US3686961A

US3686961A - Starting mechanism

Info

Publication number: US3686961A
Application number: US143932A
Authority: US
Inventors: Robert W Campbell
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1971-05-17
Filing date: 1971-05-17
Publication date: 1972-08-29
Anticipated expiration: 1989-08-29
Also published as: GB1345994A

Abstract

The housing of a starting motor rotatably mounts a cylinder having internal splines of one pitch. A shaft having external splines of a different pitch is rotatably and translatably supported by both the cylinder and housing and is connected at one end to a pinion engageable with the starter gear of an engine. Supported by the splines on the cylinder and the shaft are respectively a plunger and a nut that are advanced towards the pinion end of the shaft by the coaction of the cylinder and shaft with their respective different sets of splines. The plunger and nut are coupled by an axially acting clutch engaged by the translation of the plunger towards the pinion end and by a rotatably acting clutch engaged by rotation of the shaft relative to the cylinder. The rotatably acting clutch is disengaged by rotation of the shaft relative to the cylinder in the other direction or by the engagement of the axially acting clutch. Compressed between the nut and the pinion is a helical jump spring that not only translates the pinion when the nut is translated by the plunger but also allows the rotatably acting clutch to be disengaged should the teeth of the pinion abut those of the engine starter gear or should the engine starter gear drive the pinion rather than be driven by it. The jump spring also urges the pinion forward to engage the starter gear after the abutment has been eliminated. When the engine has started, the inertial interaction between the cylinder and plunger and a preload on the rotatably acting clutch retracts the plunger to engage another axially acting clutch that in turn retracts the pinion from engagement with the starter gear.

Description

United States Patent Campbell Aug. 29, 1972 [54] STARTING MECHANISM [72] Inventor: Robert W. Campbell, Anderson,

. Ind. I

[73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed? May 17, 1971 [21] Appl. No.: 143,932

52 US. Cl. ..74/7 R 511 Int. Cl ..F02n 11/02 58 Field of Search ..74/7 R, 7 c, 6

The housing of a starting motor rotatably mounts a cylinder having internal splines of one pitch. A shaft having external splines of a different pitch is rotatably andtranslatably supported by both the cylinder and housing and is connected at one end to a pinion engageable with the starter gear of an engine. Supported by the splines on the cylinder and the shaft are respectively a plunger and a nut that are advanced towards the pinion end of the shaft by the coaction of the cylinder and shaft with their respective different sets of splines. The plunger and nut are coupled by an axially acting clutch engaged by the translation of the plunger towards the pinion end and by a rotatably acting clutch engaged by rotation of the shaft relative to the cylinder. The rotatably acting clutch is disengaged by rotation of the shaft relative to the cylinder in the other direction or by the engagement of the axially acting clutch. Compressed between'the nut and the pinion is a helical jump spring that not only translates the pinion when the nut is translated by the plunger but also allows the rotatably acting clutch to be disengaged should the teeth of the pinion abut those of the engine starter gear or should the engine starter gear drive the pinion rather than be driven by it. The jump spring also urges the pinion forward to engage the starter gear after the abutment has been eliminated. When the engine has started, the inertial interaction between the cylinder and plunger and a preload on the rotatably acting clutch retracts the plunger to engage another axially acting clutch that in turn retracts the pinion from engagement with the starter gear.

9 Claims, 1 Drawing Figure Patented Aug. 29, 1972 I l N VEN TOR. i052 z z ZZZ Cam 05M A T T R/VE Y STARTING MECHANISM This invention relates to a vehicle starting mechanism of the type having two differently pitched helically splined drive members that are clutchable to rotate and translate an output shaft.

Starting mechanism using pitched splines to effect engagement of a pinion with the starter gear of an engine require an overrunning clutch where it is desired to protect the starting mechanism for the effects of overspeed created when the starting gear drives the pinion. Such clutches, however, do not disengage the starting motor fromrotating the pinion when the teeth of the pinion abut those of the starter gear or when the engine fires but does not start and ejects the pinion. In each of these conditions, if reengagement is subsequently attempted before both the pinion or the ring gear have stopped, the pinion driven by the starting motor, may possibly damage the starting gear by attacking or milling it.

