US2546560A

US2546560A - Controlling cam

Info

Publication number: US2546560A
Application number: US643432A
Authority: US
Inventors: Pedersen Hans Vilhelm Flygel
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-03-18
Filing date: 1946-01-25
Publication date: 1951-03-27
Anticipated expiration: 1968-03-27

Description

March 27, 1951 v PEDERSEN 2,546,560

CONTROLLING CAM Filed Jan. 25, 1946 2 Sheets-Sheet l March 27, 1951 H. v. F. PEDERSEN CONTROLLING CAM 2 Sheets-Sheet 2 Filed Jan. 25, 1946 INVENTOR. H. 1 Pads/-53 Patented Mar. 27, 1951 CONTROLLING CAM Hans Viihelm Flygel Pedersen, Copenhagen,

Denmark Application January 25, 1946, Serial No. 643,432

' In Denmark March 18, 1941 Section 1, Public Law 69%), August 8, 1946 Patent expires March 18, 196i.

Claims.

This invention relates to a composite controlling cam, especially intended for controlling fuel pumps or valves in reversible internal combustion engines, and the invention aims at shaping such a controlling cam so that it may be advantageously employed for both directions of rotation of the engine.

In reversible engines it was formerly the practies for one and the same fuel pump to have two different controllin cams fitted closely beside each other on the cam shaft, one controlling cam being only intended for the working of the engine in one direction, the other only for the working in the other direction. At reversing, the camshaft was shifted longitudinally, whereby at the same time the roller of the fuel pump intended for co-operation with the controlling cam had to be raised from the controlling cam that had till then been in action, in order that the other controlling cam might unhindered pass in under the roller at the shifting of the camshaft. This method was rather complicated, an extra shaft (the manoeuvring shaft) quired, the purpose of which was to raise the roller of the fuel pump from the camshaft during the reversing.

Experiments have been made to simplify the reversing by turning the camshaft a certain number of degrees, dependent on the reversing angle, then coming out with one controlling cam for each fuel pump, which cam has then in return been furnished with two entrance surfaces or cam face parts, i. e. one for ahead Working and one for astern working. As a result of the two cams or cam face parts for ahead and astern respectively being completely dependent on each other, such controlling cams, however, suffer from the great drawback that an adjustment of the controlling cam out of regard to the working in one direction will entail a corresponding adjustment 1 of the cam face part acting for the working in the opposite direction, which will generally give less advantageous conditions for the working in the latter direction if an adjustment is made for obtaining a satisfactory working in the former 1 direction.

It has furthermore been proposed to combine one controlling cam of two or more single cams placed beside one another, one of which being secured to the shaft, the other or others being adjustable by being turned around the axis of the cam. Such a controlling cam is not, however, well. suited for the transmission of large pressures and furthermore suffers from the drawback that the individual cams cannot be substituted by others Without first completely disconnecting the shaft.

Thi invention aims at avoiding the drawbacks attached to the known controlling cams while preserving the advantages of effecting the reversgenerally being re-' ing only by a turning (angular shifting) of the camshaft.

By the invention is employed a controlling cam of the kind consisting of two mutually engaging controlling cam parts which have each its cam face part, which together form an integral or continuous cam profile, the two controllin cam parts being mutually adjustable by turning around the axis of the controlling cam and able to be maintained in a desired mutual position, and the purpose of the invention is fulfilled thereby, that the cam face parts on the two controlling cam parts, with a View to the application of the controlling cam for the control of fuel pumps in reversible internal combustion engines, are constructed or shaped as active cam face parts, active each for its direction of revolution for actuating the pump plunger for efiecting the pressure stroke of the pump, and that the two controlling cam parts besides are constructed or performed in such a way, that individually they can be clamped adjustably and so as to be easily changed (i. e. without dismounting the cam shaft itself or neighbouring controlling cams or other parts mounted on the cam shaft) direct or indirect, on the cam shaft, e. g. on a boss fitted on the latter.

The two controlling cam parts according to the invention are suitably mainly shaped as semicircles and at both ends shaped with mutually corresponding engagement parts known per so which permit a turning in relation to each other of the controlling cam parts which further have oblong holes and a key-shaped axially directed guide intended for engagement with a ringshaped conical recess in a boss on the cam shaft.

According to a further embodiment of the inventicn the two cooperating engagement parts at the ends of the two controlling cam parts are shaped in such a way that both ends of the controlling cam parts engage mutually with engagement parts, the cam face parts of which are co-axial with the cam shaft, it being for instance so performed that a projection or key at each end of the one controlling cam part engages with a groove or key-way on each end of the other controlling cam part.

The two controlling cam parts may suitably be of the same or approximately the same size, each of them extending somewhat over of the circumference, for instance about 200.

