US2040333A - Maneuvering control for reversible engines - Google Patents

Description

May 12, 1936. v E. RATHBUN MANEUVERING CONTROL FOR REVERSIBLE ENGINES Filed June 25, 1954 Patented May 12, 1936 MANEUVERJNG CONTROL FOR REVERSIBLE ENGINES Edward Rathbun, Toledo, Ohio Application June 25, 1934, Serial No. 732,218

6 Claims.

This invention relates to a maneuvering control for reversible engines and is more specifically directed to an automatic device to bring a compressed air, or other starter into reversing operation at the earliest possible moment so as to avoid delay and save manual actuation of the control valves.

Whenever an internal combustion marine engine is stopping, one of the pistons comes up on its compression stroke, and. is unable to pass top dead center because of lack of inertia. The engine then rocks back to relieve the pressure on this piston. Hence, there is always a rocking motion when the engine is brought to rest, regardless of the direction in which it has previously been turning. Obviously, the period when this momentary reversal takes placeis the exact moment when the associated starting devicecan first be brought into play to start the engine in the reverse direction.

The present invention has for its primary object the provision of means to utilize the rocking motion of an engine to initiate actuation of a starting device. 1

A further object of the invention is to provide a device of this character which is positive in its operation, inexpensive .to manufacture, and which is easily adapted .to existing starting systems. a

Other objects and advantages of the present invention will become apparent as the description proceeds, reference being had to the accompanying drawing, in ,which Figure 1 is a partially diagrammatic sectional View of a starting system embodying the present invention. Fig. 2 is a fragmentary section of the device with its parts in. another position shown in Fig. 1. Fig. 3 is a section on line 33v of Fig. 2, and Fig. 4 is a section on the line 44 of Fig. 1.

Referring to the drawing, the device is shown as adapted to control a compressed air starter, fragmentarily disclosed at l, which includes a high pressure air line 2, and valves 3, actuated in any suitable manner. I This device forms no part of the present invention, being merely used in connection therewith, and it need not, therefore, be more specifically shown or described. In prior installations the control for the admission of air to a starter has been manual, or at the most, partially automatic.

A by-pass from the high pressure air line is designated by ID and has a pressure reducing valve interposed therein so that the line Ill carries air under comparatively low pressure.

The low pressure of the line I0 is caused to actu-. ate a main air valve 2 in the main line in a manner hereinafter described. Obviously, this valve may be of any suitable type, such as that disclosed in Fig. 1. As there shown, the valve controls the fiow of air to the starter side of the high pressure air line 2. The valve is urged away from its seat to open position by a spring l3 surrounding the valve stem. A suitable diaphragm 4 of flexible material is clamped between the upper and lower sections of the valve housing and is adapted to be raised againstthe tension of the spring I3 by air pressure exerted on its under surface. It will be seen that so long as the diaphragm I4 is raised, the flow of air to the line 2 will be cut off, since the main air valve is seated. As soon as the pressure on the diaphragm is released, the spring l3 will force it to the collapsed position shown in Fig- 1 and at the same time. open the valve to permit air flow to the line 2.

A. centrifugal governor, which may be the engine control governor or any other, is designated generally by 20, and is moved by. the engine through a shaft 2|. The governor includes a pair of weight members 22, 23, each of which is fixed to a bellecrank lever 26 pinned at 24 to an axially movable yoke member 25 and pivotally connected by one end or arm of the lever 26to a member 21 fixed to the main driving. shaft 2|. Reaction springs 28 are provided and are attached at one end to the links26 and at the other to the yoke, the latter being split to allow space for the insertion of the springs. The yoke 25 comprises a sleeve 25 which is slidable axially on the driving shaft 2| and similar bifurcated arms extending from diametrically opposed points. The weight and bell-crank assembly is carried within the bifurcation of the arms. This governor and yoke form no part of the present invention, but serves as a convenient source of the motion desired to operate the parts hereinafter described.

A driven shaft 29 is carried by the yoke, so as to be movable therewith and. is coaxial with the shaft 2|. Adjacent its lower end, which is received in a housing 30, this shaft has a plate 3| keyed or otherwise suitably fixed thereto. The key used to retain this member is received in along key-way in the shaft and extends downwardly to retain a bushing. 33 and a lower plate 33 which are further held on the shaft and retained against lowering movement by suitable nuts 34. A cup-shaped block member 32 is carried above the lower plate 33 and is free to turn on the shaft about the bushing 33. The block is made to frictionally follow the rotation of the shaft to the desired degree by means of a friction plate 35 pressed by springs 36 against the top plate 3|. These springs are received in pockets 3'! in the block member.

As shown in Figs. 3 and 4, the block 32 is formed with angularly spaced arms 40 and H extending from the periphery. Disposedwithin the housing 30 in the path of rotation of the projecting arms 40 and 41 is a stop member 42 having a stop pin 43 and shoulders 44 and 45 formed;

thereon. M," I.

Interposed in the reduced pressure'line. loeris 7 a spring pressed control valve 50 adapted to engage a valve seatj5l formed in a valve housing 521 The valve 50 has an elongated stem. 5 3 which. is..re.-.-

- duced for a distance adjacent the head of the valve as at 54, so as to permit the flow offair past itinto anou let p pe l -wh h. has com c tion'with' the mairrvalve l2 in the high pressure airline 2.1 'The majorportionof the valve stem' 53 has a sliding fit with the bore in which it moves and extendsdown into the housing 29 to a point radially inward of the stop pin, as, may be seen iniFigsI 2 and 3., A, relief port 55 is formed in the 'valvejhousing 52 sofas to relieve thepressure'in line; HlP assoon as the valve 5ll is,closed. ,The

. relief port, is covered-by. the valve stemwhen:

everthe-valve, is moved to'open position. It will be seen, from. the. above that when. the. valve 50 is open, 'airQfr-oml'the low pressure line lnewill flow aroundthe reduced-portion of the-valve stem into line-lll -and operate to closethe main airvalve 1,2.inthe'high pressure line to the starting device. .As soon .as the valve5ll isrclosed, however,.as by thepressure oispringLGO, the flow of air .iscut off, therelief port is open and the line HIE ,allowedl -.to.: assume atmosphericnpressure.

