US2473343A - Centrifugal switch device - Google Patents

Description

June 14, 1949.

G. LEVESQUE Du RosTu CENTRIFUGAL SWITCH DEVICE Filed July 20, 1945 Patented June 14, 1949 CENTRIFUGAL SWITCH DEVICE Georges Levesque du Rostu, Paris, France, as-

signor to Societe Anonyme Andre Citroen, Paris,

France Application July 20, 1945, Serial No. 606,226

In France June 27, 1942 Section 1, Public Law 690; August 8, 1946 Patent expires June 27, 1962 3 Claims.

My invention has for its object spark advancin control device for internal combustion engines and is intended to reduce the number of parts and to simplify the operations of assemblage.

Said centrifugal switch device is based upon the centrifugal action of a mass carried by one or several springs secured without an intermediate fulcrum or like member at one end to the driving shaft and at the other end to the camshaft. By the action of the centrifugal force the mass tends to move away from the axis of rotation, thus causing the spring to deform elastically and the angular set of the driving shaft to vary with respect to the camshaft.

Preferably, the spring consists of a steel wire or the like formed at either end thereof with a loop received in a groove provided in each shaft. The mass is fitted on the spring so that it cannot swing thereabout.

According to one peculiarity of the subject matter of the invention the breaker arm together with the pivot and the adjustable contact are carried as a whole by a sheet-metal member received in an annular recess provided in the casing.

The simultaneous adjustment of th initial spring stress and of the lead magnitude is obtained by means of a ring member secured on the driving shaft and formed with abutments which are set with respect to each other at 180 plus the amount of the adjustable lead and which correspond to abutments spaced through 180 provided on the camshaft.

A preferred embodiment of the subject matter of this invention will now be more particularly described, reference being had to the appended drawings wherein:

Fig. 1 is a vertical cross-sectional view.

Fig. 2 is a plan view corresponding to Fig. 1, the upper cap being taken away.

Figs. 3, 4 and 5 show the timing device in front, side and plan view respectively.

Fig. 6 is a detail view of the timing device, while Fig. 7 is a plan View of the upper side of the abutment ring-member of the same.

Fig. 8 is a. similar View of the member coopating with said ring member.

Fig. 9 shows a detail in cross-sectional view through a plane passing through the medial part of the mass.

Fig. 10 illustrates a detail of another form of securing the mass. I

Essentially, the ignition device comprises the 2 driving shaft I and the camshaft 2 which drives the circuitbreaker; the whole is housed in a casing 5 on which the adjusting device 6 is mounted.

The ignition control mechanism (Figs. 3, 4 and 5) comprises a driving shaft l alined with the camshaft 2. The angular set of these shafts with respect to each other is obtained by means of one or several symmetrical springs I. Each spring is secured at one end to shaft l and at the other end to shaft 2.

Preferably, the spring consists of a steel Wire formed at either end thereof with a loop 8 received in a groove 9 in the shaft; a pin 26 fitted in a recess 21 (Fig. 9) or a flat portion 28 (Fig. 10) retains the loop from slipping in the groove and moving about the shaft.

Said spring is curved at the place where the mass 4 is attached, same being made for instance of two halves provided with a groove havin the same radius of curvature R as the spring and assembled by means of rivets l0. As shaft I rotates the mass or masses 4 by the action of the centrifugal force will tend to move away from the axis of rotation which results in an elastic deformation of the spring and a shifting of the driving shaft with respect to the camshaft, and consequently a variation of the angular set.

Breaker arm I I, pivot l2 and adjustable contact 6 are carried as a whole by a sheet-metal member 13 secured by a screw M to the casing 5 (Fig. 2). For that purpose, said casing is formed with an annular recess IS in which the sheetmetal member I3 is fitted; said recess also retains the cardboard insulator l5 of the leading-out ter minal l1. It is to be noted that the breaker arm II is operated by cam II' formed on part 3 (see Figures 1 and 2).

The sheet-metal member I3 is bent at its end 18 to carry the pivot 12 of the circuit-breaker. Tapped at its other end is a hole 20 for the tungsten-contact set screw.

For defining the starting point and the extent of the lead it is only necessary to adjust the tension of spring I.

In the case of an ignition control device with no secondary timing it is possible to modify together the starting point and the extent of the lead. To this end the circuit breaker rigid with camshaft 2 is formed with two abutments 2| corsponding to the abutments 22 on ring-member 23 secured on the driving shaft I. The abutments A on shaft 2 are set at from each other, while the angular spacing of the abutments on shaft I is 180 plus the desired lead magnitude. A sim.

3 pie operation in either direction of washer 25 is sufficient for adjusting the lead.

Ring-member 23 is provided with an adjusting slot 24. In Qrder to retain said, ring from. being carried with as thelooking nut is being tightened, provision is made between said ring-member 23 and the nut of a washer 25 formed with a flat poi tion fitting a corresponding flat portion machined on the threaded end of shaft I.

What I claim as my invention and desire tov secure by Letters Patent is:

1. An automatic spark advancing mechanism for internal combustion engines including at least one mass submitted to centrifugal force, formed by two superposed symmetrical members-showing a groove in the cooperating surfaces thereof, a.

spring to which said mass is directly secured; a. driving shaft, a cam shaft the angular shifting of which with reference to the driving shaft defines the variation in the lead and means for securing the ends. of the. spring respectively csaid wo shafts, the radius of curvature of the springin the" part. to which the mass; is secured match-. ing the radius of curvature of the groove.

2. automatic spark advancing mechanism for internal, combustion engines. including at least one mass; submitted to, centrifugal force, a. yield-. ingi-wire ending with a loop. ateach. end. a-drivin shaft, a cam shaft the angular shifting of which with reference to the, driving shaft defines the variation in the lead, each of said two. shafts beingprovided near their cooperating ends with an annular groove in which the corresponding the variation in the lead, each of said two shaftsbeingprovided near their cooperating ends wit an annular groove in which the corresponding looped end of the wire is inserted, said spring ending: with fiat ends, each shaft including a flat part for engaging the corresponding flat end of the spring and preventing any rotation of the spring round the shaft considered.

GEOBGE EVE QUE- 1 R KEEEBENCE GITED The following references are; of record in. the

I file of this patent:

UNLTED. STATES PATENTS.

Number Name Date,

1,691,757: Dick Nov. 13, 1928 FORE GN PATENT Number Country Date 84,870. Austria. -,g July 25,, 1,921

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