With a controlling cam according to the invention an adjustment of each cam face part may be effected independently of the other cam face part, so that in an engine it is possible to regulate e. g. the time of ignition for the normal direction of rotation of the engine in the best possible way according to the conditions under which the en gine is to work without any detrimental effect on the time of ignition when the engine is running 3 in the opposite direction. If it be desired to substitute one controlling cam part by another curvature, or during a necessary repair it is possible to make a direct change of the controlling cam parts in question, i. e. without disconnecting the earn shaft or the boss on it to which the controlling cam parts have been secured.

By the said shaping of the controlling cam according to the invention is also attained the great advantage that an entrance surface is ob-- tained on the controlling cam, which surface has the full cam width and will thus very well be able to take up and transmit the large pressure acting on the entrance surface, in contra-distinction to what is the case in known controlling cams composed of single cams or discs, where the pressure will act more or less partially on the cam roller from the narrow single cam or disc acting at that moment, and at the transition from one disc to another will be shifted from one side of the roller face to the other.

The invention is illustrated on the accompanying drawing by an embodiment of a controlling cam consisting of two parts in accordance with the invention,

Figs 1 showing the two controlling cam parts in side elevation and withdrawn from each other,

2 the two parts in perspective View and engaged with each other,

Fig. 3 a side elevation of the whole controlling cam, and

Fig. 4 a section along the line IVIV in Fig. 3.

I and 2 designate the two controlling cam parts which have mainly the shape of circular ring parts, and which extend each over about 200 and at the ends by milling out have been furnished with

engagement parts

3 and 4 respectively, corresponding to each other, the latter of which is a key fitting in a keyway in the part 3. The outer surfaces of the

engagement parts

3 and 3 are concentric with the bore of the controlling cam, so that an adjustment of the two controlling cam parts cannot entail any alteration in the smooth transition between the cams or

cam face parts

5 and 6 respectively shaped on the two controlling cam parts.

In the embodiment shown the controlling cam consists, besides of the two parts i and 2, of a boss 7 intended for being secured to the cam shaft !5 by means of a key l5 as shown in Figs. 3 and 4. To said boss 7 the two controlling cam parts are clamped by a number of screws is], which are screwed down into tapped holes 8 in the boss 1 and carried through holes 9 situated in the controlling cam parts, the said holes being oblong in the direction of the rotation out of regard to the adjustabilit To ensure the reliability of an adjustment of the controlling cam parts i and 2 in relation to the boss, each of the said parts is provided with a cone ll engaging with a corresponding conical recess l2 in the boss 7. The oblong holes 9 are covered with segments l3, and locking plates 25 are plated outermost over these.

In Fig. 1 a and b designates the points of the

cams

5 and 6 corresponding to the ignition times for ahead and astern respectively, and as it will be seen, it is possible by said construction to adjust separately each of these times within rather wide bounds, which may be necessary, as the angle of advance of the cams may vary a great deal in engines of the same type and the same size, and it is amongst other things dependent on the number of revolutions.

The invention is not bound to the construction shown and described which is, as before mentioned, only an embodiment for illustrating the principle of the invention.

I claim:

1. A controlling cam comprising two mutually engaging parts shaped substantially as semi-circles havin at each end telescoping portions, each of said parts having a cam surface and together forming a continuous cam profile, each of said parts being adjustable about the axis of the cam and a boss fixed to a cam shaft upon which said parts are fixed when in adjusted position.

2. A controlling cam comprising two mutually engaging parts of substantially semi-circular configuration having at each. end telescoping portions, each of said parts. having a cam surface and together forming a continuous cam profile, each of said parts being adjustable about the axis of the cam, a boss keyed to a cam shaft having a groove therein, a projection on each or" said parts engaging said groove and means for looking said projections in said groove.

A controlling cam comprising two mutually engagin parts of substantially serni-circular configuration having at each end telescoping portions, each of said parts having a cam surface and together forming a continuous cam profile, each of said parts being adjustable about the axis of the cam, a boss keyed to a cam shaft having a groove therein, a projection on each of said parts engaging said groove, said parts having oblong holes therein, said boss having threaded holes therein and locking bolts threaded in said threaded holes extendin through said oblong holes for Securing said parts to said boss.

4. A controlling cam comprising two mutually engaging parts shaped substantially as semi-circles having at each end telescoping portions, each of said parts having a cam surface and together forming a continuous cam profile, each of said parts bein adjustable about the axis of the cam and means for fixing said parts to a cam shaft when in adjusted position.

5. A controlling cam comprising two mutually engaging parts shaped substantially semi-circular having at each end telescoping portions, each of said parts having a cam surface and together forming a continuous cam profile, each of said parts being adjustable about the axis of the cam and a boss fixed to a cam shaft upon which said parts when in adjusted position are fixed in such a manner that they are exchangeable each per so from the cam shaft without necessitating dismounting of the boss.

HANS VILI-IELM FLYGEL PEDERSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS