US1150291A - Valve-timer for internal-combustion engines. - Google Patents

Description

T.'W'. MORGAN.

VALVE TIMER FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. 30, I912.

Patented Aug. 17, 1915.

2 SHEETSSHEET 1.

THOMAS W. MORGAN, OF WATERLOO, IOWA, ASSIGNOR T0 WILBUR W. MARSH, OF

. WATEBLOO, IOWA.

VALVE-TIMER FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Aug. 17, 1915.

' Application filed December 30, 1912. Serial No. 739,193.

To all whom it may concern:

Be it known that I, THoMAs W. MORGAN, a citizen of the United States, and a resident of Waterloo, in the county of Blackhawk and State of Iowa, have invented certain new and useful Improvements in Valve- Timers for Internal-Combustion Engines, of which the following is a full, clear, and exact specification.

My invention relates to internal combustion engines, and has more particular referonce to improvements in valve timers therefor.

The primary object of my invention is to provide an improved valve timer for reversible internal combustion engines.

A. further object of my invention is to provide an improved mechanism of this character which will be simple, durable and reliable in construction, inexpensive to manufacture, and effective and elficient in operation.

Other objects of my invention will appear hereinafter.

My invention consists in the features of novelty exemplified in the construction,

combination and arrangement of parts herein described, and shown in the accompanying drawings which illustrate one embodiment of my invention, and more particularly pointed out in the appended claims.

i In the drawings, Figure 1 is an end elevation of a single cylinder internal combustion engine embodying my invention. Fig. 2 is a view of said engine in elevation at 'right angles to that of Fig. 1. Fig. 3 is an enlarged elevation of the cam and gear mechanism. Fig. 4 is a sectional view on the line 44 of Fig. 3. Fig. 5is a fragmentary section on line 5-5 of Fig. 3. Fig. 6 is a viewof the cams and valve actuating mechanism embodying my invention as a plied to a four-cylinder engine; and Fig. is a lefthand end view of the mechanism shown in Fig. 6.

My invention concerns more particularly to the valve timing and operating mechanism of internal combustion engines, and for the sake of simplicity of illustration, I have shown in-the drawings a single cylinder engine of the type in which only the ex haust valve mechanism is operated by cams driven from the crank shaft. It will be obvious, however, to one skilled in the art, after having obtained an understanding of my invention from the disclosures herein made, that my invention may, without departing from the scope and spirit thereof, be applied to other types of internal coinbustion engines, such for instance, as the type wherein both the exhaust and intake v sages. by which the gas is conveyed to the cylinder and the exhaust conveyed therefrom for the reason that these parts and mechanisms may be of any usual or standard construction well known in the art. Suilice to say that the rod 1 which reciprocates vertically in'the bearing 2 on the head of the cylinder in the usual way is representative of the valve mechanism of internal combustion engines. The rod 1 moves vertically downward in its bearing as is well known to open the exhaust port and allow theescape of exhaust gases and moves upward in its bearing toclose said port. These rods, in engines of the type of which that shown in the drawing is representative, are constantly pressed upward by the spring 3 to hold the exhaust port closed, spring 3 bev ing disposed between the head of the cylinder and a collar 4 on the rod. At the proper time for the port to be opened the walking beam 5 is operated to depress the rod 1 against the action of its spring 3. This walking beam may be of the type used in connection with single cylinder internal combustion engines. It consists of a substantially horizontally disposed lever centrally pivoted upon an upstanding lug 6 cast on the cylinder head, as shown clearly in Figs. 1, 2, 8 and 9. The arm 7 of this walking beam is arranged in position to act upon the upper end of the rod 1 and depress it at the proper time. A screw memher 8 is generally provided for adjusting the apparatus 14 is positioned in such relation to the valve actuating rodll that it may be actuated thereby, an arm 15 being mounted upon the member 11 for this purpose. As is well known these mechanisms are so timed in relation to each other that the spark will occur at proper intervals. The sparking apparatus needs no further explanation.

