US2919770A - Spring-actuated starter for internal combustion engines - Google Patents

Description

Jan. 5, 1960 M. P. ROGGENDORFF 2,919,770

) SPRING-ACTUATED STARTER FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14, 1957 4 Sheets-Sheet} INVENI'OR Mar/'1' PPOGGf/VDOR 5, 1960 M. P. ROGGENDORFF SPRING-ACTUATED STARTER FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14, 1957 4 Sheets-Sheet 2 lNVt'NTOE Mar/in poaamwap Jan. 5, 1960 M. P. ROGGENDORFF 2,919,770}

SPRING-ACTUATED STARTER FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14, 1957 4 Sheets-Sheefi 3 FIG 3 INVENTOR fluff/"r P EUGGENDOPF Jan; 5, 1960 M. P. ROGGENDORFF 2,919,770

SPRING-ACTUATED STARTER FOR INTERNAL COMBUSTION ENGINES Filed Jan. 14, 1957 4 Sheets-Sheet 4 INVENTOP Mar/in PPOGGfNDO/QF 2,919,770 Patented Jan. 5, 1960 nice SPRING-ACTUATED STARTER FOR INTERNAL COMBUSTION ENGINES Martin P. Roggendorfi, Porz, Germany, assignor to Kliicker-I-Iumboldt-Deutz Aktiengesellschaft, Koln, Germany Application January 14, 1957, Serial No. 634,001 Claims priority, application Germany January 21, 1956 9 Claims. (Cl. 185-41) The present invention relates to a starter for an internal combustion engine with power-storing spring having one end connected to a stationary part and having its other end connected to a rotatable part adapted to be rotated by actuating means or a winding device including wheel connected to the crank shaft of the engine. This heretofore known spring starter works in such a way that the fly-wheel having peripheral teeth engageable by said pawls is by means of said actuating means first rotated by steps in a direction counter to the normal direction of rotation of the fly-wheel, whereby the spring is wound up. After the spring has been Wound, the said actuating means is made ineffective, i.e. is brought out of engagement with said peripheral teeth, whereby said spring rotates said fiy-wheel in normal direction of rotation.

The heretofore known spring-actuated starters have the drawback that the one or other pawl may during the operation of the fiy-wheel move back into a position in vwhich it engages the teeth of the fly-wheel whereby considerable disorders may be caused.

It is, therefore, an object of the present invention to provide a spring-actuated starter for internal combustion engines, which will overcome the above mentioned drawback.

It is another object of this invention to provide a spring-actuated starter for internal combustion engines, in which the spring will positively prevent any accidental movement of the pawls into operative position during operation of the engine.

It is also an object of this invention to provide a springactuated starter for internal combustion engines, in which the spring will block any accidental movement of the pawls into operative position even if the spring should be accidentally partly wound while the engine is in operation.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

Fig. 1 is a vertical cross section along the line I-I of Fig. 3 through a spring-actuated starter for internal combustion engines according to the present invention, the spring of said starter being shown in expanded position.

Fig. 2 is a cross section similar to that of Fig. 1, however with the starter spring in wound-up condition.

Fig. 3 shows the starter according to the invention installed in or connected to a one-cylinder internal combustion engine, the starter being shown in section while the engine is shown in view.

Fig. 4 is a partial section along the line IV-IV of Fig. 2.

Figs. 5 and 6 illustrate on an enlarged scale a pawl and lever mechanism of the arrangement of Figs. 1 and 2 in closed and open position respectively.

Fig. 7 represents a modification of a portion of Figs. 1 and 2 according to which modification the spiral spring of Figs. 1 and 2 when in released position directly engages the pawl.

