US1259876A

US1259876A - Starting system for internal-combustion engines.

Info

Publication number: US1259876A
Application number: US87765914A
Authority: US
Inventors: Franz Kratz
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1914-12-17
Filing date: 1914-12-17
Publication date: 1918-03-19
Anticipated expiration: 1935-03-19

Description

F. KRATZ.

STARTING SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. I7. I9I4. 1,259,876.

Patented Mar. 19, 1918.

2 SHEETS-SHEET l.

72 IIIIINII i4 vI/ITNIEE-E E5 g z wzaE 2.; 525 /22 fie F. KRATZ.

STARTING SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED DEC. 17. I9I4.

1,259,876. Patented Mar. 19, 1918.

2 SHEETS-SHEET 2.

WITNESS S IBNEIJTUFK UNITED STA 1 ENT FRANZ KRATZ, 0F STUTTGAR'I', GERMANY, ASSIGNOR TO THE FIRM 0F ROBERT BOSCH, 0F STUTTGART, GERMANY.

STARTING SYSTEM FOR INTERNAL-COMBUSTION ENGINES.

Specification of Letters Patent.

Patented Mar. 19, 1918.

Application filed December 17, 1914. Serial No. 877,659.

To all whom it may concern."

Be it known that I, FRANZ KRATZ, a subject of the Emperor of Germany, residing at and whose post-ofiice address is Schlosstrasse 59 Stuttgart, Germany, have invented certain new and useful Improvements in Starting Systems for Internal- Combustion Engines; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In order that the starting system may be automatically released when the internal combustion engine with which it is associated starts to operate under its own power, an over-running clutch is sometimes provided for transmitting the power from the starting motor or hand-crank to the engine. HoWeVer,-if pawls form the connecting element of the clutch, they remain in contact with their ratchet wheel after the engine is under way, and therefore they wear away rapidly and produce considerable noise. Likewise, if rollers or balls form the connecting element, they roll in their cages after the engine is under way, and since they are at that time rotated at very high speed, they heat and wear excessively. For these reasons, an independently rotatable part has been placed between the driving and drivenmembers of the clutch, but in this case the connecting element remains in contact with both members until the starting system comes to a standstill, wear and noise resulting during the period of retardation of the starting system.

The object of the present invention is to provide a starting system, either with or without a starting motor, wherein disengaging mechanism is provided for holding the connecting element of the over-running clutch out of contact with the driving or driven member. In the preferred embodt ment 9f the invention, wherein a starting motor of the, electric, air or other type is used, thestarting system is so coordinated with the disengaging mechanism that when the starting motor is connected to its source of power supply, the connecting element of the clutch engages both the driving and the driven members for rotation as a unit to transmit power from the motor to the engine; and when the source of power is disconnected from the motor, the disengaging Furthermore, where pawls are used as the connecting element of the clutch, the operator is given notice to disconnect the source of power supply as soon as the engine gets under way, if he should have failed to do so in time.

In the accompanying drawings illustrating the preferred form and several modifications within my invention,

Figures 1, 3 and 5 are diagrammatic views of the different embodiments wherein an electric starting motor is used to drive the intermediate driving shaft of an automobile or motor boat as anexample; and

Figs. 2 and t are partly diagrammatic cross sections of the over-running clutches shown in Figs. 1 and 3.

In the drawings, the crank shaft 1 of the engine is connected by a

friction clutch

2, 3 to the intermediate driving shaft 4., which carries the gear 60 in the speed change box in the well known way, and an electric motor 5 carries a gear 6 operating the driving member '4' of the overrunning clutch. The motor is connected to the battery 1:2 by an

electric circuit

24, 25, 26 containing the switch 13.

In the modification shown in Figs. 1 and 2, the over-running clutch has a driven memher 8, fast on the intermediate shaft i, and a driving member 7 resting on the rollers 9 in the cages 10, the springs 11 tending to force the rollers into the contracted parts of the tapered passages of the cages. .The electromagnet 15 is energized from the battery 12 upon closing the switch 14, and the armature shaft 16, acting against the tension spring 23, closes the switch 13 and rocks the forked lever 17 upon its pivot 18. The driven member 8 carries pivoted disengaging pawls, each having a tail-piece 21 adapted to press a roller 9 into the deep part of the cage out of contact with the driving member 7, thereby compressing the spring ii. and completely disengaging the driving and driven members. Each of the pawls has a projecting portion 22 cooperative with the conical surface of the collar 20. The

forked lever 17 engages a slot of the collar, the arrangement being such that when the switch 13 is closed, the projecting portions 22 of the disengaging pawls ride on the low portion 19 of the conical surface, and permit the rollers 9 to operatively connect the driving and driven members, but when the switch is opened, the disengaging pawls ride on the high portion 18 of the collar and positively force the rollers 9 out of operative engagement.

