US 2380218 A
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July 10, 1945. A. CLAUD-MANTLE 2,380,218
PEDAL ROD MOUNTING OR THE LIKE Filed April 27, 1943 Patented July 10, 1945 UNITED STATES PATENT OFFICE PEDAL ROD MOUNTING OR THE LIKE Arthur Gland-Mantle, Trumbull, Conn., assignor to The Bassick Company, Bridgeport, Conn, a corporation of Connecticut Application April 27, 1943, Serial No. 484,743
2 Claims. (01. 74--'512 This invention relates to pedal rod mountings and like structures in which a plunger or rod is guided longitudinally in a casing or housing, there being a spring embracing the-rod within the I casing, which spring acts on the rod to hold'it normally in a predetermined longitudinal position, the spring being compressed when the pedal associated with the rod is depressed and serving upon release of the pedal to restore the latter to the initial position. Assemblies of this general character are used for example in connection with starter pedals of automobile engines, and also in other applications.
I-Ieretofore it has-been the practice to use an ordinary helical compression spring pressing at one end against the casing or housing and at the opposite end against the rod, this spring being received with a certain amount of clearance within a bore provided in the housing. The clearance around the spring at the periphery thereof allows a certain increase in the diameter of the spring coil when the latter is compressed. Struc tures of this kind are, however, open to a number of practical objections. ,One of these is that" grit frequently becomes lodged in spaces between the turns of thespringso that the spring cannot be compressed properly and the rod cannot be given the necessary movement for the operation of the mechanism. Anotherobjection is that the support of the rod is such as to induce objectionable noise under the effects of vibration. Another objection is that for perfect operation very close tolerances are required and that, if. the parts are not made and assembled in-a very careful manner, the operation is likely to be noticeably faulty and, in any case, the assembly is likely to require frequent attention orrepair.
One of the objects of the present invention is to overcome the above-mentioned drawbacks.
Another object is to. provide amounting of this character, in which the rod is supported in a manner to. overcome objectionable noise and rattling. I
Another purpose of the invention is to overcome sticking of the rod or plunger and more especially to provide a mounting which is selfcleaning so that any grit, dirt, or other accumulation which finds its way into the spaces between the spring 'turns, will be moved out of those spaces. To these and other ends, the invention consists in the novel features and combinations of parts to be hereinafter describedand finally pointed out in the claims.
In the accompanying drawing:
Fig. 1 is a side elevation, partly broken away and partly in vertical section, showing the invention as applied to a pedal rod mounting for an engine starter;
Fig. 2 is a longitudinal sectional view on a larger scale, of the lower end portion of the device shown in Fig. 1;
Fig. 3 is a transverse section through the lower end portion of the housing, taken on line 3--3 of Fi 2, on a still larger scale; and
Fig. 4 is a fragmentary view of the spring alone looking from a position substantially corresponding to line 3-3 of Fig. 2.
In the form shown in the drawing, there is indicated at I0 a fragment of a partition such as employed between the engine space of an automobileand the forward portion of the automobile body. Supported within and extending through this partition is a downwardly and forwardly inclined housing or casing H, within which is arranged a push rod l2 of round cross section having a pedal l3 carried by its upper end. The casing I I may be constructed of sheet metal to provide a tubular formation, but in any event there is a bore M of cylindrical shape in which the rod 12 is received for a" portion of its length,jand the rod is surrounded by compression spring l5 of spring wire having the function of holding the rod normally in the position of Fig. 1. In the particular case illustrated, the lower end of the rod, which is extended out of the spring housing, carries a button l6 for the actuation of a. starter or like mechanism, but this feature is not of importance here. In this particular instance, the rod is extended through a flange I! at the lower end of the housing, formed by bending thematerial of the tube in an inward direction. In this particular case also the lower end of the spring l5 reacts against the flange I1 and the upper extremity of the spring reacts against the body of the pedal l3. Considerable variation may, however, be made in these respects. v
Instead of employing a standard spring, I employ a spring constructed on difierent principles, and this spring has a novel relation to the other parts of the assembly. In particular, the housing has a novel relation to the new spring, because of the fact that, at difierent points of the circumference of the spring, the latter element has engagement with the housing at all times for the purpose of supporting the rod from the housing in a manner to reduce noise and rattling. In the preferred form, the spring is divided along its length into relatively short portions, each of which has 3-point bearing against the surrounding housing, but if desired each sectional portion may have within its length four or more points or places in different circumferential positions bearing against the housing, a principal aim being to support the spring and the rod engaged thereby against the housing so as to have effective centering and sup-port of the rod Within the housing throughout a sufficient portion of the housing length.
