US1487686A - Electric starter - Google Patents

Description

March 18 1924.

1,487,686 E. R.- HUNTLEY ELECTRIC STARTER Filed dct. e, 1920 2 Sheets-Sheet 1 INVENTOR.

March 18 1924. 1,487,686

E. R. HUNTLEY ELECTRIC STARTER INVEN A TTORNEY Emeat R 1/ Patented Mar. 18, 1924.

UNITED STATES PATENT OFFICE.

ERNEST R. HUNTLEY, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO INDUSTRIAL RE- SEARCH CORPORATION, OF TOLEDO, OHIO, A CORPORATION OF DELAWARE.

ELECTRIC STARTER.

Application filed October 6, 1920. Serial No. 415,156.

To all whom it may concern:

Be it known that I, Enrtns'r R. HUNTLEY,

a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and 6 State of \Visconsin, have invented certain new 'and useful Improvements in Electric Starters, of which I declare the following to be a full, clear, and exact description.

This invention relates to starting mecha- 10 nism for engines, particularly of that type which are non-starting such as internal combustion engines.

It is customary to employ, as starting means for gas engines, auxiliary motoring devices which serve to give the engine crank shaft the initial impulse prior to the taking up of the ordinary cycle of operation. Especially in connection with automobiles it is common engineering practise to utilize the fly-Wheel of the engine as one of the gear elements and a small electric motor is so placed in relation to this fiy-Wheel as to make connection therewith.

It is one of the objects of this invention to employ a type of mechanism wherein the inion of the motor is moved automatically into engagement with the fly-wheel gear, thereby obviating any use of manual levers or connections.

A second object is to utilize a type of drive connection wherein the disconnection from the fiy-wheel gear is also entirely auto matic, thus disconnection occurring as soon as the engine takes up its own initial impulse.

I have also considered as an object of this invention a type'of drive wherein there are no spring connections such as would be subject to breakage when in use. While springs are ordinarily employed in this drive, they are utilized merely for auxiliary purposes.

Stillanother object considered is the design of a drive wherein the connection, when in operative condition, is positive, there being no opportunity for slippage of the various elements.

An important object also is to associate the various elements of the starter mechanism so as to obtain a gradual absorption of power subsequent to the initial energization of the motor so'that energy from the motor is applied to the engine crank shaft, not by sudden movement, but by a gradual impulse which serves to maintain the omies of manufacture and details of construction will become apparent as I proceed with those forms of the invention illustrated in the accompanying drawings in which,

Figure I is a longitudinal view of the startermechanism partly in section, showing the gears at their normal disconnected position.

Figure II is a cross section through the fluid chamber of tlie" 'tli'ive looking in the direction of the arrows 22 of Figure I.

Figure III is a part section through an electric motor showing a modification of my invention and,

Figure IV is a cross section taken looking in the direction of the arrows H of Figure III.

Referring to Figure I of the drawings, a portion of the fly-wheel of an internal combustion engine is shown at 10 in part section. According to common engineering practise a portion of theperiphery of this wheel is raised as at 11 and gear teeth 12 cut therein of such dimensions as will properly mesh with the motor drive pinion, hereinafter to be described.

Attached to the engine casing 13 in juxtaposition to the engine fly-wheel is an electric motor 14 having an armature 15 and shaft 16. The electric motor is of conventional design, preferably of the series type, but its shaft is extended beyond the end of the motor to an appreciable extent to form a smooth shaft extension 17 upon which the. movable element 18 of the starter is adapted to have sliding and rotary engagement.

, In detail the movable member 18 of the starter consists of a sleeve 19,- one end of $5 which is formed as an element 20 of a jaw clutch which is designed to co-operate with another element 21 of a jaw clutch, formed at the junction of the main motor shaft and its extension. The other end of the sleeve is closed by means of a plug 22 which is screw threaded within the sleeve and is locked in place by means of a washer23 and nut 24. Mounted upon the sleeve adjacent the clutching end is a pinion 25 which is designed to engage with the gear teeth 12 (Si the engine fly-wheel 10, hereinbefore described. In order to facilitate smooth engagement between the pinion and fly-wheel teeth the pinion teeth 26 are preferably chamfered and rounded as indicated at 27.