General arrangement The spring-actuated starter according to the present invention has one end connected to a stationary part and its other end connected to a rotatable part adapted to be actuated by a winding device and also adapted by means of a pawl to be coupled with or disconnected from the teeth of a disc or wheel for instance a fly-Wheel connected to the crankshaft of the engine. The spring-actuated starter according to the invention is characterized primarily in that the movement of the spring during the winding up or the expansion of the spring initiates the movement of the pawl for coupling or uncoupling action by causing the pawl either directly or through theintervention of an intermediate member to engage a winding of the spring and to be actuated by the movement thereof. Due to the fact that the power-storing spring will following the starting of the internal combustion engine be in expanded position, it occupies a position in which it blocks any movement of the pawl or any possible intermediate members. Thus, with the arrangement according to the present invention the pawl is prevented from moving during the operation of the internal combustion engine and consequently from engaging the teeth by means of which the coupling with the crankshaft is established. The safety blocking against undesired movement of the pawl into effective position exists even if, during the operation of the internal combustion engine, the spring-actuated starter is accidentally partly wound up. At any rate, with the arrangement according to the present invention, it is completely impossible that the pawl suddenly moves from its ineffective position into effective position and thereby causes damage.

Structural arrangement Referring now to the drawings in detail, the springactuated starter shown therein comprises a spiral spring 1 having its inner end 2 connected to a stationary hub 3 and having its outer end 4 in engagement with a rotatable segment 5. As will be evident from Fig. 3, the hub 3 consists of three annular members which by means of screws 6 and 8 are connected to the crank case 11 on the outside of the bearing 9 for the crankshaft 10. The segment 5 is mounted on the right-hand annular member (Fig. 3) of hub 3. The spiral spring 1 consists of two equal halves 1 and 1". With reference to Fig. 3, one of said halves is arranged on the left-hand side and the other half is arranged on the right-hand side of segment 5. The hub 3 is divided into three annular members in such a manner that the spring portion 1 engages the central annular member, whereas the spring portion 1" engages the right-hand annular member.

In this connection it is to be understood that the invention is not limited to the employment of a spiral spring. The essence of the invention consists in that the coupling pawl for the spring-actuated starter is independent in its movement fromthe movement of the power-storing spring and that the arrangement according to the invention with all its advantages is also applicable to other spring types such as helical springs,

tension or pressure springs.

The internal combustion engine shown in Fig. 3 to which the spring-actuated starter according to the invention is connected represents an air-cooled one-cylinder two-cycle diesel engine. However, the spring-actuated starter mechanism according to the invention is not limited to this particular type of internal combustion en gmes.

The crankshaft bearing 9 is arranged adj cent the fiy-wheel 12 of the engine, said fly-wheel forming a power transmitting member for conveying power from the spiral spring 1 to the crankshaft it) as will presently appear. The fly-wheel 12 has a hub 13 which extends through the bore of the hub 3 and by means of screws 14 is connected to the crankshaft (Fig. 3). The flywheel 12 has a flange 15 provided on the inside thereof with teeth 16. As will be seen from Fig. 3, the teeth 16 are located in the transverse plane of the machine in which also the spring portion ll" is located.

The diesel engine shown in Fig. 3 is provided with a cylinder 18 equipped with cooling fins 17. The cylinder head of the cylinder 18 is suspended by screws 20 in a bell-shaped portion 19. The bell-shaped portion 19 is by means of screws 21 connected with the crankcase l1 and additionally serves as guiding means for cooling air delivered by a blower 22 drivingly connected with the crankshaft of the engine. In front of the blower 22 there is provided the fuel injection pump 23 which is drivingly connected with the crankshaft and which through pressure conduit 25 communicates with the fuel injection nozzle 24 in the cylinder head.

The segment 5 is adapted to be moved about the axis of shaft ill) by actuating means such as a winding device known per so which has two pawls 26 and 27. These pawls are adapted to be actuated by means of a manually operable lever 37 in such a manner that they will alternately in the direction of the arrow a in Fig. l engage teeth 23 of the segment 5 and rotate the latter in the direction of the arrow or while the segment 5 through the intervention of a bolt 29 will advance the adjacent end of the spiral spring 1 and thereby will wind up the latter. Thus, the segment 5 is prevented from moving backwards during the winding-up operation, namely once by pawl 2s and another time by pawl 27, then again by pawl 26 etc., said pawls alternately advancing and returning. The bolt 29 is fastened in the segment in such a manner that the outer ends 4 of the spring portions 1 and 1" will engage the bolt 29 in a hook-like manner. A bolt 30 serves to maintain the hook-like end of the spring portions in their relative positions in which they engage the bolt 29. The winding device is so designed that by means of the latter it is possible, provided the spring has been suificiently wound up, to move the pawls 26 and 27 into the position shown in Fig. 1 so that the segment and thus the spiral spring 1 is released. Fig. 2 illustrates the position of the winding-up device in which the spring sufficiently wound up, the two pawls 26 and 2.7 engage the teeth 28 of the segment 5.

