US3690189A

US3690189A - Engine starter

Info

Publication number: US3690189A
Application number: US74695A
Authority: US
Inventors: Paul D Webb
Original assignee: FRASER WEBB CORP
Current assignee: FRASER WEBB CORP
Priority date: 1970-09-23
Filing date: 1970-09-23
Publication date: 1972-09-12
Anticipated expiration: 1989-09-12

Abstract

A device for applying a large torque to start a large engine. A member pivoting about the axis of a drive gear has an idler gear pivotally mounted on it which is in mesh with the drive gear so that when the member is rotated about the axis of the pinion gear, the idler gear is brought into contact with the fly wheel gear on the engine so that it can be turned by the drive gear to start the engine.

Description

United States Patent Webb [ Sept. 12, 1972 [54] ENGINE STARTER v [72] Inventor: Paul D. Webb, Tioga, Pa. l6946 [73] Assignee: Fraser-Webb Corporation [22] Filed: Sept. 23, 1970 [21] Appl.No.: 74,695 g 52] Us; 01. ..74/8, 123/179 F 51 1111.01. ..F0ln 7/08 58 Field of Search ..74/& 123/179 F; 92/119 [56] References Cited UNITED STATES PATENTS 1,262,666 4/1918 Heinze ..74/8 x 2,905,001 9/ 1959 Courtney et a1 ..74/8

6/ 1969 Meyer ..74/8 7/1912 Desmond ..92/l19 Primary Examiner-Milton Kaufman Attorney-John E. Wilson [57] ABSTRACT A device for applying a large torque to start a large engine. A member pivoting about the axis of a drive gear has an idler gear pivotally mounted on it which is in mesh with the drive gear so that when the member is rotated about the axis of the pinion gear, the idler gear is brought into contact with the fly wheel gear on the engine so that it can be turned by the drive gear to start the engine.

2 Claims, 2 Drawing Figures OFF 52 PATENTEDSEP 12 I972 ATTORNEY ENGINE STARTER BACKGROUND OF THE INVENTION which would be used to drive such a pump isby necessity'large and powerful and therefore one which would require the application of a large torque to crank it.

Conventionally, several Bendix-type starters which engage with the fly wheel ring gear are used to crank the engine.- I The engine, which is often approximately l,0,000 I-l.P. .demands much of the starters and consequently, they often fail mechanically.

SUMMARY OF THE INVENTION It is an object of the presentinvention to overcome drawbacks found in the prior art such as those discussed above. Accordingly, an idler gear in mesh with adrive gear moves so thatwhile continuously in mesh with the drive gear, it comes into mesh with an engine gear so that it can transmit torque to the engine gear and start the engine.

' BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic view of a mechanism made in accordance with the present invention; and

FIG. 2 is aschematic view of the pneumatic circuit within the scope of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1 a portion of a large engine is shown with an engine gearl2-which may be'a ring gear integral with a fly wheel 14.

A starter mechanism 16 has a drive gear 18 fixed on a shaft 20 which may be turned by means of gas under pressure acting on a positive displacement helical lobe screw type expander or other means for exerting sufficient torque. Mounted for pivotal movement about the shaft 20 is a member 22 which-is pivotally connected at one end 214 to an end of a piston rod 26 of a power cylinder 28. The power cylinder 28, which may be of the double acting pneumatic type is pivoted at the cylinder end 30 to the frame 32 of the starter apparatus. Rotatably mounted at the other end of the member 22 is a shaft 36 upon which is mounted an idler gear 38 whichfis in mesh with the drive gear 18.

The member 22 can be rotated about the shaft 20 by the power cylinder 28. Thus, if the cylinder pressure were to move the piston rod 26 downward, the idler gear would be moved upward, the end of its travel being the position shown in phantom in FIG. 1. Similarly, if the rod 26 were then to be moved upward the idler gear 38 would move downward. When the engine 10 is running, and the engine fly wheel gear 12 is turning, the idler gear 38 is held in the position shown in phantom in FIG. 1. When the present starter is cranking the engine, the idler gear is in the position shown in full line in FIG. 1. In this position, the member 22 engages, at a location adjacent to the shaft 36, a saddle 40 which extends downward and is preferably connected with a foundation under the present starter 16.

