US 2926648 A
Description (OCR text may contain errors)
March 1, 1960 L. J. HAMMAN ENGINE STARTER 4 Sheets-Sheet 1 Filed Feb. 11. 1957 mvsmon [J45 d. HAM/1AM ATTORNEY March 1, 1960 L. J. HAMMAN ENGINE STARTER 4 Sheets-Sheet 2 Filed Feb. 11, 1957 INVENTOR V Ans J HAMMAA/ BY\ LWMMM' ATTORNEY March 1, 1960 L. J. HAMMAN ENGINE STARTER Filed Feb. 11, 1957 4 Sheets-Sheet 3 I INVENTOR .6 v.45 HflMM/I/V ATTORNEY March 1, 1960 L. J. HAMMAN 2,926,648
ENGINE STARTER 4 Sheets-Sheet 4 Filed Feb. 11, 1957 INVENTOR Z n: J A/J/V/VA/V ATTORNEY United States Patent ENGINE STARTER Lyle I. Hamman, Eaton Rapids,-Mich., assignor to Eaton Stamping Company, a corporation of Michigan Application February 11, 1957, Serial No. 639,507
9 Claims. (Cl. 123-179) The present invention relates to improvements in recoil engine starter of the type having a rope "wound upon a pulley by a spring and when the rope is pulled a clutch mechanism attached to the pulley engages a part attached to the engine for rotating the engine to start it. When the rope is released the spring will rewind the rope upon the pulley.
It is an object of the invention to provide a simple, inexpensive and readily serviced starter. To this end my improved starter has been designed with a minimum number of component parts, all of which may be readily assembled by unskilled persons. It trouble developsin use, such as rope breakage, the operator may easily disassemble the starter to replace the rope or make other necessary repairs or replacements.
Another object of the invention is to provide a starter which employs only a single clutch dog and which makes it possible to mount the starter upon an engine without the necessity of maintaining exact concentricity between the engine and the starter.
Another object is to provide a starter of the type described in which retraction of the rope and clutch dog is performed by a single spring.
Another object is to provide an improved starter of the type described in which the clutch dog is carried directly by the pulley and engages directly with the starter hub attached to the engine.
A further object is to provide a clutch dog and brake structure which permits a recess for the bolt head or nut attaching the starting hub to the engine and thus reduce the overall height of the starter.
These and other objects and advantages will more fully appear from the following specification and appended claims.
In the drawings,
Fig. 1 is a cross-sectional view of the starter assembly taken on line 1-4 of Fig. 2, the engine being shown in dotted outline,
Fig. 2 is a top view of the starter housing and assembly shown in Fig. 1,
Fig. 3 is a bottom view of the starter housing and assembly shown in Fig. 2 showing the clutch dog retracted and rope fully recoiled,
Fig. 4 is a view similar to Fig. 3 showing the clutch dog projected by a pull upon the rope,
Fig. 5 is a top view of the retainer cup for the clutch dog removed from the assembly of Fig. I,
Fig. 6 is a side-elevational view of Fig. 5,
Fig. 7 is a side view of the starter brake-removed from the assembly of Fig. 1,
Fig. 8 is a plan view of the starter pulley assembly as viewed from the side'to which the spring is attached,
Fig. 9 is a plan view of the starter pulley assembly as viewed from the side to which the retainer cup for the clutch dog is attached, the clutch dog being shown in position,
Fig. 10 is across-sectional view taken on line X-X 2 of Fig. 8 showing the manner in which the end of the rope is anchored, and I Fig. 11 is a view taken on line Xi-- Xi of Fig. 1 showing theclutch dog projecting to engage the starter hub serrations.
Referring to the illustrated form of the invention, the starter assembly comprises a die cast housing 10 having an inserted pin 12 upon which the pulley assembly 14 is rotatably supported. Recoil spring 16 is carried within the cylindrical recess 18 of the housing 10. The starter hub 20, attached to the engine 22 by thebolt and nut 24, has serrations 26 defined in the cylindrical flange 28 in opposed relation to the clutch dog 30 guided and retained by the retainer cup 32. A brake 34, attached to the .pin 12 by the screw 36, places a drag upon the cup 32 to control the movement of the cup 32 relative to the pulley 14 and thus controls the operation of the dog 30.