In order to make possible that the spiral spring ll can start the diesel engine, the segment 5 is provided with a pawl 31 which is adapted to be coupled with and uncoupled from the teeth 16 of the fly-wheel 12. As will be evident from Fig. 4, the pawl 31 is by means of a bolt 32 mounted on that side of the segment 5 on which it is located in that transverse plane of the engine in which also the teeth 16 are located. The power of the two spring portions 1' and l" can thus through pawl 31 be conveyed to the flywheel 12.

The spring-actuated starter according to the invention is particularly characterized in that when tensioning or expanding the spiral spring 1 or its portion 1', the spring initiates the movement of the pawl 31 for engagement with or disengagement from the teeth 16 by causing the pawl 31 to engage the spring portion 1". This is effected through the intervention of a member, namely the double-arm lever 33, which on one hand controls the coupling of the pawl 31 with the teeth 16 and on the other hand the uncoupling of the pawl 31 from the teeth 16. As will be seen from Fig. l, the double-arm lever 33 which is mounted on segment 5 by means of a bolt 34 rests against the outside of the outer winding of the spring portion 1" when the spiral spring is in expanded condition. The pawl 31 and the two arm lever 33 are under the influence of springs 35 and 36 which become effective when the spiral spring It moves. The force of the spring 36 is so selected that it exceeds the thrust of the spring 35. The purpose of the spring 35 consists in making sure that the pawl 31 will remain in contact with the two arm lever 33.

The operation of the pawl 31 and the double-arm or the two-arm lever 33 is as follows: when the spiral spring ll is wound up by means of the winding-up device, it contracts and each of its windin s moves toward the longitudinal central axis of the crankshaft. As a result thereof, the outer winding which normally contacts the twoarm lever 33 moves away from the latter so that said lever 33 will move under the influence of spring 36 in such a manner that the two-arm lever 33 moves the pawl 31 toward the outside and causes the latter to engage the teeth 1-6 of the fly-wheel l2. The spring 36 may be made so strong that the pawl 31 will be able to move the engine while the spiral spring l is being wound up so that the engine is moved from its position of stationary friction into the position of movable friction.

Fig. 2 shows pawl in engagement with the teeth As will be clear from Fig. 2, pawl 31 and the two- 'm lever 35 occupy a position defining with each other roof-like shape when the pawl 3i. engages the teeth 6. in this position, one end of the two-arm lever 33 ngages a depression of the pawl 31 thereby blocking the pawl 31 so that when winding up the spiral spring 1, the movement of the engine is absolutely assured.

When by means of the windingup device in the manner set forth above the segment 5 and consequently also the spiral spring 1 is released, the engine will be started through the intervention of the pawl 31 and the teeth 16 of the fly-wheel 12. With this release of the segment 5 and spiral spring 1, the spiral spring it again expands, in other Words the spacing between the spirals of the spring increases again. This expanding movement of the spiral spring causes return of the two-arm lever 33 to its starting position shown in Fig. 1 in which the lever 33 will then be safely held. When the diesel engine begins to overtake the fly-wheel, the pawl 31 is released and due to spring 35 moves into the position shown in Fig. 1 in which it will then be held. The pawl 31 will neither due to the centrifugal force nor by the eifect of a counterweight have the possibility to move during the operation of the engine into its effective position. The movement of the pawl 31 can be effected merely by the two-arm lever 33 which, however, during the operation of the internal combustion engine is locked in its position shown in Fig. 1.