In the present invention a single rotatably acting clutch is employed to decouple the rotation of the starting motor from that of the shaft carrying the pinion, not only when the teeth of the pinion abut those of the starting gear, but also when the pinion is driven by the engine after the latter has started or when the engine fires without starting. Such decoupling is obtained by a plunger housing driven by the starting motor and a shaft translating the pinion relative to the starting gear. A rotatably acting friction clutch couples the rotation of the plunger housing to the shaft and is supported and controlled by a pair of helically splined drive members in the form of a plunger and a nut. The cylinder translates and rotates the plunger through splines of a first pitch, and the nut drives, or is driven by, the shaft through splines of a second pitch. The plunger and nut are also connected by a pair of axially acting clutches, one such clutch being engageable to translate the shaft toward the starting gear and the other clutch engageable to retract the shaft.

A helical jump spring is compressed between the nut and the pinion so that the translation of the nut by the plunger is effective to translate the pinion towards the starting gear. To prevent the nut from translating to the starting motor end of the shaft and to allow the friction clutch to be fully engaged by the torque transmitted through the effects of the differently pitched splines, Belleville springs are compressed between the driving discs of the friction clutch and a stop shoulder on the motor end of the shaft. The Belleville springs preload the rotatably acting clutch so that the reaction between the splines on the plunger and housing cooperate to retract the plunger, and therethrough the shaft, when the engine starts and drives the pinion.

So that a slight forward translation of the nut relative to the plunger will disengage the friction clutch, the driving discs of the friction clutch are translatably connected to the plunger while the driven discs are fixed to the nut. Translation of the nut relative to the plunger to disengage the friction clutch is effected by a first axially acting clutch when the teeth of the pinion abut those of the starting gear or by the translation of the nut towards the pinion when the latter is driven by the starting gear.

It is therefore a primary object of the present invention to provide a rotary motion clutch that is disengageable to decouple the starting motor from the starting gear of an internal combustion engine when the pinion on a translatable output shaft of the starting mechanism abuts the starting gear and also when the starting gear drives the pinion.

It is another primary object of the present invention to provide a starting mechanism having a translatable output shaft to which rotary motion is coupled from an input device by means of a clutch that is translatable with and also relative to the shaft and that is engageable by translation in one direction relative to the shaft and disengageable by translation in the other direction.

It is a further object of the present invention to control the translation and engagement of a rotary clutch of the foregoing type by a plunger and a nut driveably connected respectively to the starting motor and translatable shaft by helical splines.

It is a further object of the present invention to provide a rotary clutch controlled by splined plunger and nut members of the foregoing type wherein one spring translates the shaft in response to the translation of the nut by the plunger and another spring translatable with the shaft cooperates with the nut to engage and disengage the clutch.

Further details, objects and advantages of the present invention will become apparent from the following description taken in conjunction with the single drawing which slows a longitudinal cross-section of an embodiment of the invention with the translatable shaft of the starting mechanism being shown in is retracted position.

With reference now to the drawing, there is shown an assembly 10 for coupling the starting motor 12 to rotate the starter gear 14 of an internal combustioneengine 16 by means of output means in the form of a drive pinion 18. Pinion 18 is affixed to one end of shaft 20 that carries Belleville springs 22 near the other end. Shaft 20 is translated towards starter gear 14 by a first axially acting clutch 24 and a helical jump spring 26 and is retracted by a second axially acting clutch 28 and an antidrift spring 30. Axially acting clutch 24 comprises a plunger or input member 32 and a nut or output member 34 that carry a rotatably acting friction clutch pack 36 therebetween for coupling the rotation of starting motor rotor 38 to a shaft 20 through input means in the form of a plunger housing 40. The plunger housing 40 has a set of quick pitch splines 42 for coating with plunger 32 to advance clutch 24. Shaft 20 has another set of splines 44 for backing nut 34 towards springs 22 to engage clutch 36 and for advancing nut 34 to disengage this clutch.