It is generally well known that internal combustion engines may be run in either direction of rotation, depending upon the direction in which they are initially started. The opening and closing of the valve, however, must bear a definite time relation to the operation of the engine. In other words, the valves open and close at certain points in the cycle of operation of the piston and these points, as is well known, change in accordance with the direction of rotation of the engine. In accordance with my invention I provide valve timing mechanism which times the valves properly relatively to the direction in which it is desired to run the engine without the necessity of having to disassemble and reassemble the parts or mechanism. As a simple way of carrying out my invention, I provide a pinion spur gear 20 on the crank shaft A which gear is arranged to drive a larger spur gear 21 mounted upon a suitable stud shaft 22 projecting from the side-of the crank case A of the engine. The centers of the crank shaft A stud shaft A and the valve actuating member 11 being preferably positioned in vertical alinement. The large gear 21 is free to rotate on the stud shaft. Adjacent one face of the large gear 21 I provide a cam 23. This cam is rotatably mounted upon the hub of the gear 21, as shown in Figs. 4 and 5, so that both cam and gear may be independently rotated. The cam 23 when it rotates, reciprocates the valve actuating member 11. The lower end of the member 11 carries a small anti-friction roller 25 which engages and runs on the surface of the cam 23. During the operation of the engine it will be seen that the cam 23 must occupy such a position relatively to the piston of the engine that the exhaust valve will be operated at the proper time. The relative position of the cam for one direction of rotation of the engine will not, as is readily seen, serve for the other direction of rotationand consequently the cam must be relatively shifted, and for this reason, asbefore intimated, the cam may be rotated relatively to the gear 21. Since, however, the cam after being rota-tively shifted to-itsproper position must be maintained in position I provide a connection be tween the gear 21' and the cam which permits of these conditions. In the structure shown this connection is preferably formed by two small spring pressed pins 30 projecting from the inner face 31 of the cam and adapted to enter small depressions in the adjacent face of the large gear 21. These small pins are preferably hollow (Figs. 3, 4, 5 and 6) for the reception of the small spiral springs-32. The pins are 'mounted to slide in suitable bores or holes in the face of the cam 21. The springs 32 are held in place by the removable screw caps 35 and tend to yieldingly force the member or pins 33 against the face of the gear 21. The ends of these pins are preferably cone-shaped so that when a centain amount of relative rotative force is applied to the cam the small pins will yield and ride out of the depressions in the face of the gear 21. I provide two sets of depressions 36 for the spring pressed pins. The two depressions in each set are placed in the proper relative position corresponding to the directions of rotation of the engine. For instance: in Figs. 1 and 3 the cam is shown in the proper relative position corresponding to the direction of rotation of the crank shaft indicated by the arrow X. (Fig. 1), while the dotted outline (Fig. 1) of the cam shows it in proper position corresponding to the direction of rotation of the crank shaft indicated by the arrow Y. It will thusbe seen that by simply shifting the cam rotatably a slight amount it may be conveniently and properly positioned to actuate the valve member 11 and the valve mechanism in proper timed relation to the other parts of the engine depending upon the direction of rotation of the engine. This cam, if desired, maybe shifted manually before the engine is started, but I prefer that this operation take place automaticallv. For this reason I so proportion the parts that during the initial movement of the crank shaft and larger gear in either direction of rotation the cam will be automatically shifted to the proper position corresponding to that direction of rotation, and

the engine may be run continually in that direction without any further necessity of adjusting the cam or other operating part. This automatic operation may be simply accomplished by arranging the valve actuating member 11 and the other parts of the valve mechanism in such manner that they will offer suflicient resistance to the turning of the cam to shift it from one set of depressions to the other. In order, however,

to prevent further relative rotation of the cam after it has been properly shifted, as above described, I provide a curved slot 38 1n the large gear 21. In thisslot a bolt 39 is adapted to operate. This bolt is, as shown in Fig. 5, inserted through a slot in the gear and screwed into the cam 23. The ends of the slot, co-acting with the bolt, serve as limit stops corresponding to the two positions of the cam, and hence after the cam has been shifted from one of its positions to the other the bolt and slot prevent. further rotation thereof during the continuous operation of the engine. This bolt also is intended to serve as a locking means for locking the cam and gear together in the event that it is'desired to run the engine for any extended length of time in one direction. In other words, after the cam has been shifted either automatically or manually, as the case may be, to the position corresponding to the direction of rotation of the engine, the bolt may be tightened to clamp the cam firmly to the gear, and the engine may then be started and stopped as many times as desired without danger of the adjustment being disturbed.