Serving as means to move the sleeve longi tudinally upon the shaft extension and thereby bringing the pinion-into mesh with the flywheel teeth, I have provided a screw connection between the sleeve and shaft consisting in a pin 28 rigid with the shaft and a slot 29 cut in the sleeve, so functioning, that rotation of the motor shaft carrying the pin therewith causes the sleeve to travel inwardly toward the motor. lVhile I have shown a pin and slot connection here it is obvious that any other equivalent means might be employed such as a screw thread arrangement.

As shown in Figure I of the drawing, when the pinion is in its normal inoperative position a chamber 30 is formed within the outer end of the sleeve between the walls and the end thereof and the end 31 of the shaft extension. This chamber is, of course, variable in its axial dimension dependent upon the position of the sleeve in relation to the shaft. The object of this chamber is to cushion the movement of the sleeve upon'the shaft so as to .prevent sudden transmission of power from the motor to the pinion, such sudden movement being prevented through the fact that the motor shaft moves in the chamber against the air entrapped therein, thereby being hindered in its normal free movement. In such a device it is desirable that the sleeve move freely on the motor shaft until the pinion meshes with the engine fly-wheel as otherwise the pinion will rotate with the motor shaft and therefore will not advance relative therewith. To accomplish this end an aperture 32 is formed in the wall of the chamber at such a distance from the end of the shaft when the sleeve and shaft are in their relative inoperative positions as shown in Figure T, that the pinion and fly-wheel gear become initially enmeshed prior to the closure of the aperture through the movement of the engine shaft. Auxiliary with this first named aperture is a second aperture 33, preferably placed in the plug :22, and associated with this aperture is a one way valve 34 shown in Figure II. This valve consists in a sheet metal disc fixed in the inner end of the plug and cut so as) to have an inwardly protruding tongue member 35 having such flexibility that an outward pressure of air induced by the moving sleeve tends to force the tongue against the aperture 33, thereby hindering the exit of air, while, on the other hand, relative movement: between the sleeve and shaft such as to increase the dimensions of the fluid chamber permits the air to'bedrawn readily into the chamber through the resulting suction.

Surrounding the sleeve I have shown a. coil" spring 36 one end of which has bearing against a washer 23 at the end of the sleeve. The spring is normally under compression and therefore has a constant tendency to force-the sleeve along the shaft in such a direction as to disengage the pinion and engine member.

A casing 37, cylindrical in form and en closing the coil spring and sleeve is mounted on the collar element adjacent the pinion and the washer 23 and is held in place thereupon by means of washers 38 and nut 24.

Considerin 'g the operation of the starter mechanism we may assume that the elements are in the position such as shown in Figure 1. Given an initial rotation of the motor such as to move the pin along its slot the sleeve will be carried axially toward. the motor. The first movement will be -freely. made due to the fact that the egress of air from the fluid chamber is free by means of the aperture. As soon however, as the pinion engages with the fly-wheel and subsequent to such engagement, the end of the shaft extension closes this aperture and con sequently moves against the body of enclosed air within the fluid chamber and, inasmuch as this movement is greatly hindered, through the inability of the enclosed gases to escape except by leaka e around the shaft and through the valve, the sleeve and its accompanying pinion tend to take on the rotation of the motor shaft and an impulse of rotation is consequently imparted to the engine fly-wheel. Due to the fact that there is relative movement between the sleeve and shaft extension, the full effect of the rotary force of the motor is not immediately applied to the engine fly-wheel, but gradually as the pin moves along the slot and the air escapes from the fluid chamber. Finally the pinion becomes fully meshed with the flywheel. and the clutch elements 20 and 21 coengage, whereupon the full power of the motor is applied directly from the motor shaft through the clutch elements to the pinion and engine flywheel.

In the event that when the inion iszmoving axially toward the fly-w eel great the teeth should abut with each other; breakage would very likely result through the wedging of these gear elements together; and while the chamfering of the teeth prevents to a large extent this occurrence it does not totally prevent it.

To take clre of this possibility, the sleeve slot' is slighly widened at that portion of it 39 atwhi h the pinion makes its initial engagement wi the gear so that there is suflicientlost motionbetwe'en the pin and the sleeve at this point to'permit of slight axial movement and consequent rotation of the sleeve to such a degree as to permit the gear teeth to slide by each other and into mesh.