Assembly 10 is comprised of starting motor housing 46 suitably affixed to a drive housing 48, which in turn is suitably affixed to engine 16 and has a hub 50 with a bore 52 therethrough. Rotatably and translatably journaled in bore 52 is a cup member 54 having bearings 56 secured thereto by snap rings 57 and 58. Cup 54 is press fitted on pinion end 60 of shaft 20, the rotor end 62 of which is piloted in a drive hub 64 of rotor 38. Drivably connected to the exterior of drive hub 64 by splines 68 is plunger housing 40 having a cylinder 70 which is journaled by sleeve bearing 72 relative to drive housing 48 and is sealed relative thereto by suitable gland means 74.

A plurality of internal splines 42 of 70 right-hand pitch on cylinder 70 mate with similar splines 43 on the exterior of plunger 32. These splines couple the rotation of housing 40 to plunger 32. They also, when rotated in a direction opposite to their sense, translate the plunger from a position determined by wall 76 of plunger housing 40, corresponding with the disengaged position of pinion 18, to a position determined by snap ring 78 at the mouth of plunger sides 70, corresponding with the engaged position of pinion 18. When rotated in the same direction as their sense, splines 42 and 43 translate the plunger to the disengaged position where it is maintained while rotor 38 does not rotate by antidrift spring 30 compressed between snap ring 78 in the mouth of cylinder 70 and a shoulder 80 on plunger 32.

A plurality of external splines 44 of 45 right-hand pitch on shaft 20 mate with similar splines 45 on the interior of nut 34. These splines not only couple the rotation of nut 34 to shaft 20 but also, when rotated in a direction opposite to their sense, translate nut 34 over a length greater than the translation of plunger 32 between its engaged and disengaged positions. Nut 34 will translate towards pinion end 60 of shaft 20 when the interaction of the speed and splines thereof produce a sufficient force on nut 34 to overcome a preload exerted thereon by jump spring 26. Since it is desired to employ this mode of translating nut 34 when pinion 18 is driven by starter gear 14, such as when engine 16 has attained self-sustaining operation, the pitch of splines 44 and 45, as well as the preload and spring rate of jump spring 26, are selected to effect such translation only at speeds in excess of that at which rotor 38 drivesshaft 20.

Friction clutch pack 36 is comprised of a plurality of driving discs 90 and driven discs 92 the teeth of which are drivably connected respectively to drive splines 94 and 96 on plunger 32 and nut 34. To enable Belleville springs 22 to apply the requisite normal force to the working surfaces of the clutch pack 36, a Z-shaped circular clutch support plate 98 is splined to nut 34 and retained thereon by a snap ring 100, and a clutch backplate 102 is splined to plunger 32 on the rotor side of the clutch pack 36. Axial restraint for clutch backplate 102 to initially preload and ultimately fully load clutch 36 is provided by Belleville springs 22 retained by snap ring 112 in shaft 20 intermediate splines 44 thereon and rotor end 62 thereof by a collar 108 having a radial flange l 10.

Plunger drive splines 94 are longer than the axial length of clutch pack 36 to provide full drive connection therebetween when there is relative axial translation between plunger 32 and nut 34 upon forward translation of shaft 20 or operation of the clutch, as will be explained below. With this relative displacement between plunger 32 and nut 34 permitted by the relative length of splines 94, clutch 36 is preloaded, loaded, and unloaded entirely with reference to shaft 20 by the action of jump spring 26 acting on nut 34 and Belleville springs 22 acting on clutch plate 102.