The pulley assembly 14 preferably comprises a die cast pulley portion 38 and a stamped sheet metal sheave portion 40. Portion 38 has two diametrically opposed arcuate bosses upon which the retainer cup 32 is mounted and supported for limited relative rotation about the axis of the pin 12 upon the pulley assembly 14. This limited relative rotation is provided by arcuate slots 42 in which complementary arcuate portions of the bosses 44 and 45 engage; screws 43 received in the bosses 44 and 45 engage the ends of the slots 42 to act as stops and also function to hold the retainer cup 32 in position on the bosses 44 and 45 by overlapping the slot defining portions of the cup 32. The drag action of the brake 34 upon the retainer cup 32 is obtained by the provision of an inner cylindrical flange 46 upon the cup 32 with which the resilient fingers 48 of the brake 34 engage.
To conveniently anchor the inner end of the rope 50 to the pulley assembly 14, the pulley portion 38 has two integral ribs 52 across which the rope end is supported at the time the sheave 40 is assembled in position. On the inner surface of the sheave 40 are similar formed ribs 54 is slightly offset relation to the ribs 52 but located to engage the side of the rope opposed to that engaged by the ribs 52. When the sheave 40 is then attached to the pulley portion 38 by the screws 56, the rope end will be firmly anchored in the pulley assembly 14- 7 As shown in Fig. 11 the dog30 takes the form of a length of flat metal stock having one end formed into a semi-cylindrical portion 58 and received for swivel movement in the socket 60 in the boss 45. The free end 62 of the dog 30 is guided within a slot 63 in the outer flange 64 of the cup 32. Upon relative rotational movement between the boss 45 and the cup 32, the relationship between the dog 30 and the slot 63 will cause the dog 30 to be either projected or retracted within the slot 63 depending upon the direction of relative rotation of the boss 45. When the dog is projected its outer end 66 will engage the serrations 26 of the starter hub 20 attached to the engine 22 to crank the engine in a well known manner. Rotation of the pulley assembly 14 in a recoiling direction will retract the dog 30 in the slot 63-due to the drag action of the brake 34 on the cup 32 which momentarily holds the cup 32 stationary as the rotation of the boss 45 withdraws the dog 30 from its projected position.
To avoid any possibility of the cup 32 shifting from one position to another due to vibration of the engine, a light spring 68 is shown attached to the cup 32 to hold the cup in a dog retracting position. It will be understood that the spring 68 is too light to overcome the function of the brake 34.
One end of the spring 16 is attached to the housing 10 and the opposite end is attached to the boss 70 on the pulley assembly 14 and embraces the same within the V recess 18. To permit the spring 16 to be placed under necessary tension to rewind the rope 50, a slot 72 is provided in the flange 74,,of the pulley assembly to receive the end of the rope coiled upon the pulley assembly and provide the necessary clearance between the housing and the flange 74 to enable the pulley assembly to be rotated to wind up the spring 16 prior to the end of the rope 50 being located within its fixed bushing in the housing 10.
Disregarding the optional tension spring 68, it will be seen that the recoil spring 16 performs the entire retraction operation. When the engine starts the action on the 'dog 30 will force the dog 30 against the portion of the cup 32 defining the slot 63 to move the cup 32 relative to the boss 45 to retract the dog 36'. If the engine does not start to initiate this retraction of the dog 30, the combined function'of the brake 34 and spring 16 will, when the rope 50' is released to the action of the recoil spring 16.
By having the dog 30 directly carried on the boss 45 of the pulley assembly 14, the operative connection between the pulley and the starter cup on the engine is solely confined to the dog 30. In practice a single dog 30 has been found to be adequate although more than one dog 30 may be used by merely duplicating the structure disclosed. The design disclosed is characterized by the fact that it is only necessary for performance to hold the concentricity of the starter hub 20 and pulley assembly 14 within limits that may be readily met under ordinary manufacturing practices.
A low overall height between the starter hub 20 and the housing 10 has been made possible by the design of the cup'32 and brake 34 providing clearance for the bolt and nut attaching the hub 20 to the engine 22.
Having thus described my invention what I claim as new and desire to cover by Letters Patent is:
1. In an engine cranking device operated by withdrawing a flexible member wound upon a pulley, the member being rewound by a spring and the rotation of the pulley being imparted to the engine through a clutch mechanism including a dog, the combination with pulley supporting structure, a pulley and a dog pivoted upon said pulley, of a retainer for actuating said dog to project and retract the same in the function of the clutch mechanism, said retainer being of annular form of U-shaped cross-section with inner and outer flanges, a mounting structure for the pivotal connection of said dog located on one side of said pulley in off set relation to the axis of rotation of said pulle a guide slot in said outer flange, said mounting structure being located within said outer and inner flanges, said dog being received in said slot and having relative end-wise movement therein, means attaching said retainer upon said pulley side for rotation of said pulley as a unit as well as for limited relative rotation on said pulley side about said axis, brake structure for imparting a frictional drag upon said retainer, said brake structure being attached to said pulley supporting structure and held against rotation with said pulley and having frictional engagement with said inner flange, and means on said side having a lost motion pin and slot connection with a portion of said retainer to drive said retainer as a unit with said pulley against the drag of said brake upon rotation of said pulley in either direction, said brake structure holding said retainer against rotation with said pulley upon initial rotation of said pulley in either direction within the arcuate extent of said lost motion connection whereby the location of saidslot to the pivotal mounting of said dog is altered to provide endwise projection and retraction of said dog relative to said slot.