As soon as the engine is started under its own power a sudden impulse is given the motor pinion in the direction of its rotation which causes the sleeve to move outwardly through its pin and slot connection with the shaft. This movement is made.

possible through the fact that the flapper valve of the fluid chamber permits the inflow of air into the same, thus overcoming the slight vacuum produced by the movement of the sleeve. Also the teeth of the clutch elements 20 and 21 are so fashioned as to wedge each other out of contact as clearly shown in Figure I of the drawings. This movement is further aided by means of the spring 36 which, moreover, tendsto carry the sleeve to the limit of its movement away from the engine fly-wheel and maintain it in that position during the period of disuse.

In the modified form of my invention illustrated in Figures III and IV the general principle of operation is similar to that heretofore described, but instead of mounting the pinion on a slidable sleeve, the pinion 50 and its associated clutch element 51 are mounted on a movable drive shaft 52, slidable within a hollow shaft 53 rigidly connected with the armature 54 of the motor 55. The clutch element associated with the pinion is adapted to co-operate with a similar clutch element 56 integral with the hollow shaft so that engagement between these clutch elements is possible when the drive shaft has been driven to the limit of its movement into the hollow motor shaft. When in this latter position the pinion 50 is in full engagement with the fly-wheel gear in a manner similar to that hereinbefore described in reference to; the preferred form.

which is within the hollow shaft has a diameter lesser than the internal diameter of the hollow shaft and the end portion of this drive shaft further removed from the clutch elements is slidably associated with a sleeve 58 fixed within the hollow shaft by means of-pins 59. This sleeve is. slotted as at 60 to receive the pin 61 fixed in the motor shaft. In this modification the spring element 62 is secured around the drive shaft intermediate the sleeve and the shoulder 63 formed on the drive shaft between the portions of different diameters.

As described previously in connection with the other modification, the end of the sleeve and also the hollow shaft is closed by means of a plug 64 which has an aperture 65 controlled by a flapper valve 66 of sheet metal design as indicated in Figure IV of the drawings. The operation of this valve That portion 57 of the drive shaft 52' is indentical in all respects to that previously described.

When the armature of this arrangement is rotated, movement of the slotted sleeve carries the pin and its connected shaft axially in such a direction as to cause enmeshment of the gear and pinion and the clutch element; and subsequent starting of the engine causes retraction of this movement. In this modified arrangement the valve aperture is the only one employed, the leakage of the air around the drive shaft and through the valve permitting the requisite initial freemovement.

I am aware that these particular embodiments of my invention as described and illustrated in the accompanying drawings are susceptible of considerable variation without departing from the spirit of the inventionand therefore I desire to claim the same broadly as well as specifically as indicated by the appended claims.

I claim as my invention:

1. In a starting mechanism for gas engines, the combination of a motor having a main shaft; an extension shaft having a diameter less than that of the main shaft; an element of a jaw clutch formed at the junction of said shafts; a pin on the extension shaft; a sleeve on the extension shaft formed with an advancing slot therein, said slot being adapted to have sliding engagementwith the pin; a clutch element on the end of thesleeve adjacent the first named clutch element and adapted to engage therewith; a gear'wheel secured to the sleeve adjacent the sleeve clutch element; a plug at the. end of the sleeve opposite to the clutch end, said plug having an aperture therein; a valve for the aperture fittedto permit free passage of air into the sleeve interior and prevent free passage of air from within the sleeve; a coil spring surrounding said sleeve and having a bearing on the pin and a portion of the sleeve whereby the sleeve is urged along the extension shaft in a direction to open the jaw clutch; and a tubular casing fixed to and enclosing said spring and sleeve.

2. In a starting mechanism for gas engines. the combination of a motor; a shaft for the motor having an axial extension; an element of a jaw clutch formed at the junction of the shaft and extension; a sleeve on the extension having the co-operating element of a jaw clutch at one end thereof adjacent the first named clutch element; a pinion fixed to the sleeve adjacent the sleeve clutch element; connecting means between the extension and sleeve operative to move the clutch elements into mutual engagement; and means tending to hold the clutch elements out of engagement; said sleeve and shaft extension co-operating to form a power absorbing unit whereby connection of the clutch elements is madegradually.

3. In a drive mechanism, the combination of a motor having a shaft; a shaft extension integral with the shaft having a diameter less than that of the shaft; an element of a jaw clutch formed at the junction of the shaft and extension; a sleeve on the shaft extension having limited rotary and axial movement relative to the shaft, said sleeve normally extending beyond the end of the extension; a plug in the end of the sleeve adjacent the extension forming with the sleeve and extension a lunger chamber for the extension; a second clutch element on the sleeve end adjacent the shaft clutch element; and a drive wheel secured to the sleeve adjacent the sleeve clutch element.