The axial translation of plunger 32 relative to clutch discs 92 and clutch backplate 102 as well as relative to nut 34 is determined by first axially acting clutch 24 comprising circular flange 120 extending radially inward from plunger 34 and a circular flange 122. The latter extends radially outward from clutch support plate 98 and is integral therewith by an axial section 124. The outer diameter of flange 122 on one hand is less than the inner diameter of snap ring 78 by anamount sufficient to allow these elements to clear when translated to be in juxtaposition relative to each other. On the other hand, the outer diameter of flange 122 is greater than the inner diameter of flange 120 by an amount sufficient to allow the overlapping radial sections upon axial abutment therebetween to effect both a first axially acting clutch and also a second friction clutch, clutch 36 being the first friction clutch. Due to this overlap between flanges 120 and 122, the relative axial translation between plunger 32 and nut 34 is limited to the length of axial section 124. Moreover, further translation of plunger 32 causes flange 120 thereof to abut against flange 122 so as to prevent further axial translation of plunger 32 relative to nut 34 in the direction of pinion end 60. Subsequent to such abutment, further translation of plunger 32 towards pinion end 60 results in the corresponding translation of nut 34 until flange 120 abuts against stop ring 78. As described in further detail below, such abutted translation of nut 34 effects, through jump spring 26, the cor responding translation of shaft 20 including cup 54, pinion 18, and Belleville springs 22 carried thereby.

A second axially acting clutch 28 comprised of a seat in the rotor end of plunger 32 and circular flange 110 of collar 108 is engaged to retract shaft 20 and the elements carried thereby from the engaged position to the disengaged position by the effects of theinertial forces created on splines 42 and 43 when the engine starts to drive shaft 20 through ring gear 16 and pinion 18. When plunger 32 is thus translated to the disengaged position, pinion 18 is disengaged from starter gear 14 and retracted into the protective area within bore 52 of drive housing 48.

OPERATION Upon commencement of rotation of rotor 38, plunger 32 is caused to translate axially towards pinion end 60 through the inertial interaction between splines 42 and 43. Part of the torque available from rotor 38'is imparted to shaft 20 due to the preload exerted on the clutch by jump spring 26 and Belleville springs 22.

However, being slidably connected to plunger 32 by splines 94, driving clutch pack 36 and clutch backplate 102 do not translate towards pinion end 60 until flange of plunger 32 engages and axially clutches flange 122 of nut 34. Upon such clutch engagement, the translation of nut 34 through flanges 120 and 122 is communicated to shaft 20 through jump spring 26 and cup 54, thereby advancing pinion 18 towards starter or ring gear 14.

Should this translation be interrupted, such as by the abutment of the teeth of pinion 18 with those of starter gear 14, the forward acting forces imparted to plunger 32 by rotation of plunger housing 40' and splines 42 would be sufficient to continue the advancement of plunger 32, and therethrough nut 34, until flange 120 abutted snap ring 78. However, such advancement would be opposed or cushioned by the further compression of spring 26. Moreover, since Belleville springs 22 being afiixed to shaft 20 do not translate axially with plunger 32 when there is tooth abutment, the continued translation of plunger 32 and nut 34 towards pinion end 60 during such abutment completely unloads the preload otherwise applied to clutch discs 90 and 92 by springs 26 and 22. While clutch 36 is completely unloaded in this condition, the overlapping and abutting radial surfaces of flanges 120 and 122 acts as a rotatably acting friction clutch to couple some slight torque from rotor 38 to shaft 20. The overlap and torque transmitted therethrough is selected to overcome the normal force applied between pinion l8 and starter gear 14 due to the increased force applied by the spring 26 upon abutment and to rotate or index the teeth of pinion 18 out of abutment with those of gear 14. Upon clearance of the interference between the teeth, jump spring 26 acting between nut 34 and cup 54 advances pinion 18 from within bore 52 of housing 48 into full engagement with ring gear 14. In this manner the radial and axial clutching actions effected by flanges 120 and 122 provide the dual functions of unloading and thereby protecting clutch 36 during tooth abutment and also indexing pinion 18 to eliminate the abutment.