The member 22 includes a downwardly extending projection 42 which, when the idler gear is in the full line position, engages a limit valve or limit switch 44 for reasons which will appear presently.

Ithas been pointed out previously that when the engine 10 is running the idler gear 38 is in the phantom line position. When the engine, 10 is not running and it is desired to start it, the power cylinder 28 is actuated to raise the piston rod 26 and rotate the member 22 about the shaft 20. While this taking place, the idler gear 38 is rotating about its own axis in a counterclockwise direction because it is in mesh with the drive gear 18. When the idler gear 38 contacts the ring gear 12 it will rotate about its own axis in a clockwise direction to rotate the drive gear slightly. This action greatly lessens any possibility of the idler gear becoming hung up" on the fly wheel gear. Even if it did, the cylinder 28 will not exert enough force to damage the gear teeth.

When the member 22 contacts the saddle 40 it will no longer rotate and the drive gearis then made to rotate to turn the idler gear 38 and thefly wheel gear 12. The engine gear 12 exerts a large reaction force on the idler gear 38 and consequently the resultant force on the idler gear 38 will be large and in a downward direction. The saddle will transmit this force to the foundation so that the starter mechanism 16 will not be damaged.

When the engine 10 is tired and the fly wheel ring gear 12 begins to turn rapidly the gear 38 will be thrown upwardly so that the member 22 will rotate about the shaft 20 until the idler gear 38 is in its phantom line position. This action occurs because after the engine fires it drives the starter to reverse the direction of the resultantforce on the idler gear. Preferably the cylinder pressure is, at this time reversed to urge the rod 26 downward and thereby aid in the disengagement of the starter 16. Because the idler gear 38 is moved upwardly by the ring gear 12, the teeth on each of these gears always move at the same linear speed until the idler gear disengages. This prevents any damage to the teeth.

In FIG. 2, a hydraulic system 50 which is suitable for incorporation in the present invention, is diagramatically shown. The gas cylinder 28 along with the member 22, engine gear 14, drive gear 18, idler gear 38 and the limit switch 44 which have already been mentioned are all shown.

When it is desired to start the engine 10 a control valve 52, which is preferably a four-way valve, is actuated to the on position as shown in FIG. 2. Gas under pressure will flow from gas source 54 through the fourway valve, pneumatic lines 56 and 58 through a second control valve 60, which may be a spring return valve, the pneumatic lines 62 and 64 and through the pneumatic limit switch 44 to the blow-off 66. The spring return push button 68 is then pushed inwardly to close the valve and thereby prevent the gas from reaching the blow-off 66 so that the gas will flow through the pneumatic line 70 to the gas cylinder 28. Pressurizing the gas cylinder 28 will cause it to rotate the member 22 to bring the idler gear 38 into the position shown in full line in FIG. 1. The projection 42 will therefore engage and actuate the pneumatic limit switch 44 to eliminate blow-off at 66. This occurs in only a short time after the button 68 is depressed. The operator may then allow the button 68 to return to its normal position without relieving pressure at the lines 62 and 70 so that the cylinder 28 will remain pressurized. When the spring return valve is opened by releasing the button 68 gas under pressure will flow through the line 62 and a line 72 to a diaphragm 74 of a starter gas supply valve 76 which controls flow of gas to the starter. When the diaphragm 74 becomes pressurized it actuates a rod 78 which opens the supply valve 76. This allows gas under pressure to energize the starter which rotates the drive gear 18.

When the engine fires the four-way valve 52 is turned to the off position to rotate the valve core ninety degrees so that gas from the cylinder can pass through lines 70 and 56 to be blown off at 80 and for gas under pressure to pass through line 82 to the top of the cylinder and its piston. As already explained, the engine after it. starts, runs the starter and since the member 22 is no longer held in position by the cylinder 28 the member will be thrown upwardly, that is in a clockwise direction by the force of the engine gear 12 and the cylinder which moves the rod 26 downwardly. This, of course, will cause the idler gear 38 to disengage from the ring gear 12 and assume the phantom line position shown in FIG. 1.

