US2002196A - Engine brake - Google Patents

Description

Ma l, 1935. B. UCKO 2,002,196

ENGINE BRAKE Filed March 9, 1931 INVENTOR flernard Mk0,

a if: cmMQ m 111,5 ATTORNEYS Patented May 21, 1935 v ma 1 was;

. to International Motor Company, New York, '1 N. 1.,dcorporationo! Delaware appumidn Marcus; 1981, serial so. and

' sfoi misucilizaeoi I The'present invention relates toiengine bralre's and embodies, more specifically, an improved form of brake, wherein the engine is converted i into a true two cycle aircompressor, thus effec- 'l tively braking the same.

More particularly, the invention embodies an improved braking mechanism for internal combustion engines which is readily applicable to standard makes and types of engines without 'modifying the construction thereof or altering,

arm shaft turning mechanismiin such fashion as to cause the exhaust valve opening mechanism to function when the rocker arm valve actuating mechanism is rendered inoperative, thus causing air tobe drawn into the' cylinders upon thedown strokes of the respective pistons and compressed upon the upstrokesp An object of the invention is to provide'an engine brake design which does not add to the length oftheengine. I i

A further object of theinvention is toprovide an engine brake design "which is simple in construction andoperationand theparts of which may be added to any engine structure without modifying the engine design or materially altering the auxiliary elements thereof. I A further object or the invention is to-provide a device of the above character, wherein the conventional valve mechanism is utilized as the engine brake mechanism when it is desired'that the engine operate as abrake. p j i i i A further object of the invention is to provide a rigid andquiet drive, this object being attained by the utilizing of mechanism which does not require the shifting of the cam shaft, 9. further obiect oi the invention being toprovide a'structure wherein the brake elements are independent of the engine and thus do not impair thenormal operation of the engine upon failure of such elements.' Further objects, not specifically enumerated above, will be apparentas the invention is described in greaterdetaii in connection with the accompanying drawing, wherein the single figure of the drawing isa view in section taken through acylinder head andvalve actuating mechanism of aistandard form of engine,the engine brake" structure of the present invention being shown as pads 290i therespective rods 25.

brakes 'I'heoperation of the deviceis as folhaustpassage H and an exhaust port l2. E x- B haust valve I3 is mounted upon a valve stem it i I which'is carried in a sleeve l5 mounted in, the head and a collar 16 seats a valve spring- H to maintain the valve normallyclosed, U

Rocker arm shaft 18 is mounted upon eccenl9 trics l9. and is thus shifted eccentrically of the axis of the eccentricsby means of a shifting lever 20. Rocker armsiil are carried by, the shaft I 8 and are iormed with heads 22 which engage the top ofvalve stems UL; i Upon the other end oi therockermarms, adjust able tappets 23 are mounted, these tappets being engaged bycupsid upon push rods 25; Lost motion springs are provided between the rocker arms and the respective push rods. 25, and inlet 20 and exhaust earns 21 on cam shaft 28 engagethe The foregoing mechanism is of standard form and typical of internal combustion engines. In combination with valve actuating mechanisms of 25 this character, a brake actuating mechanism is provided which includes a conduit 30 communicating with the main oil line, not shown. Upon a power shaft which may be the cam shaft or drivenby the cam shaft, a brake cam 3| is pro- 30 vided; this cam being a double lobe cam for each cylinder. The cam actuates. a primary brake ac- .tuatine pump 33 which communicates with a conduit 34. It will be understood, of course, that wcationbetween theconduit 34 and: the conduit 3 30, while a reiease valve 41 and conduit "permits the oil pumped by the pump to be returned to the engine when the brake mechanism is notinuse.

A suitable link 43 causes the release valve I to cooperated simultaneously with therocker am shaft shifting lever to prevent lubricant ;frcm being returned to the engine-lubricating system when it is desired to operate the engine actuate the inlet and exhaust valves in the usual manner. When it is no longer desired to actuate the engine, the rocker arm shaft is shifted by meansof the lever 20 to lift the rocker arms and raise the tops 23 from the sockets 24, thus renderingthepush rods ineffective to actuate the valve mechanism. Both the inlet and exhaust valves of the engine therefore remain closed and the braking mechanism functions to lift the exhaust valves upon the down strokes'of the pistons to conduit. 34 and forces the piston 36 downwardly to depress shaft 38, head 22, and valve'rod l4.

This takes place on each exhaust valve as the respective pistons move downwardly and the engineisthus converted into an air compressor.