The cranking of ring gear 14 by pinion 18 then commences with clutch 36 being held in an engaged position determined by the abutment of flange 120 of plunger 32 with snap ring 78. Moreover, since the contact between flanges 120 and 122 causes the translation of shaft 20 and the elements carried thereby, as heretofore been described, flange 122 will be brought directly under snap ring 78 when flange 120 is stopped thereby. With the pinion, clutches and plunger in this engaged position, the resisting torque represented by the nonstarted engine results in the application of a torque between shaft 20 and plunger housing 40 that causes splines 42 and 44 due to their different pitches to apply an axial rearward jacking force on nut 34 and a forward jacking force on shaft 20. But, since the inertial reaction between the rotation of plunger housing 40 and plunger splines 42 and 43 holds plunger 32 against snap ring 78 and since, due to the difference in the pitches of the splines, this reaction is not overcome, plunger 32 is held in a position fixed with respect to the cylinder 70. The effect of the jacking force is therefore not to translate nut 34 towards rotor end 62, because such translation is prohibited by the abutment of flanges 120 and 122, but to cause a slight forward translation of shaft 20 relative to nut 34. Such forward screwing of shaft 20 in nut 34 correspondingly translates Belleville springs 22 relative to nut 34 and thereby increases the normal axial force applied by clutch backplate 102 to the driving and driven clutch discs 90 and 92. This permits clutch 36 to transmit torques up to the limit determined by the deflection characteristics of Belleville springs 22 and thereby allows the clutch 36 to couple the full torques of rotor 38 less than this limit to pinion 18.

Upon the tightening of clutch plates 90 and 92, pinion 18 cranks ring gear 14 to cause either a normal self-sustaining start of engine 16 or a partial start where the engine fires without attaining self-sustaining operation. In either event starter gear 14 will drive, rather than be driven by, pinion 18 at a speed greater than that normally developed by rotor 38. Provision is made to substantially unload clutch 36 and allow it to slip under the circumstances to protect clutch 36 as well as the internal drive train and rotor 38 from the effects of overspeed. This slippage is effected by the inertial reaction between nut and shaft splines 44 and 45 to translate nut 34 forward against jump spring 26 and away from Belleville springs 22. Such translation is permitted and also limited by the length of arm 26 linking clutch support plate 98 with radial flange 122.

Thus, while the rearward translation of nut 34 relative to plunger 32 is stopped by the abutment of flange with flange 122 during engagement of clutch 36, the forward translation of nut 34 relative to plunger 32 and therefore shaft 20 is permitted to disengage the clutch. Such forward translation of nut 34 is possible, even after flange 120 of plunger 32 is stopped by snap ring 78, since the outer diameter of flange 122 clears the inner diameter of both stop ring 78 as well as the bore 52 of drive housing 48. Flange 122 is therefore free to translate towards pinion end 60 for a distance determined by the length of arm 124. However, so that it does not limit the torque transmitted by clutch 36 the length of arm 124 is selected to be greater than the axial separation between nut 34 and collar 108 in their retracted positions, such separation in turn being greater than deflection between the preloaded and fully loaded conditions of springs 22.

Retraction of pinion l8 iseffected by the inertial process, pinion 18 to their disengaged positions. An-- A tidrift spring 30'thereafter maintains plunger 32 and therethrough shaft 20 in their disengaged positions against the motions of plunger 40 that might otherwise inadvertently advance the shaft when starter motor 12 is deactivated.

Thus, one function of Belleville springs 22 is to allow clutch 36 to couple torque from'rotor 38 to pinion 18 up to the limits determined by the springs. Another function is to protect the clutch and the internal drive train from torque transients in excess of these limits, as might be produced during a partial start or backfire condition. Another function, performed upon initial engagement of clutch 36 by the radial slippage of springs 22 with respect to clutch backplate 102, is to protect the clutches and the drive train from the effects of torque transients that would otherwise be experienced if the full kinetic energy of rotor 38 were coupled directly to shaft 20. Another important function of springs 22 is to cooperate with jump spring 26 to maintain a minimum preload on clutch 36 when the engine is started and thereby couple sufficient torque to plunger splines 42 and 43 to effect retraction of shaft 20. This preload is selected sufficiently low to effect a rate of retraction that avoids disengagement during a momentary partial start. During this condition pinion 18, with continued cranking of starting motor 12, is quickly cycled from a driving, to a driven, and back to a driving mode with respect to starter gear 14 as clutch 36 engages, slips, and reengages due to the translation of nut 34 relative to springs 22. However, the preload on clutch 36, while it must effect a retraction rate through plunger splines 42 and 43 slow enough to avoid disengagement during partial start operations, must be high enough to effect disengagement for longer durations of overspeed.

