US2193012A - Engine starting mechanism - Google Patents

Description

Marci. 12, 1940.. F, STE N 2,193,012

ENGINE smmme MECHANISM Filed March 9, 1939 INVENTOR.

BY Fred 4.37%?

- ORN Patented Mar. 12, 1940 UNITED STATES ENGINE srm'rme MECHANISM Fred A. Stein, Jersey City, N. J., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application March 9, 1939, Serial No. 260,819

10 Claims. (Cl. 123-179) This invention relates to engine starting mechanism, and particularly to starting mechanism of the character in which a rotatable starting element moves into engagement with a rotatable engine shaft to impart initial rotary movement to the latter, concurrently with the supplying of fuel thereto. 7

An objectof the invention is to provide, in an engine starter of the character indicated, novel means for storing energy in a starter part, for

subsequent delivery to the engine-engaging starting element above referred to.

Another object is to provide novel means for preventing release of any of the stored energy, 16 except at the discretion of the operator.

A third object is to provide novel means for preventing premature movement of the actuating element (which may be a manually rotated crank element) in a direction opposite to the energy storing direction.

These and other objects of the invention will become apparent from inspection of the following specification when read with reference to the accompanying drawing wherein is illustrated the preferred embodiment of the invention. It is to be expressly understood, however, that the drawing is for the purpose of illustration only, and is not designed as a definition of the limits of the invention, reference being had to the appended 80 claims for this purpose.

'In the drawing:

Fig. 1 is a central sectional view of a device embodying the inv'ntion; and

' Fig. 2 is a second sectional view, taken on the 83 line 2-2 of Fig. 1.

In the drawing reference character Sdesignates the engine-engaging element, 6 is a piston equipped with a cup-shaped or skirted sealing element attached to its upper surface (the sealing element being. "Victorprene or an equivalent composition), 1 is a cylinder housing the piston 6,

8 is a hand-crank constituting a suitable form of energizing element, and 9 is a housing for the entire mechanism, said housing including, in addition to the cylinder supporting section, a gear supporting section III having a laterally extending boss ll constituting a support, and presenting a cylindrical bearing surface for a hollow shaft 12 rotatable therein in response to manipulation by the operator of the hand-crank 8 which is operatively connected to the hollow shaft I2 by any suitable means such as the pin indicated at teeth of the planet pinions l1 and I8 are in mesh.

The means for preventing release of any energy 10 stored in the cylinder I by reason of the movement imparted to piston 6 by way of the planetary drive just described, except at the discretion of the operator (so that the operator may determine the time of application of the energy to the 15 engine-engaging element 5 for engine cranking purposes) is shown in the drawings as including a spring biased detent element 2| normally fitting into the recess 22 in the outer periphery'of the annulus l9 and retractible from said recess by means 23 registering with the head portion 24 of the stem 25 of the detent, whereby the detent may be lifted against the yielding opposition of the spring 28 which at its upper end abuts a plate 2'I-integrated with the housing 9 through 25 35- The means Ior preventing premature movement of the manually operated actuating element 8 in a direction opposite to the energy storing direction is shown in Figure 2 as being constituted by a plurality of yieldable detents or pawls 33 each of which has limited rocking movement about a supporting pin 34, the said pins being integrated with the planetarycarrier 36 (shown best in .Figure 1) from-which carrier the pins 34 extend laterally to receive the pawls 33. 4 By a clockwise rotation of the actuating handie 8 and the sun gear l6 secured thereto, there is produced counterclockwise rotation of the planet pinions l1 and It (as viewedin Fig. 2)

and this causes the planet carrier 36 to move in a 50 in form of hollow rivets or bushings suitably in tegrated with the planet carrier 38. During this clockwise rotation of the planet carrier 36 the pawls 33 ride freely along the teeth of the annulus l9 and a drive is thereby imparted to the downwardly extending rack portion 46 integrated with the piston 6, the driving connections being 7 shown as constituted by the pinion teeth 41 out shaft 48 is communicated to the engine-engaging element 5.

With the construction and inter-relationship ofthe parts as above indicated it will be apparent that rotation of the actuating handle 8 in the indicated direction (and assuming detent 2| to be in engaged position) will cause a lifting of the rack 46 and hence a movement of the piston 6 upwardly in the cylinder 1 to produce a progressively increasing pressure upon the air (either 7 pre-compressed or atmospheric) which is confined therewithin, having previously been admitted thereto through the normally closed inlet port controlled by the valve element 65. During this compression of air in the cylinder I the engine-engaging element 5 rotates with the transmission shaft 48 .due to the splined connection 6| previously described, but no movement thereof in the engine-engaging direction-that is, in a direction to the right along its axis-occurs, because there is no means to translate the rotary movement of the shaft 48 into a longitudinal movement of the engine-engaging member 5 so long as the direction of the rotation of transmission shaft 48 is counterclockwise as viewed from the right of Figure 1. Thus energy will be stored in the cylinder 1 in an amount commensurate with the degree of compression of the air which is trapped in the chamber above the piston 6.

Subsequently, when it is desired to release the energy thus stored and to transfer said energy to the engine by way of the engine-engaging element 5, the operator swings the releasing element 23 in a counterclockwise direction about its pivot 28 and thereby withdraws detent 2| from looking relationship to the annulus 19. The annulus I9 is thereby made free to rotate with the planet pinions I! and I8, both of which are carried along with the annulus l9, and the planet carrier 38 as the pinion 41 of transmission shaft 48 is rotated in a clockwise direction (as viewed from the right of Figure 1) by the descent of the rack 46 and piston 6 under the impetus of the expanding charge of compressed air above the piston; the air being now free to expand by reason of the release of the locking means 2|. The resultant rotation of the transmission shaft 48 is in the proper direction to produce translation of motion in a longitudinal direction by reason of the action of the pin ll upon the diagonal slot in the friction element 12. As in patent to R. Chilton, No. 1,958,657 granted May 15, 1934, this slotted friction sleeve has a sufficiently tight grip upon the cylindrical portion 62 of the engine-engaging element 5 to be rotated therewith and hence to produce a camming thereof toward the engine-engaging position. The diagonal slot in the member 12 rides along the pin H until the engine-engaging member 5 reaches full engineengaging position, after which the continued rotation of the engine-engaging member 5 (slip ping freely within friction element 12) causes a cranking of the engine, while the friction element 12 remains stationary.

At the termination of the cranking actionthe engine having by this time become sufliciently self-operative to accelerate beyond the speed of the engine-engaging member 5the resulting overrunning action causes a reverse camming of the engine-engaging member 5, and in conjunction therewith the coiled compression spring 11 operates to insure a return of the engine-engaging member 5 to the disengaged position indicated in the drawings; the spring 11 being held against an axially fixed abutment 18 at its outer end, and at its inner end having a bearing against the flange 19 on the connecting pin 8| by which the thrust of the spring is imparted to the engineengaging member 5 by Way or the intervening retaining nut 82. The detent 2! is now allowed to return to normal position and the starter is thus made ready for subsequent use in storing a new supply of energy in cylinder 1 upon repetition of the cycle of operations heretofore described.

What I claim is;

1. In an engine starting mechanism, the combination with an engine-engaging member of driving means therefor including a transmission shaft splined to said engine-engaging member at one end, means engaging the opposite end of said transmission shaft for rotating said shaft and engine-engaging member in a direction which prevents movement of the engine-engaging memher to engine-engaging position, means for lock ing said shaft against rotation in the cranking direction, and means operative upon release of' said locking means to rotate said transmission shaft and engine-engaging member in the cranking direction.