4:. A starter mechanism for gas engines having in combination a motor shaft; an element of a jaw clutch at one end of the shaft; a shaft extension integral with and coaxially extended from said shaft; and a movable element mounted on said extension for both rotary and axial movement, said element comprising a sleeve closed at one end and formed with an element of a jaw clutch at its other end adapted to cooperate with and engage said first named clutch element; a pinion secured to the sleeve adjacent the sleeve clutch element; means coacting with said extension adapted to give rotary and axial motion to the sleeve; and a chamber formed between the walls of the sleeve, the closed sleeve end and the shaft extension end, said chamber being effective to absorb energy when the speed of shaft rotation is accelerated.

5. In a starter mechanism for engines, the combination of a motor having an extended shaft; a sleeve having one end closed mounted for limited slidable movement on the shaft; means associated with said sleeve and shaft for effecting a positive driving engagement thereinbetween; a drive wheel mounted on said sleeve; screw elements interconnected between the sleeve and shaft for effecting axial and rotary movement of the sleeve on the shaft; a fluid chamber formed in the sleeve interior between the sleeve and shaft ends; an aperture in the wall of the chamber; a valve cooperating with said aperture and being effective to hinder the assa-ge of fluid outwardly from the chamber interior.

6. In a starter mechanism for engines, the combination of a motor having an extended shaft; a sleeve having one end closed mounted for limited slidable movement on the shaft; means associated with said sleeve and shaft for effecting a positive driving engagement thereinbetween; .a drive wheel mounted on said sleeve; screw elements interconnected between the sleeve and shaft for effecting axial and rotary movement of the sleeve on the shaft; a variable volume fluid chamber formed in the sleeve interior between the sleeve and shaft ends, said volume being varied by the relative movement of the shaft end; a plurality of apertures in the' wall of said chamber; a valve co-operating with one of said apertures and being effective to permit free passage of fluid into said chamber and to hinder the passage of fluid from within the chamber outwardly; and resilient means normally tending to urge said sleeve along said shaft in a. direction effective for breaking said positive driving engagement.

7. An engine starter comprising a power shaft; a sleeve having one end closed mounted thereon for both rotary and axial movement relative thereto; co-operating clutch elements ecured to said sleeve and shaft for establishing a positive driving connection thereinbetween; a drive wheel mounted on the sleeve; screw elements intermeshed between the sleeve and shaft effective for causing axial movement of the sleeve on the shaft and interengagement of the cooperative clutch elements; a variable volume fluid chamber formed at the closed end of the sleeve and limited by the shaft end; an aperture in the wall of the chamber; a one way valve associated with said aperture adapted to close said aperture when the fluid chamber is diminishing in volume; a second aperture in the chamber, said second aperture being unrestricted and being adapted to be closed by the movement of the shaft end as it moves to vary the volume of the fluid chamber; and resilient means tending to maintain said fluid chamber at its maximum expanded position.

8. A starter for gas engines comprising a motor shaft; 3, drive member movable axially relative to the shaft; interengageable clutch elements on said member and shaft; a drive wheel mounted on said member; means interconnecting the drive member and shaft operable for moving the clutch elements into engagement; a shock absorber including a fluid chamber associated with the drive member and shaft; and resilient means tending to maintain said clutch elements out of interengagement.

9. In a starting mechanism for engines the combination of a motor having a nonslidable shaft; a clutch element fixed to said shaft; a movable member slidably associated with said shaft; a clutch element secured to said member and adapted to have operative engagement with said non-slidable clutch element; a drive wheel mounted on said ember; screw elements connecting said shaft and movable member whereby movement of the clutch elements into and out of engagement is obtained; and resilient means normally urging the clutch elements means interconnecting the shaft and sleeve out of interengagement. wherebyaxial movement is imparted to the 10 10. In a drive mechanism, the combinasleeve, and means operative to retard movetion of a shaft, a clutch member fixed therement of the sleeve on the shaft.

5 to, a sleeve movable on the shaft, a second In testimony whereof, I aflix my signaclutch member secured to said sleeve and ture. adapted to cooperate with said shaft clutch member, a gear secured to the sleeve, and ERNEST R. HUNTLEY.

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