2. In the combination of claim 1 wherein said brake has circumferential engagement with said inner flange to equally distribute and: apply the drag of said brake relative to the direction of rotation of said pulley.
3. In the combination set forth in claim 2 wherein said pin and slot connection is defined by said retainer having arcuate slots in the radial side thereof disposed between said flanges, and screws extending through said slots and engaged in said mounting structure.
4. In an engine cranking device operated by withdrawing a flexible member woun'd' upon a pulley, the member being rewound by a spring and the rotation of the pulley being imparted to the engine through a clutch mechanism including a dog, the combination with pulley sup porting structure, a pulley and a dog pivoted thereon, of
means for rocking said dog into and out of engine cranking position, said means comprising a dog actuator mounted upon one side of said pulley, means supporting said actuator for limited relative rotation on said pulley side about the axis of rotation of said pulley, said last supporting means including a lost motion drive connection between said actuator and said pulley, said actuator having an annular outer axially extending flange, means pivotally supporting said dog on said pulley between said actuator and the axis of rotation of said pulley, a guide and cam portion in the form of a slot formed in said flange of said actuator in which said dog is guided and rocked about its pivot and brake means fixed upon said pulley supporting structure and engaging with said actu ator to retard the movement of said actuator to effect relative movement between said actuator and said pulley upon initial movement of said pulley in either direction.
5. In an engine cranking device as defined in claim 4 said actuator being in the form of an annular member of U-shaped cross-section and having an inner flange as well as said outer flange, said brake being in the form of circumferentially spaced resilient fingers engaging with said inner flange.
6. In an engine cranking device, the combination with a spring re-coil winder for the starting rope, a pulley and a clutch mechanism including a dog pivoted upon said pulley, of dog actuator structure in the form of inner and outer annular flange portions connected by a radial web portion, means projecting from a side of said pulley upon which said dog actuator is supported for limited relative movement on said pulley, a pin and slot lost motion connection between said web portion and said projecting means, said flanges being disposed upon opposite sides of said projecting means, a brake ring concentric .with the axis of rotation of said pulley and disposed within said projecting means and engaging with said inner flange, said dog being pivoted on said projecting means with its pivotal axis being located between said flanges, said dog projecting through an opening in said outer flange and being rocked about its pivotal axis by relative rotation between said actuator and pulley.
7. In a engine cranking device of the type described, a separable two part pulley upon which a rope is to be wound and unwound, hub structure on one of said pulley parts upon which the other of said pulley part is piloted, opposed ribs defined upon said parts disposed in staggered relation to each other, a rope to be wound upon said pulley and having its inner end disposed between said opposed ribs, and removable means for. attaching said parts together and simultaneously clamping said rope end between said ribs.
8. In an engine cranking device, in combination with a fixed structure and a recoil spring, of a pulley to which said spring is attached at one end to one side of the pulley with the other end of said spring attached to said fixed structure, dog mounting means formed on the other side of said pulley integral therewith, a dog pivotally supactuator and said pulley.
' 9. In an engine cranking device, in combination, a pulley, a support on one side of said pulley concentric with the axis of rotation of said pulley,'an annular actuator nested on said support and rotatable relative to said pulley in said support, a clutch dog pivotally carried upo'n said support, said actuator having an annular flange having a slot defined therein through which said dog is projected and retracted upon relative movement between said actuator and said pulley, means defining a lost motion connection between said support and said actuator, and an annular brake concentric with said axis and nesting with a portion of said actuator and frictionally engaging therewith.
References Cited in the file of this patent UNITED STATES PATENTS 1,272,944 Green July 16, 1918 2,460,420 Kincannon Feb. 1, 1949 2,530,623 Martin Nov. 21, 1950 2,564,787 Mack Aug. 21, 1951 2,592,639 Armstrong et a1 Apr. 15, 1952 2,848,987 Morden Aug. 26, 1958