It may be added that the invention is not limited to an arrangement according to which a two-arm lever is interposed between the spiral spring and the pawl. It is also possible that the spiral spring when in its expanded condition has one Winding in direct contact with a pawl 31a as shown in Fig. 7.

It is also to be understood that the present invention is, by no means, limited to the particular construction shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. in a spring-actuated starter for internal combustion engines having a crankshaft and a power-transmitting member rotatably connected to said crankshaft, the combination of: a stationary member, a movable member, starter spring means having one end connected to said stationary member and having the other end connected to said movable member, actuating means arranged adjacent said movable member and operable to actuate the same for moving said starter spring means from its normally expanded position into tensioned position, a coupling member carried by said movable member and continuously urged into coupling engagement with said power transmitting member to thereby couple said starter spring means with said power-transmitting member,

said starter spring means when in tensioned position being adapted to convey starting power to said crankshaft throughsaid coupling member when the latter is in engagement with said power-transmitting member, said starter spring means when in expanded position acting upon said coupling member so as to prevent accidental movement of the latter into coupling engagement with said power-transmitting member.

2. In a spring-actuated starter for internal combustion engines having a crankshaft, and a fly-wheel rotatably connected to said crankshaft and provided with a gear ring, the combination of: a stationary member, a movable member, starter spring means interposed between said stationary member and said movable member and having one end connected to said stationary member and having the other end connected to said movable member so as to be movable therewith, said movable member-having a peripheral surface provided with teeth, pawl means operable selectively to engage said teeth for step-wise moving said movable member in a direction for tensioning said starter spring means to thereby move said starter spring means from its normally expanded position into tensioned position, a coupling lever carried by said movable member, a first spring associated with said coupling lever and continuously urging the same toward said starter spring means into ineffective position, a second spring stronger than said first spring and operable to move said coupling lever into engagement with said gear ring for establishing driving connection between said fiy-wheel and said starter spring means through said movable member, said starter spring means being arranged when in its expanded position to prevent said second spring from moving said coupling lever into its gear ring engaging position.

3. In a spring-actuating starter for internal combustion engines having a crankshaft, and a fly-wheel rotatably connected to said crankshaft and provided with a gear ring, the combination of: a stationary member, a movable member, starter spring means interposed between said stationary member and said movable member and having one end connected to said stationary member and having the other end connected to said movable member so as to be movable therewith, said movable member having a peripheral surface provided with teeth, pawl means operable selectively to engage said teeth for stepwise moving said movable member in a direction for tensioning said starter spring means to thereby move said starter spring means from its normally expanded position into tensioned position, a coupling lever carried by said movable member, a first spring associated with said coupling lever and continuously urging the same toward said starter spring means into ineffective position, a two-arm actuating lever pivotally supported by said movable member and having a first arm for continuous engagement with said coupling lever and having a second arm for engagement with a winding of said starter spring means when the latter is in its expanded position to thereby prevent said actuating lever from actuating said coupling lever, and a second spring stronger than said first spring and continuously urging said actuating lever into position for moving said coupling lever into engagement with said gear ring, said actuating lever being operable in response to said spring winding disengaging said actuating lever to move said coupling lever into engagement with said gear ring for establishing coupling connection between said starter spring means and said fly-wheel through said movable member.

4. In a spring-actuated starter for internal combustion engines having a crankshaft and a power-transmitting member rotatably connected to said crankshaft, the combination of a central stationary member, a movable member coaxially arranged with regard to said stationary member in spaced relationship thereto, spiral starter spring means interposed between said stationary member and said movable member and having one end connected to said stationary member and having its other end connected to said movable member so as to'be movable therewith from an ineffective position to an efiiective position and vice versa, a coupling member pivotally supported by said movable member and movable from an ineffective position in which it engages a winding of said spiral spring means into effective position for establishing coupling connection between said power-transmitting member and said spiral spring means through said movable member, said spiral spring means when having said winding in engagement with said coupling member preventing movement of said coupling member into coupling engagement with said power-transmitting member, auxiliary spring means continuously urging said coupling member into coupling engagement with said power-transmitting member and being operable to move said coupling member into coupling engagement with said powertransmitting member in response to the disengagement of said coupling member when said spiral spring means moves from its ineffective position to its effective position, and means operable selectively step-wise to move said movable member for moving said spiral spring means from its ineffective position into its effective position to tension said spiral spring means.