Thus with both full and partial start conditions of overspeed as with tooth abutment, shaft and nut splines 44 and 45 screw nut 34 forward to further deflect jump spring 26 and relax Belleville springs 22. In the case of overspeed, the translation of nut 34 relative to springs 22 is limited to retain a preload on clutch 36 while, in the case of tooth abutment, translation of nut 34 relative to springs 22 is substantially greater to where clutch 36 is entirely unloaded.

Having described one embodiment of the present invention, it is understood that the specific terms and examples are employed in a descriptive sense only and not for the purpose of limitation. Other embodiments of the invention, modifications thereof, and alternatives thereto may be used. I therefor aim in the appended claims to cover such modifications and changes as are within the true scope and spirit of my invention.

What is claimed is:

1. In a starting mechanism:

. rotatable input means;

. rotatable and translatable output means;

. a plunger member and an output member;

. a first set of helical splines for operatively connecting said input means with said plunger member to rotate and translate said plunger member, and a second set of splines for operatively connecting said output member with said output means to rotate and translate said output means;

e. first clutch means for selectively translating one said member with the other said member;

f. second clutch means for selectively coupling the rotation of said one member to said other member, said second clutch means translatable with said other member and engageable when said other member translates in one direction relative to said output means and disengageable when said other member translates in the other direction relative to the output means; and

g. spring means for engaging said second clutch means when said other member translates in said one direction relative to said output means and for restraining said translation of saidother member in said other direction.

2. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism being supported along an axis by a housing mountable in proximity to said rotatable means:

a. a cylinder rotatably mounted by said housing along said axis, said cylinder being drivably connected with said rotor and having a firs set of helical splines;

. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having a second set of helical splines and having drive means engageable with said rotatable means;

c. a plunger member received by one set of said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft;

(1. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member;

e. rotary motion clutch means connecting said plunger and nut members and being axially translatable by said nut member relative to said drive means, said rotary clutch means being disengageable by said axial translation of said nut member relative to said drive means and said cylinder and being engageable by the translation of said shaft relative to both said nut member and said cylinder; and

f. spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member. I

3. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism being supported along an axis by a housing mountable in proximity to said rotatable means:

a. a cylinder rotatably mounted by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of splines of a first predetermined pitch;

. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having a second set of helical splines of a.

second predetermined pitch different from said first pitch and having drive means engageable with said rotatable means;

.C. a plunger member received by one set ofv said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft;

e. rotary motion clutch means connecting said plunger and nut member and being axially translatable by said nut member relative to said drive means, said rotary clutch means being disengageable by said axial translation of said nut member relative to said drive means and said cylinder and being engageable by the translation of said shaft relative to both said nut member and said cylinder and by said different pitches of said splines; and

f. first spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member; and

g. second spring means for urging said nut member towards said first spring means from said drive means.

4. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means;

a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines;

. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having stop means, drive means, and a second set of helical splines therebetween, said drive means engageable with said rotatable means;

0. a plunger member received by one set of said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft;

. axially acting clutch means connecting said members for causing said plunger member to translate said nut member;

. rotary motion clutch means connecting said 5. In a starting mechanism for engaging rotatable c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft;

d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch means comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst whereby said axially acting clutch is engageable by translation of said plunger member;

means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means:

b. a shaft rotatably and translatably joumalled along said axis having a second set of helical splines-and having drive means engageable with said rotatable means;

c. a plunger member received by said splines of said cylinder and being axially translatable'in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and rotary motion clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut towards said drive said nut member from said drive means and f. spring means restraining said axial translation of said nut member on said shaft.

7. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported alongan axis by a housing mountable in proximity to said rotatable means:

a. a cylinder rotatably supported by said housing means and engageable by the axial translation of being axially translatable relative to said drive means in response to rotation of said shaft;

d. axially acting clutch means connecting said rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means.