In the preferred form shown in the drawing, the spring wire, commencing at one end of the coil as formed, is provided, say at a point 120 along the first turn, with a portion adapted to make supporting contact with the housing, and then, at a point 120 farther along, similar bearing portion is provided, and then at a point 120 farther along, a third similar bearing portion is provided. This provides a section of the spring in which at three points in the length, bearing portions are provided which are spaced circumferentially at equal distances. A number of such sections or portions are provided in the coil, depending upon the length of the latter. These different bearing portions are provided by curving the wire turns irregularly with respect to the axisof the coil as a whole and there are thus created turns which in .this particular case are staggered at 120 along the length of the spring. The spring turns are so related to the embraced cylindrical rod and to the external hollow cylinder that at each 120 of circumference, the external support is engaged, and, at each 120 of circumference, the rod is engaged, whereby there is very effective resilient support of the rod from the housing when the spring is under relatively light compression, as in the condition shown in Fig. 1. The turns are well spaced apart so as to permit considerable compression before the adjacent turns make contact with each other. Owing to the offsetting bf the turns from each other in the manner described, grit, dirt, and the like, entering the housing, can readily work its way through and around the turns to the lower end portion of the housing, and in this location an opening I8 is provided through which the dirt falls out or is werk'ed out as the mechanism is operated.
It will be noted that in the embodiment shown the rod is fully supported from the housing by the spring substantially throughout the length of the housing. This obviates the-need of a guide hole in the lower end of the housing for gjuidingthe rod, and the rod can have ample clearance in the end portion of the housing,
which is a factor in preventin noise and in overcoming sticking of the rod.
It will be noted from Fig. 4. that the outer bearing point or portion of the coil which is nearest the observer is indicated at l9, that the next nearest outer. bearing point is 240 from the first point in a clockwise direction and is indicated at 20, and that the next succeeding one is indicated at 2!. Circumferentially of the spring,v the inner bearing points are between circumferentially adjacent external bearing points In Fig. 4, the inner bearing point next following point IS in a clockwise direction is an arcuate bearing portion indicated at 2|, the next following is indicated at l9, and the next following at 20'. In the particular case shown, the amount of offset of the turns is approxiinately half the diameter of the wire, but this is merely by way of example.
In constructing the spring, the preferred practi'ce is to use an open coiler which coils up the all) wire in a manner to provide the lateral offsets which act in the manner previously described. The Wire is fed forwardly by and between grooved rollers and passes from these rollers against the inner concave face of a shoe capable of a certain amount of movement in the direction of feed of the wire. The advancing end of the wire comes into contact with the shoe and is given abend or set, and 180 of a turn or coil is produced. Then, while the wire continues to advance from the feed rolls, the shoe is given a short retracting movement, followed by a movement back to the initial position, and by thus interrupting the action of the shoe temporarily, the wire portion next formed by the shoe is caused to be offset angularly to a slight degree from the portion first coiled. Then when the total amount of coil formed reaches 240, this operation (the shifting of the shoe) is repeated and so on. During the movement of the shoe a short length of wire of somewhat irregularc'urvatu're is produced but the variation is so slight as tobe hardly perceptible. The locations of two of these places are indicated in Fig. 4- at 22 and 23', respectively.
It will be understood, of course, that in the operation of the device, the length of stroke of the rod which is necessary forthe desired operation can take place without any undue crowding of the spring turns located within the housing. As the spring has contact with the housing at a number of points which are well-spaced from each other, a considerable increase in the compression of the spring could take place without overcrowding the available space within the bore. As the spring is compressed, the outer spaced b'earingportions continue, of course, to bear against the housing and those portions which engage the rod continue to engage it. It will be understood, of course, that as compared 0 to the standard spring there is no increase in the external diameter of the spring upon compre'ssion, this being prevented by the surrounding housing. The support of the rod from the housing entirely or practically entirely from the interposed spring, arranged in the manner described, gives the rod a flexible support which effectively prevents noise and rattles.
It is desirable to square off the end turns of the coil so that the coil is better adapted to make contact with the cooperating members, and this is done in the example shown.
It will be understood that the self-cleaning feature of the mounting is of great importance because of the fact that the sticking of the rod cannot occur as a result of the lodgment of grit between the turns of the spring. The sifting out of the grit is obviously facilitated by the fact that relatively long turn portions are out of contact with the housing and out of contact with the rod. The device is therefore much more reliable inoperation than those heretofore used.
In devices such as used previously, employing a standard spring, the clearance between the spring and the inner surface of the housing has been 'very small, and hence a slight bend or deformation of the rod would interfere with the operation. In accordance with my invention, there is considerably more clearance provided between the major portion of the spring body and the housing and this permits a considerable deviation of the rod from straightness without any harmful effect, the coil spring being free to deform to compensate for the deformation of the rod. The same or similar conditions apply where a1 mounted Wholly on one end of the rod, an actuator on the other end of the rod, a housing having a bore With an open end disposed around the rod and facing toward the pedal at a distance from the pedal, the other end of the housing being located adjacent the actuator, said rod intended for rectilinear movement in and through the housing but being maintained substantially free of guiding engagement with said housing by means of a coiled spring surrounding the rod and located partly Within the housing and acting against the rod to urge the pedal away from the housing, said spring having offset portions Whereby in all operative positions of the rod the latter is' supported from the housing, the turns of the spring being well spaced apart in the normal position but being brought close together on depression of the pedal.
2. A pedal rod device for a starter or the like having a tubular housing, a push rod intended for rectilinear movement in and through the housing but being maintained substantially free of guiding engagement with said housing by means of an open coiled spring surrounding the rod and located partly within the housing, said spring acting on the rod to maintain it normally in a predetermined longitudinal position and having turns which support the rod laterally from the housing and constitute the sole means positioning the rod laterally with respect to the housmg. ARTHUR CLAUD-MANTLE.