This reduction in pressure in lineJll and conse quently. on .the diaphragmml 4 .ofthemain air valveflZ allows this latter valve to open and air tofiow into the starting device. W 7

w In operation whenlthe engineis running, the

governor weights 22 and 23 move out by centrifu'gal force and, pivotingabout theconnection with the sliding membersilfraise-the yoke 25. The driven shaft 29 being-fixed to the yoke also rotates "and raises, carrying the block 32 upwardly; The block partakes of the rotational; movement of the shaft only by reason of the clutch disc 35 being urged againstthe plate 3| by springs 36, andturns only until one of the extending arms 40 .or 4| engages the stop pin 43. Obviously, which armcontacts the pindepends on the direction of rotation of the shaft 2 9 When the engine is running inforward direction, the block occupies the positionshown in Fig; 3. Raising the block 32 causes it'to move to a position so that the lower end of the valve stem .53 contacts the --up per surface; of the block, so that upon farther raising of'the shaft and block, the valve 50 isopened. Asipointed out above; the opening of this-valve cuts ,off the starting device by exertand hence'closprojecting arm which has been held against the stop pin 43 can move down only'until it rests on the shoulder 45. In this position, shown in Fig. 2, the valve 50 is still open and the starter cut off. As soon as the engine dies completely, it rocks back due to one of the pistons being unable to overcome the compression stroke in its cylinder.

This reversal of the rotation of the engine obviously causes a reversal of rotation of the driven shaft 29, which movement is' followed by the block. Thus, the arm 40 is moved off of the shoulder which has previously been supporting it and Tthei block drops down, allowing the spring 60 to seat theoontroi valve 50. The pressure on the ther, the form of theg'overnor disclosed is not to be deemed a limitation of the invention, since any device which will afford the desired motion of the parts may be used. N V 7 Obviously, various modifications and changes in the form and disposition of the parts may be made without departing from thefinvention as defined the appended claimsQ Havi g' thus descr'bed my invention, what I claim as new, and desire to secure by: United States Letters Patent, is: 7 H h 1. A control for an internalcombustion engine, comprisinga driven shaft, a speed, responsive devicedriven with said shaft, a starter controlling l e m mb n a s he v e conne o between said deviceand said membermoving the member and valve to; non-starting position, anj abutment upon which said member rests in nonstarting position, and frictional connections between said member and shaft moving the member off of. said abutment when the rotation offthe, shaft is reversed. 4 .2. A control of. the class described including a drive shaft, a driven shaft, speed responsive means connecting said shafts and operable to impart predetermined movements to the l driven shaft relative to the drive shaft, a normally closed air line control valve, means frictionally driven by. said driven shaftand operable by'predetermined speed responsive movements of the driven shaft to move the valve to open position, and stopmeans coacting with said frictionally driven means to stop the rotation of the latter in either direction at a predetermined point and retain it in valve opening position until the direction of rotation of the driven shaft is reversed.

' 3. A control of the class described including rotatable drive and driven shafts, speed responsive means interposed between said shafts and operable toimpart predeterminedaxial movement to the driven shaft relative to the drive shaft, a block. frictionally carried by the driven shaft, stop means coacting with said block to limit the rotation thereof in either direction, said stop means having provision for holding the block in a predetermined position of its axial movement with the driven shaft when at either limit of its rotary movement and to release the block from such position when its direction of movement is reversed, and an air line having a normally closed control valve which is engaged by and moved to open position when said block has predetermined speed responsive. movements. impartedethereto.

4. A control of the class described including a drive shaft rotatable in either direction, a driven shaft rotatably driven by said drive shaft and capable of axial movements, and speed responsive means for imparting axial movements to the driven shaft when the drive shaft is rotated, a member having frictional connection with the driven shaft and movable axially therewith, an air line control valve opened by predetermined movements of said member, and stop means coacting with said member to limit its rotary move-'- ment in either direction and to retain it in valve opening position when at either limit of its permissible rotary movement and until its rotary movement is reversed.

5. In combination, means forming a fluid pressure control line, a drive member rotatable in either direction, a driven member having connection with and rotatable by said drive member and capable of axial movement, speed responsive means actuated by the drive member for imparting axial movements to the driven member, an element axially movable with said driven member and frictionally rotated thereby, a valve actuated by axial movements of said element to open or close said control line, and means including a shoulder adapted to cooperate with said element to limit the rotary movement thereof in either direction with said driven member and, when such member is at either limit of its movement and at a predetermined point in its axial movement to support said element by means of the shoulder at said predetermined axial position so as to hold the valve open, and resilient means closing the valve upon the reversal of rotation of said driven member and its resultant displacement off the shoulder.

6. In combination, a fluid pressure line control valve, a drive member rotatable in either direction, a driven member having connection with and driven by said drive member and capable of axial movements,speedresponsive means actuated by the drive member for imparting axial movements to the driven member, means responsive to both axial and rotary movements of said driven member and, when axially moved in one direction, operable to open said valve, means including a shoulder cooperating with said last means to retain it in valve opening position, and resilient means closing the valve upon the reversal of rotation of said driven member and its resultant displacement oil .the shoulder.

EDWARD RATHBU'N.

Images