As before intimated, my invention is equally as applicable to two or four cylinder engines, or engines embodying commercially practicable number of cylinders, and in. order that this may be clearly understood, I have illustrated my invention as applied to a four cylinder engine. I consider it unnecessary to illustrate a complete engine in this connection and for this reason I have, in Figs. (3 and 7, illustrated a portion of the crank shaft and the cam shaft together with the interconnected driving mechanism. In this construction the cam shaft is considerably longer than the cam shaft 22 for the single cylinder engine, so that it may extend in operative relation to the valve actuating members 11 of the severalv cylinders. This shaft carries four cams 23 angularly arranged around the cam; shaft 22 so as to operate the valve rods 11in their proper se-,

qnence. It would be impracticable and inconvenient, although possible, to provide a cam and gear connectlon for each of the .valve actuating members 1'1, and for this reason I provide a common arm or member 45 adjacent the gear 21. This arm is keyed or otherwise securely fastened to the cam shaft 22 but the gear 21 is rotatable thereon. Only one spring pressed pin 32 instead of two as in Fig. 1, is necessary, hence it is only necessary to provide one depression 36 for each of the two relative positions of the arm 45 with respect to the direction of rotation of the parts. The arm 45 has a similar bolt and slot connection 39 and 3 8 respectively, with the'large gear. This construction performs the same functions as previously described in connection with the single cylinder engine. Thus the four cams can be automatically positioned as a group with respect to the direction of rotation instead of an individual mechanism for each of the four cams.

It will thus be seen that my invention provides a very simple and effective means for timing the valve mechanism with respect to the direction of rotation. When the mechanism is arranged to operate automatically, as previously described, the initial movement of the parts in either direction when cranking the engine automatically shifts the cams and times them with respect to the particular direction of rotation of the engine, and no further manipulation or adjustment is required. The engine may then continue to operate in that direction of rotation with its valve mechanism correspondingly timed When it is to be reversed, the act of cranking in the reverse direction automatically shifts the cam accordingly.

What I claim is:

'1. Thecombination with the cam shaft of an internal combustion motor, of a gear wheel mounted thereon and driven from the engine shaft, said gear wheel being provided with an arcuate slot concentric to the cam shaft, a cam journaled on the shaft at one side of said gear wheel, a pin on said cam movable len thwise of said slot, a looking dog for hol ing the cam with its said pin at either end ofthe slot, and a spring for yieldingly maintainingthe said locking dog and cam in holding position.

2. The combination with a cam shaft of an internal combustion motor, of a gear wheel mounted thereon and driven from'the engine shaft, said gear wheel being provided With an arcuate slot concentric to the cam shaft, a cam journaled on the cam shaft in proximity to one side of said gear wheel, a pin mounted on said cam engaging said slot, and a locking dog holding said pin at either end of the slot. I

3. The combination with a cam shaft of an internal combustion motor, of a gear wheel mounted thereon and driven from the engine shaft, said gear wheel being provided with an arcuate slot concentric to the cam shaft, a cam journa-led on the cam shaft proximate to the side of the gear wheel, a pin mounted on said cam for engaging said slot, a locking means for holding said pin at either end of said slot, and a spring for pressing the locking means into engaging position.

4. The combination of a cam shaft, a gear journaled on said shaft and having an arcuate slot, a cam secured to said shaft and positioned adjacent said gear. a pin on said cam extending into said slot, said gear also having a pair of depressions in its face cor responding to the relative position of the pin in said arcuate slot, and spring-pressed elements with the pin at the ends of. the slot and adapted to be engaged by said springpressed dog to hold the said pin in the corresponding end of the slot.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing Witnesses, on this 27th day of December AD. 1912.

THOMAS \V. MORGAN. \Yitnesses:

H. B. PLUMB,

Ms. M. HUBBARD.

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