shown in FIG. 1.

A grinding machine of known type comprises a housing 1 in which a shaft 2 is rotatably supported. A swinging arm 3, provided at its free lower end with a worktable 4, is pivotally mounted on shaft 2 for swinging in front of face 5a of a grinding wheel 5. A pair of clamping jaws 6, 7 are fixed on the worktable 4 on opposite sides of the longitudinal axis of arm 3. A second pair of movable clamping jaws 8, 9 are provided below the said first pair 6, 7 and exactly opposite thereof. The jaws 8, 9 are secured on

rods

10, 11 which in turn are slidably guided in correspondingly shaped vertical bores 16a, 11a in arm 3 whereby upon actuation of two

spindles

14, 15 provided each with a

hand wheel

12 and 13, respectively, in either one or the other direction, the jaws 8, 9 are displaced to or from the corresponding fixed jaws 6, 7. The sole purpose of these coarse adjusting means is to guide and clamp the work-pieces. In the embodiment shown, the left hand clamping device is holding a pair of springs 16 of small diameter, while the other clamping device is centering and holding a pair of springs 17 of relatively great diameter. The working or contact surfaces of the jaws 6 to 9 are V-shaped thus permitting to securely hold springs having diameters varying in a very wide range. The clamping devices are provided with

inserts

18, 19 and 20, 21, the removal thereof permitting the fixing of springs of still greater diameter.

The free ends of

spindles

14, 15, i.e. the ends opposite the said :

hand wheels

12, 13, are connected each by an

intermediate piece

22 and 23, respectively, to one of the

piston rods

24, 25 of double-acting pneumatic or

hydraulic jacks

26, 27. The proper clamping of the

springs

16, 17 is effected by the withdrawal of

pistons

24, 25 into the cylinders of

jacks

26, 27.

The lower portion of the grinding wheel 5 penetrates into a container 28 partially filled with a cooling liquid 29, such as for example water. During rotation in the direction indicated by arrow 30, a certain amount of water is entrained by wheel 5 thus cooling the different working sites as will be described in more detail below.

Channels

31, 32 and baffles are provided for directing the cooling liquid to the desired places. Thus bafile 33 at the upper end of channel 31 is directing the cooling liquid to the right hand working place. The other working place is cooled with liquid coming from outlet 34 at the end of channel 32. The shaft 2 extends through housing 1 and has a swinging lever 35 fixed thereon. This lever 35 is driven by the reciprocating piston rod 36 of a pneumatically actuated jack 37. Suitable valve means of known type (not represented in the drawing) feed pressure air alternatively into the cylinder spaces on either side of piston 36a of jack 37, thereby causing a swinging movement of determined length of the arm 3.

A guiding rod 38 (FIG. 2) rigidly connected to the shaft 2 by arms 39, 4d and thus effecting the same swinging movement is provided and passes through a bore in the upper portion of arm 3 for pushing the latter against the face 5a of the grinding wheel 5. A double-acting pneumatic jack 41 is mounted on the arm 3 between the guiding rod 38 and the shaft 2. A piston 42 is rigidly connected to the arm 40 and may be extended and retracted to move the swinging arm 3, which is slidingly held on shaft 2 and guiding rod 38, to or from the grinding wheel 5. Adjustable stop'per means 44, 45 are provided for limiting the feed course of arm 3. These stoppers 44, 45, when in their end positions, are actuating a contact 46 causing the swinging arm 3 to stop its movement.

The grinding machine operates as follows: The

springs

16, 17 are fixed in the clamping devices by actuation of the

hand wheels

12, 13 followed by the actuation of the

cylinders

26, 27 Thereafter the swinging arm 3 is reciprocated in front of the grinding wheel 5 by the said pneumatically actuated jack 37. This swinging movement of arm 3 moves the

springs

16, 17 over the whole working face of wheel 5 thereby causing a continuous abrasion of the wheel. The pneumatically controlled feed by the pneumatic jack 41 causes the springs to be applied against the front face 5a of wheel 5 With a substantially constant pressure. The different working areas are simultaneously subjected to an intensive cooling by the cooling liquid which is entrained by the rotating wheel 5 and, owing to the occurring centrifugal forces, fed through the

channels

31, 32 and therefrom directed to the working areas. When the swinging arm 3 reaches its end position, the pressure is still maintained during a short period in order to permit the ends of the springs to be subjected to a precise surface grinding.

It will of course be understood that various changes in details of construction and arrangement of parts may be made by those skilled in the art without departing from the spirit of the invention as set forth in the appended claim.