6. In a starting mechanism for engaging rotatable along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines;

. a shaft rotatably and translatably journalled along said axis having a second set of helical splines and having drive means engageable with said rotatable means;

. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft;

d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst, whereby said axially acting clutch is means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means:

engageable by translation of said plunger member; rotary clutch means connecting said plunger and nut members and axially translatable by said nut a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines;

b. a shaft rotatably and translatably joumalled along said axis having a second set of helical splines and having drive means engageable with said rotatable means;

member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means;

. first spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member; and

g. second spring means for restraining the translation 9. In a starting mechanism for engaging rotatable of said plunger relative to said cylinder. means and drivable by the rotor of a starting motor, 8. In a starting mechanism for engaging rotatable said mechanism supported along an axis by a housing means and drivable by the rotor of a starting motor, tab e in proximity to Said rotatable means: said mechanism supported along an axis by a housing 5 Cylinder l'otatably Supported y Said housing mountable in proximity to said rotatable means: along said a Said y e being rivably 60 a. a cylinder rotatably supported by said housing nected with said Tom! and having a first set of along said axis,-said cylinder being drivably connected with said rotor and having a first set of acting clutch is engageable by translation of said plunger member;

. rotary clutch means connecting said plunger and v splines;

. a shaft rotatably and translatably joumalled along splines; said axis having a second set of splines and having b. a shaft rotatably and translatably joumalled along drive means enga8eable with said rotatable meanS said axis having a second set of splines and having a Plunger recfewed by Sald spllnes of Sam drive means engageable with Said rotatable means; cylinder and being axially translatable in response a plunger member received by said splines of said to Of and cylinder, and a nut member cylinder and being axially translatable in response 15 Sam Set of Splmes Sad Shaft a to rotation of Said cylinder and a nut member being axially translatable relative to said drlve received by said set of splines on said shaft and i resPonse to rotatlonofsald Sham. being axially translatable relative to said drive anally actmg clutch means p q means in response to rotation of said shaft; plunger and nut for causing l plullger d axially acting clutch means connecting Said men'lberlto translate said nut member, said axially plunger and nut members for causing said plunger c fi g g gz T g; 8; member to translate nut member, towar S ag? nu member and ageco nd flange ex acting clutch means comprising a first flange tending radially from said nut member towards tending radially from said plunger member 25 said plunger member, said second flange overtowards Said nut member a d a Second flange lapping a radial portion of said first flange and axitending radially from said nut member towar ally abuttable thereagainst, whereby said axially said plunger member, said second flange over? acting clutch is engageable by translation of said lapping a radial portion of said first flange and axiplunger member; ally abuttable thereagainst, whereby said axially rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means:

. first spring means for engaging said rotary'clutch means when said nut member is translated axially from said drive means;

. first spring means for engaging said rotary clutch 40 seFond Spring means for subsiamiany fiisengagirfg means when said nut member is translated axially Sald r ry clutch means when fotatloll of i from Said drive means; and shaft is above a predetermined speed; and

Second Spring means for disengaging Said rotary h. third spring means for restraining the translation clutch means when notation of Said Shaft is above a of said plunger member relative to said cylinder. predetermined speed.

Claims

1. In a starting mechanism: a. rotatable input means; b. rotatable and translatable output means; c. a plunger member and an output member; d. a first set of helical splines for operatively connecting said input means with said plunger member to rotate and translate said plunger member, and a second set of splines for operatively connecting said output member with said output means to rotate and translate said output means; e. first clutch means for selectively translating one said member with the other said member; f. second clutch means for selectively coupling the rotation of said one member to said other member, said second clutch means translatable with said other member and engageable when said other member translates in one direction relative to said output means and disengageable when said other member translates in the other direction relative to the output means; and g. spring means for engaging said second clutch means when said other member translates in said one direction relative to said output means and for restraining said translation of said other member in said other direction.

2. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism being supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably mounted by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines; b. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having a second set of helical splines and having drive means engageable with said rotatable means; c. a plunger member received by one set of said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member; e. rotary motion clutch means connecting said plunger and nut members and being axially translatable by said nut member relative to said drive means, said rotary clutch means being disengageable by said axial translation of said nut member relative to said drive means and said cylinder and being engageable by the translation of said shaft relative to both said nut member and said cylinder; and f. spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member.

3. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism being supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably mounted by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of splines of a first predetermined pitch; b. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having a second set of helical splines of a second predetermined pitch different from said first pitch and having drive means engageable with said rotatable means; c. a plunger member received by one set of said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member; e. rotary motion clutch means connecting said plunger and nut members and being axially translatable by said nut member relative to said drive means, said rotary clutch means being disengageable by said axial translation of said nut member relative to said drive means and said cylinder and being engageable by the translation of said shaft relative to both said nut member and said cylinder and by said different pitches of said splines; and f. first spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member; and g. second spring means for urging said nut member towards said first spring means from saId drive means.

4. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means; a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines; b. a shaft rotatably and translatably journalled along said axis by one of said housing and cylinder, said shaft having stop means, drive means, and a second set of helical splines therebetween, said drive means engageable with said rotatable means; c. a plunger member received by one set of said splines and being axially translatable in response to rotation of said cylinder, and a nut member received by the other of said splines and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said members for causing said plunger member to translate said nut member; e. rotary motion clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by further axial translation of said nut member than of said drive means and engageable by further axial translation of said shaft than of said nut member; and f. spring means for aiding said plunger member to translate said stop means.

5. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines; b. a shaft rotatably and translatably journalled along said axis having a second set of helical splines and having drive means engageable with said rotatable means; c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch means comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst, whereby said axially acting clutch is engageable by translation of said plunger member; and e. rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means.

6. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines; b. a shaft rotatably and translatably journalled along said axis having a second set of helical splines and having drive means engageable with said rotatable means; c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in respoNse to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch means comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst whereby said axially acting clutch is engageable by translation of said plunger member; e. rotary motion clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut towards said drive means and engageable by the axial translation of said nut member from said drive means and f. spring means restraining said axial translation of said nut member on said shaft.

7. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of helical splines; b. a shaft rotatably and translatably journalled along said axis having a second set of helical splines and having drive means engageable with said rotatable means; c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst, whereby said axially acting clutch is engageable by translation of said plunger member; e. rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means; f. first spring means for engaging said rotary clutch means when said shaft is translated axially with respect to said nut member; and g. second spring means for restraining the translation of said plunger relative to said cylinder.

8. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of splines; b. a shaft rotatably and translatably journalled along said axis having a second set of splines and having drive means engageable with said rotatable means; c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch means comprising a first flange extending radially from said plunger member towArds said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst, whereby said axially acting clutch is engageable by translation of said plunger member; e. rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means; f. first spring means for engaging said rotary clutch means when said nut member is translated axially from said drive means; and g. second spring means for disengaging said rotary clutch means when rotation of said shaft is above a predetermined speed.

9. In a starting mechanism for engaging rotatable means and drivable by the rotor of a starting motor, said mechanism supported along an axis by a housing mountable in proximity to said rotatable means: a. a cylinder rotatably supported by said housing along said axis, said cylinder being drivably connected with said rotor and having a first set of splines; b. a shaft rotatably and translatably journalled along said axis having a second set of splines and having drive means engageable with said rotatable means; c. a plunger member received by said splines of said cylinder and being axially translatable in response to rotation of said cylinder, and a nut member received by said set of splines on said shaft and being axially translatable relative to said drive means in response to rotation of said shaft; d. axially acting clutch means connecting said plunger and nut members for causing said plunger member to translate said nut member, said axially acting clutch means comprising a first flange extending radially from said plunger member towards said nut member and a second flange extending radially from said nut member towards said plunger member, said second flange overlapping a radial portion of said first flange and axially abuttable thereagainst, whereby said axially acting clutch is engageable by translation of said plunger member; e. rotary clutch means connecting said plunger and nut members and axially translatable by said nut member relative to said drive means, said rotary clutch means disengageable by the axial translation of said nut member towards said drive means and engageable by the axial translation of said nut member from said drive means: f. first spring means for engaging said rotary clutch means when said nut member is translated axially from said drive means; g. second spring means for substantially disengaging said rotary clutch means when rotation of said shaft is above a predetermined speed; and h. third spring means for restraining the translation of said plunger member relative to said cylinder.