5. In a spring-actuated starter for internal combustion engines having a crankshaft and a power-transmitting member rotatably connected to said crankshaft, the combination of: a central stationary member, a movable member coaxially arranged with regard to said stationary member in spaced relationship thereto, spiral starter spring means interposed between said stationary member and said movable member and having one end connected to said stationary member and having its other end connected to said movable member so as to be movable therewith from an ineffective position to an effective position and vice versa, a coupling lever pivotally supported by said movable member and movable from an ineffective position into an effective position for establishing coupling connection between said power-transmitting member and said starter spring means through said movable member, an auxiliary lever pivotally supported by said movable member and having one arm interposed between said coupling lever and said spring means and having its other arm in engagement with a winding of said spring means when the latter occupies its ineffective position, and additional spring means operable in response to the movement of said starter spring means from its ineffective to its effective position to cause said auxiliary lever to move said coupling lever into coupling engagement with said power-transmitting member.

6. A spring-actuated starter according to claim 5, in which said auxiliary lever tangentially engages the outside of the outer winding of said starter spring means when the latter occupies its ineffective position.

7. In a spring-actuated starter for internal combustion engines having a crankshaft and a power-transmitting member rotatably connected to said crankshaft, the combination of: a central stationary member, a movable member coaxially arranged with regard to said stationary member in spaced relationship thereto, spiral starter spring means interposed between said stationary member and said movable member and having one end connected to said stationary member and having its other end connected to said movable member so as to be movable therewith from an ineffective position to an effective position and vice versa, a coupling lever pivotally supported by said movable member and movable from an ineffective position into an effective position for establishing coupling connection between said power-transmitting member and said starter spring means through said movable member, first auxiliary spring means continuously urging said coupling lever into its ineffective position, an auxiliary lever pivotally supported by said movable member and having a first arm interposed between said coupling lever and said starter spring means and having a second arm in engagement With a winding of said starter spring means when the latter occupies its ineffective position, and second auxiliary spring means having one end connected to a portion of said starter spring means and having its other end connected to said second arm of said auxiliary lever, said second auxiliary spring means being stronger than said first auxiliary spring means and being operable in response to the movement of said starter spring means from its ineffective position to its effective position to cause said auxiliary lever to move said coupling lever into coupling engagement with said powertransmitting member, said starter spring means when returning to its ineifective position engaging said second arm to thereby withdraw said auxiliary lever from its position in which it causes said coupling lever to engage said power-transmitting member whereby said first auxiliary spring means withdraws said coupling lever from engagement with said power-transmitting member.

8. A spring-actuated starter according to claim 7, in which that side of said coupling lever which faces the first arm of said auxiliary lever is provided with a cutout to be engaged by said first arm when the latter holds said coupling lever in its coupling position thereby locking said coupling lever.

9. In a spring-actuated starter for internal combustion engines having a crankshaft and power-transmitting member rotatably connected to said crankshaft, the combination of: a stationary member, a movable member, spiral starter spring means composed of two substantially evenly strong spiral springs respectively arranged on opposite sides of said movable member, each one of said spiral springs having one end connected to said stationary member and having the other end connected to said movable member, actuating means arranged adjacent said movable member and operable to actuate the same for moving said starter spring means from its normally expanded position into tensioned position, a coupling member carried by said movable member and continuously urged into coupling engagement with said powertransmitting member to thereby couple said starter spring means with said power-transmitting member, said starter spring means when in tensioned position being adapted to convey starting power to said crankshaft through said coupling member when the latter is in engagement with said power-transmitting member, said started spring means when in expanded position acting upon said coupling member so as to prevent accidental movement of the latter into coupling engagement with said power-transmitting member. I

References Cited in the file of this patent UNITED STATES PATENTS 2,744,586 Blankenburg May 8, 1956

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