It will be seen that theforegoing mechanism does not add to the length of the engine and utilizes the conventional valve mechanism of the engine to cause the engine to function as an air compressor and thus effect braking. Noshifting cam shaft is required therefore providing a rigid and noiseless drive and the parts are relatively inexpensive and simple to construct and to maintain. The engine design is not modified nor is the auxiliary equipment thereof materially changed and the braking mechanism does not constitute a part of the'engine which functions during nor mal engine operation. In view of this last condition, failure of the brake system does not impair'the normal operation of the engine.

Where a multi-cylinder engine is formed of a plurality of independent blocks each carrying one or more cylinders, it willbe seen thatthe valve mechanism of the cylinders of the respective blocks may be utilizedin groups or simultaneously, to effect the progressive graduation of the braking effect.

It is of considerable advantage to provide a bleed valve 44 at the highest point in the fluid system, the valve being operated by stem 45 and cam 46 on the rocker arm shaft l8. When the rocker arm shaft is shifted to such position that the engine functions as a brake, the bleed valve 44 is closed under the action of spring 41 and the fluid system is thus rendered tight. Upon the return of the rocker arm shaft to its normal position the cam 46 opens the valve MS, as will be readily apparent from an inspection of the drawing.-

' While the invention has been described with specific reference to the accompanying drawing, it is not to be limited, save as deflned in the appended claims.

I claim as my invention: l

1. In combination with an engine having an exhaust valve and a rocker arm for actuating the valve, means to vary the position of the rocker arm to render it ineffective to actuate the valve, a pump, a motor actuated by the pump, and means to cause the motor to open the exhaust valve. j

I 2. In combination with an engine having an exhaust valve, a rocker arm for actuating the valve, and a cam shaft for actuating the arm, means to vary the position of the axis 01. the arm to render it ineffective to actuate the valve, a pump driven by the cam shaft, a motor actus m lows. Under normal running conditions, the rocker arm shaft is inthe down position as shownin-solid lines in the drawing and the push rods ated by the pump, and means actuated by the motor to open the valve.

3. In combination with an engine having an exhaust valve, a piston, a rocker arm for actuating the valve, and a cam shaft for actuating the varm, means to vary the position of the axis of exhaust valve, a rocker arm for actuating the valve, and sham shaft for actuating the arm,

means to vary the position of the axis of the arm to render it ineffective to actuate the valve, a pumpdriven by the cam shaft, a motor, a conduit connecting the pump and motor, a valve for relieving pressure in the conduit, a conduit communicating with a source of fluid, and a check valve in the last named conduit to prevent the fiowof fluid from the pump and. motor to the source. p

5. In combination with an engine having an exhaust valve, a rocker arm for actuating the valve, and a cam shaft for actuating the arm, means to vary the position of the axis of the arm to render itineffective to actuatethe valve, a pump driven by the cam shaft, a motor, a conduit connecting the pump and motor, a valve for relieving pressure in the conduit, a conduit com-r municating with a source of fluid, a check valve in the last named conduit toprevent the flow of fluid from the pump and motor to the source, and means to actuate the relief valve from the rocker arm actuating means.

6. In combination with an engine having an exhaust valve, a rocker arm for actuating the valve, and a cam shaft for actuating the arm, means to vary the position of the axis of the arm to render it ineffective to actuate the valve, a pump driven by the cam shaft, a motor actuated by the pump having a piston rod adapted to engage the rocker arm, means to'mount the motor above the valve stem, a conduit connecting the pump and motor, a valve for relieving pressure in the conduit, a conduit communicating with a source of fluid, and a check valve in the last named conduit to prevent the flow of fluid from the pump and motor to the source.

7. In combination with an engine having an exhaust valve, a rocker arm for actuating the valve, and a cam shaft for actuating the arm, means to vary the position of the axis of the arm to render it ineffective to actuate the valve, a pump driven by the cam shaft, a motor actuated by the pump having a piston rod adapted to engage the rocker arm, means to mount the motor above the valve stem, a conduit connecting the pump and motor, a valve for relieving pressure in the conduit, a conduit communicating with a source of fluid, a check valve in the last named conduit to prevent the flow of fluid from the pump and motor to the source, and means to actuate the relief valve from the rocker arm actuating means.

8. A valve mechanism for internal combustion engines permitting the engine to act as a braking means, comprising the usual valve-operating'assembly including a push rod element and a connecting lever element between the push rod and said elements of each assembly for rendering the said exhaust-valve operating assembly inoperative and means for opening each of the said exhaust valves during the down stroke of the engine piston. V

9. A valve mechanism for internal combustion engines permitting the engine to act as a braking means, comprising the usual valve-operating assembly including a push rod and a connecting lever element between the push rod and the exlever element of each assembly for displacing said lever element to render the said exhaustvalve operating assembly inoperative and means for positively opening the said exhaust valve 'haust valve stem for positively opening each exhaust valve, means operating on the connecting

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