It has already been explained that the present invention is useful in engines which are. used to pump gas in gas lines. In such environments, gas under pressure is available and can be used in the pneumatic system 50. Of course, if air or any other suitable fluid were available under sufficient pressure it could be used and function satisfactorily.

The present engine starter has several inherent advantages which have not been discussed thus far. For one, if any of the pneumatic lines were to rupture, the starter could not be engaged. If the rupture occurred after it was engaged it would disengage. It is also to be noted that the starter will not operate until the pneumatic limit switch 44 is closed, that is until after the member 22 is moved fully into position. Further, two valve operations namely actuation of the four-way valve 52 and spring return valve 60 are necessary to engage and operate the present starter. However, to disengage the starter, it is only necessary to actuate either one of those valves. It will be readily apparent how each of these features makes the present starter extremely safe.

The foregoing describes but one embodiment of the present invention. One of ordinary skill in the art will appreciate that the described embodiment may be modified without exceeding the scope of the present invention as defined in the following claims.

I claim:

1. A device for starting an engine having an engine gear comprising a drive gear for transmitting torque and an idler gear, said idler gear being in mesh with said drive gear, a member pivotally mounted for rotation a out the axis of said drive e r, said idler ear bein pivotally connected with sai d member, a powe cylinder connected at one end of said member so that it will rotate said member when said power cylinder is actuated so that the axis of said idler gear rotates about the axis of said drive gear while said idler gear meshes with said drive gear to bring said idler gear into mesh with said engine gear and to a position suitable for transmitting torque from said drive gear to said engine gear, said device further comprising a first control valve, a line for directing fluid under pressure coming from said control valve to said power cylinder, a second control valve, a line for directing fluid pressure from said first control valve to said second control valve, a starter supply valve and a limit valve, said starter supply valve adapted to supply fluid under pressure to rotate said'drive gear, said limit valve adapted to direct fluid to a blow-off when open and being positioned so as to be closed by said member when said idler gear is in said position suitable for transmitting torque from said drive gear to said engine gear, lines for directing fluid pressure from said second control valve to said limit valve and said starter supply valve, whereby when said first control valve is actuated to direct fluid to said power cylinder, fluid will flow through said second control valve and said limit valve to blow-ofl', but when said second control valve is closed, said fluid will flow into an end of said power cylinder to rotate said member and close said limit valve so that said second control valve can be opened to allow fluid to flow to said starter supply valve.

2. The device defined in claim 1 wherein said power cylinder is a double acting cylinder and said first control valve can be activated to supply fluid to the other end of said cylinder to rotate said member into the position where said idler gear is out of contact with said engine gear and to direct fluid from said one cylinder end to blow-off.

Claims

1. A device for starting an engine having an engine gear comprising a drive gear for transmitting torque and an idler gear, said idler gear being in mesh with said drive gear, a member pivotally mounted for rotation about the axis of said drive gear, said idler gear being pivotally connected with said member, a power cylinder connected at one end of said member so that it will rotate said member when said power cylinder is actuated so that the axis of said idler gear rotates about the axis of said drive gear while said idler gear meshes with said drive gear to bring said idler gear into mesh with said engine gear and to a position suitable for transmitting torque from said drive gear to said engine gear, said device further comprising a first control valve, a line for directing fluid under pressure coming from said control valve to said power cylinder, a second control valve, a line for directing fluid pressure from said first control valve to said second control valve, a starter supply valve and a limit valve, said starter supply valve adapted to supply fluid under pressure to rotate said drive gear, said limit valve adapted to direct fluid to a blow-off when open and being positioned so as to be closed by said member when said idler gear is in said position suitable for transmitting torque from said drive gear to said engine gear, lines for directing fluid pressure from said second control valve to said limit valve and said starter supply valve, whereby when said first control valve is actuated to direct fluid to said power cylinder, fluid will flow through said second control valve and said limit valve to blow-off, but when said second control valve is closed, said fluid will flow into an end of said power cylinder to rotate said member and close said limit valve so that said Second control valve can be opened to allow fluid to flow to said starter supply valve.