2. In an engine starting mechanism, the combination with an engine-engaging member of driving means therefor including a transmission shaft connecting with said engine-engaging member at one end, means connecting with the opposite end of said transmission shaft for rotating said shaft and engine-engaging member in a direction which prevents movement of the engine-engaging member to engine-engaging position, means for locking said shaft against rotation in the cranking direction, and means operative upon release of said locking means to rotate said transmission shaft and engine-engaging member in the cranking direction, said lastname'd means including a cylinder having a piston slidable therein, and motion translating means connecting said shaft and piston.

3. In an engine starting mechanism, the combination with an engine-engaging member of driving means there-for including a transmission shaft connecting with said engine-engaging member at one end, energizing means connecting with the opposite end of said transmission shaft for rotating said shaft and engine-engaging member in a direction opposite to the cranking direction, and means operative to rotate said transmission shaft and engine-engaging member in the cranking direction, said last-named means including a cylinder, and means in said cylinder for trapping air under a pressure which is proportional to the degree of rotation imparted to said transmission shaft by said energizing means.

4.-In an engine starting mechanism, the combination with an engine-engaging member of driving means therefor including a transmission shaft connecting with said engine-engaging member, means for locking said shaft against rotation in the cranking direction, said locking means including an internally toothed planetary gear, a planet carrier having a locking element engageable with the teeth of said gear, and an additional locking means engageable with the outer surface of said gear to hold said gear against rotation in either direction, and thereby restricting rotation of said planet carrier, and hence said transmission shaft, to the non-cranking direction, and means for releasing said locking means.

5. In an engine starting mechanism, the. combination with an engine-engaging member of driving means therefor including a transmission shaft connecting with said engine-engaging member, means for locking said shaft against rotation in the cranking direction, said locking means including an internally toothed planetary gear, a

- planet carrier having a locking element engageable with the teeth of said gear, and an additional locking means engageable with the outer surface of said gearto hold said gear against rotation in either direction, and thereby restricting rotation of said -planet carrier, and hence said transmission shaft, to the non-cracking direction, means for releasing said locking means, and means operative upon such release to rotate said shaft and engine-engaging member in the cranking direction.

' 6. In an engine starting mechanism, the combination with an engine-engaging member of driving means therefor including a transmission shaft connecting with said engine-engaging member, and means for locking said transmission shaft againstrotation in the cranking direction, said locking means including an internally toothed gear, a, locking element engageabie with the teeth of said gear, an additional locking means engageable with the outer surface of said gear, and means for causing said first-named locking element and said shaft to move as a unit in both directions of rotation.

'I. In an engine starting mechanism, the combination with an enginemember of driving means therefor including a on means comprising a member carrying planetary gears meshing with said internally toothed gear,

and also carrying mounting means for said locking element.

8. In an engine starting mechanism, the combination with a transmission shaft of means for restricting said shaft to uni-directional rotation, said means including a planetary gear, a pawl engageable with the teeth of said gear, a pawl carrier on which said pawl is pivotally mounted, said pawl carrier having a driving connection with said shaft, and torque transmitting means including planet gears meshing with said flrstnamed gear and carried by said pawl carrier.

9. In an engine starting mechanism, the combination with a transmission shaft of energizing means for rotating said shaft in a direction op posite to the cranking direction, and means operative to rotate said transmission shaft in the cranking direction, said last-named means including a cylinder, and means in said cylinder for trapping air under a pressure which is proportional to the degree of rotation imparted to said transmission shaft by said energizing means.

10. In an engine starting mechanism, the combination with a transmission shaft of energizing means for rotating said shaft in a direction op posite to the cranking direction, and means operative to rotate said transmission shaft in the cranking direction, said last-named means including a cylinder, means in saidcylinder for trapping air under a pressure which is proportional to the degree of rotation imparted to said transmission shaft by said energizing means, said means including a piston driven by said shaft in response to operation of said energizing means, and means engageable with said energizing means to prevent premature reversal of the pistons direction of travel, under the impetus of the trapped comair.

mam.

Images