Upon closing the switch 14 to start the engine, the switch 13 is closed by the 'electromagnet, whereupon the battery supplies starting current to the motor. The driving member 7 is then rotated in the direction of the arrow in Fig. 2 and the rollers 9 transmit the power from the starting motor 5 to the intermediate driving shaft 4. At the proper time, the intermediate driving shaft is connected to the crank-shaft of the engine by means of the

clutch

2, 3. As soon as the engine starts under its own power, the operator opens switch 14, whereupon switch 13 is opened by the spring 23 and the collar 20 is shifted toward the right in Fig. 1, so that the projecting portions 22 of the disengaging pawls ride upon the high part of the conical surface of the collar and force the rollers into the deep parts of the cages. I11 this position the rollers are out of contact with the driving member 7 and are, therefore, not rolled in their cages.

In the modification shown in Figs. 3 and 4, there is an independently-rotatable part 27 mounted on the shaft 4 on the ball-bearing 28. This part has a disk portion intermediate the driving member 7 and the driven member 8, and carries the pivoted pawls 29. The driving member 7 has internal engaging points, and the driven member 8 has external engaging points, the pawls 29 being mounted in slots in the intermediate part in such a manner that they may engage the engaging points of both members to operatively connect them. The springs 30 are permitted to force the pawls to their inclined position, shown in Fig. 4, out of contact with the driven members, when the brake 32 is not applied to the friction surface 31. However, when the switch 13 is closed by the electromagnet, the pivoted lever 17 moves the brake into engagement with the friction surface 31, retarding the rotation of the disk 27 relatively to the driving member 7, and thereby turning the pawls 29 on their pivots until they engage the engaging points of the driven member 8 while still engaging the engaging points of the driving member 7. The spring 33 forms a resilient buffer between the armature shaft 36 of the electromagnet and the pivoted lever 17. As soon as the switch 13 is opened, the brake 32 is re leased and the springs 30 force the pawls out of contact with the engaging points of the driven member 8.

In Fig. 5, the speed change lever 34 closes the switch 13, and applies the brake 32 to the friction surface 31 of the intermediate part 27, when it is moved to a starting position. At this time, the over-running clutch transmits power from the motor 5 to the shaft 4. At all other positions of the speed change lever, the switch 13 is opened, so that the battery is disconnected from the motor.

Having thus described my invention, what I claim is:

1. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, a connecting element movable to connecting position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; starting mechanism for driving the driving member to start the engine; and means which, upon starting the starting mechanism into operation, moves the disengaging mechanism to cause the connecting element to move into connecting position, and which, upon discontinuing the operation of the starting mechanism, moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

2. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, a connecting element movable to connecting position in'which the two members rotate as a unit, and disengaging mechanism for the connecting element; a starting motor for driving the driving member to start the engine; and means which, upon starting the starting motor into operation, moves the disengaging mechanism to cause the connecting element to move into connecting position, and which, upon discontinuing the operation of the starting motor, moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

3. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven mem bers, a connecting element movable to connecting position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; a starting motor for driving the driving member to start the engine; a source of power supply for the motor; and a contro ler which, upon connecting the source of power supply to the starting motor, moves the dlsengaging mechanism to cause the connecting element to move into connecting position, and which, upon disconnecting the source of power supply from the motor, moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

4. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, a connecting element movable to connecting position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; an electric starting motor for driving the driving member to start the engine; a battery; and a switch which, upon connecting the battery and motor, moves the disengaging mechanism to cause the connecting element to move into connecting position, and which, upon disconnecting the battery from the motor, moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

5. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, a connecting element movable to connecting I position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; an electric starting motor for driving the driving member to start the engine; a battery; an electromagnetic switch which, upon energization, connects the battery to the motor and moves the disengaging mechanism to cause the connecting element to move into connecting position, and which, upon denergization, disconnects the motor from the battery and moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

6. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, a connecting element movable to connecting position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; an electric starting motor for driving the driving member to start the engine; a battery; an electromagnetic switch which, upon energization, connects the battery to the motor'and moves the disenagaging mechanism to cause the connecting element tomove into connecting position, and which, upon deenergization, disconnects the motor from the battery and moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members; and a switch and electrical connections between the battery and the electromagnetic switch for energizing the winding thereof at will.

7. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members, an independently rotatable intermediate part, a connecting element carried by the intermediate part and movable to connecting position in which the two members rotate as a unit, and disengaging mechanism for the connecting element; starting mechanism for driving the driving member to start the engine; and means which, upon starting the starting mechanism into operation, moves the disengaging mechanism to cause the connecting element; to move into connecting position, and which, upon discontinuing the operation of the starting mechanism, moves the disengaging mechanism to cause the connecting element to move out of contact with one of the two members.

8. In a starting system for internal combustion engines; an overrunning clutch comprising coaxial driving and driven members with opposed engaging points, an independently-rotatable intermediate part, a connecting element carried by the intermediate part and movable to connecting position in which the two members rotate as a unit, and a spring tending to hold the connecting element out of contact with the engaging points of one of the two members; a brake adapted to frictionally contact with the intermediate part to retard its rotation and thereby engage the connecting element with the engaging points of both members against the action of the spring; starting mechanism for driving the driving member to start the engine; and means which, upon starting the starting mechanism into operation, positively moves the brake into contact with the intermediate part, and which, upon discontinuing the operation of the starting mechanism, positively holds the brake out of contact with the intermediate part.

In testimony whereof I afiix my signature in presence of two witnesses.

FRANZ KRATZ.

Witnesses:

WILLIAM STRUss, FREDERICK HOYERMAUER.