We claim:

1. A grinding machine particularly for grinding coil springs, comprising a rotatable grinding Wheel, a workpiece supporting swing arm, means pivotally mounting said swing arm for pivotal movement about an axis substantially perpendicular to said grinding wheel for swinging said swing arm backwardly and forwardly adjacent one side face of said grinding wheel, workpiece clamping jaws Carried on said swing arm arranged for holding a workpiece substantially normal to said grinding wheel, adjusting means connected to said jaws for opening said jaws for clamping them around a workpiece, such as a spring, and for holding the workpiece substantially normal to said grinding wheel, fluid pressure operated means connected to said swing arm for pivoting said swing arm to cause movement of said jaws with the workpiece therein from side to side over said grinding wheel, fluid pressure holding means connected to said swing arm and urging said swing arm in a direction toward said grinding wheel to hold the workpiece in said jaws against said grinding wheel with a constant pressure, a shaft member pivotally supporting said swing arm disposed adjacent and substantially perpendicular to a side face of said grinding wheel, said swing arm being slidable along said shaft,

and a crank frame pivotally supported on said shaft and having an upper spindle member extending through said swing arm and being parallel to said shaft, said fluid pressure holding means including a fluid cylinder member carried by said swing arm having a piston engageable with said frame and being movable to displace said swing arm away from said frame.

References Cited UNITED STATES PATENTS 665,380 1/1901 Barnes 51267 1,436,860 11/1922 Church 26932 2,021,602 11/1935 Jackson 51124 2,095,438 10/1937 Hall 51124 2,104,345 1/1938 Holhut 51124 2,127,877 8/1938 Maglott 51233 X FOREIGN PATENTS 504,388 7/1920 France.

HAROLD D. WHITEHEAD, Primary Examiner.

Claims

1. A GRINDING MACHINE PARTICULARLY FOR GRINDING COIL SPRINGS, COMPRISING A ROTATABLE GRINDING WHEEL, A WORKPIECE SUPPORTING SWING ARM, MEANS PIVOTALLY MOUNTING SAID SWING ARM FOR PIVOTAL MOVEMENT ABOUT AN AXIS SUBSTANTIALLY PERPENDICULAR TO SAID GRINDING WHEEL FOR SWINGING SAID SWING ARM BACKWARDLY AND FORWARDLY ADJACENT ONE SIDE FACE OF SAID GRINDING WHEEL, WORKPIECE CLAMPING JAWS CARRIED ON SAID SWING ARM ARRANGED FOR HOLDING A WORKPIECE SUBSTANTIALLY NORMAL TO SAID GRINDING WHEEL, ADJUSTING MEANS CONNECTED TO SAID JAWS FOR OPENING SAID JAWS FOR CLAMPING THEM AROUND A WORKPIECE, SUCH AS A SPRING, AND FOR HOLDING THE WORKPIECE SUBSTANTIALLY NORMAL TO SAID GRINDING WHEEL, FLUID PRESSURE OPERATED MEANS CONNECTED TO SAID SWING ARM FOR PIVOTING SAID SWING ARM TO CAUSE MOVEMENT OF SAID JAWS WITH THE WORKPIECE THEREIN FROM SIDE TO SIDE OVER SAID GRINDING WHEEL, FLUID PRESSURE HOLDING MEANS CONNECTED TO SAID SWING ARM AND URGING SAID SWING ARM IN A DIRECTION TOWARD SAID GRINDING WHEEL TO HOLD THE WORKPIECE IN SAID JAWS AGAINST SAID GRINDING WHEEL WITH A CONSTANT PRESSURE, A SHAFT MEMBER PIVOTALLY SUPPORTING SAID SWING ARM DISPOSED ADJACENT AND SUBSTANTIALLY PERPENDICULAR TO A SIDE FACE OF SAID GRINDING WHEEL, SAID SWING ARM BEING SLIDABLE ALONG SAID SHAFT, AND A CRANK FRAME PIVOTALLY SUPPORTED ON SAID SHAFT AND HAVING AN UPPER SPINDLE MEMBER EXTENDING THROUGH SAID SWING ARM AND BEING PARALLEL TO SAID SHAFT, SAID FLUID PRESSURE HOLDING MEANS INCLUDING A FLUID CYLINDER MEMBER CARRIED BY SAID SWING ARM HAVING A PISTON ENGAGEABLE WITH SAID FRAME AND BEING MOVABLE TO DISPLACE SAID SWING ARM AWAY FROM SAID FRAME.