US1268543A - Safety cranking device for motor-vehicles. - Google Patents

Description

J. P. CARSON.

SAFETY C RANKING DEVICE FOR MOTOR VEHICLES.

APPLICATION FILED JAN.26. [917.

1 ,268Q538 Patented June 4, 1918.

ens earn JOSEPH PRESTON season, or Brent romp, vrnernre, nssrenon To oartsoiv MANUFAC- TUBING CORPORATION, or RICHMOND, VIRGINIA, A conronarron or VIRGINIA.

SAFETY CBANKING Dnvron ron MOTOR-VEHICLES.

raeasae.

Specification of Letters Patent.

Patented June 1, 1918.

Original application filed December 23, 1915, Serial No. 68,385. Divided and this application filed January To all whom it may concern:

Be it known that I, Josnrrr P. CARSON, a citizen of the United States, residing at Richmond, in the county of Chesterfield and State of Virginia, have invented certain new and useful Improvements in Safety Cranking Devices for Motor-Vehicles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in safety cranking devices for explosive engines and is a division of my application, Serial No. 68,385, filed Dec. 23, 1915.

The invention consists in the novel features hereinafter described, reference being had to the accompanying drawing in which I have shown two forms or embodiments of my invention selected by me for purposes of illustration, and the said invention is fully disclosed in the following description and claims.

Referring .to the drawing: Figure 1 is a side view partly in section and partly broken away, of an ordinary crank provided with my improved mechanism for throwing the crank away from the engine shaft, when a back-lire or the like occurs in the engine during'the period when the operator iscranking the engine.

Fig. 2 is a detail showing a face view of a ratchet wheel, which is rigidly secured to the front of a motor vehicle and a pawl member which is loosely mounted on the crank and cooperates with the teeth of said wheel.

Fig. 3 is a perspective View of said pawl member.

Fig. 4 is a diagrammatic view showing the method of disconnecting the ratchet member from the loose pawl, in case of backfire in the engine.

Fig. 5 is a perspective view of the modified ratchet member, for moving the loose pawls over the teeth of the other ratchet member.

In cranking up or starting an explosive engine, by means of the ordinary hand crank, there is great danger of the charge igniting and exploding prematurely, as the piston is approaching the head of the cylinder. When this occurs, the engine, and conse- Seria1 No. 144,696.

backward impetus, and the operators arm or wrist is frequently broken or badly in jured, by the powerful backward blow of the crank. A number .of efforts have been made to produce a safety device, which would be effective for preventing injuries of the character above described, but such devices, as hitherto constructed, have not been successful in operation.

It is. the object of the present invention to obviate thisseriousdefect relating'to the starting of explosive engines, by providing between the engine shaft and hand crank, mechanism including as one of its elements, loose pawls which will automatically throw the crank out of engagement with the engine shaft when a back-fire or the like occurs in the engine cylinder or cylinders.

With the foregoing and other objects in view, which will appear as the nature of my improvement is better understood, the invention resides in the novel combination and arrangement of parts hereinafter described, it being understood that changesin the precise details of the construction disclosed may be made, without departing from the spirit or scope of the invention.

Before proceeding with a more detailed description, it may be stated, that I in the form of my improvement herein shownQI employ a crank shaft and crank for the vehicle, of ordinary construction, special means being employed for throwing out the crank when the engine shaft reverses, whereby accidents will be prevented. The construction and organization of the usual parts of the vehicle, to which my improvement may be applied, do not require alteration or change in any way, since my improvement is practically in the nature of an attachment, adapted for use in connection with almost any type of motor vehicle.

In the embodiment of my invention illustrated in Figs. 1 to e inclusive, the reference numeral 1 designates an ordinary engine crank, having at one end the usual clutch member 2 for engaging a similar clutch on the engine shaft and provided at its opposite end with a hand engaging member (not shown).

Loosely mounted on the crank is a stationary ratchet wheel 3 provided on its rear face with a bracket 4 for rigidly securing the same to the front of a motor vehicle and the small teeth of the wheel 3 and provided on its opposite. side with a large tooth 11, for a purpose hereinafter described.

Another ratchet wheel 12 is rigidly mounted on the crank forward of the pawl member and is provided 011 its rear face with large teeth 13, which cooperate with the large teeth 11 of the pawl member. A coil spring 14 surrounds the crank and bears against the wheel 12 and pawl member 6 for normally maintaining said wheel and pawl member apart and for maintaining the small teeth 10 of the pawl member in con tact with the teeth of the ratchet 3.

A casin 15 incloses the operative portions of the safety mechanism and is secured to ther'atchet wheel 3 by means of screws 16.

In assembling the safety mechanism on a crank, the clutch pin 17 is withdrawn and the clutch removed. Then the casing is slipped onto the crank from the rear thereof, after which the ratchet 12 is placed on the crank and secured by suitable fastening -ls. The spring '14 is then applied and the pawl member 6 and wheel 3 follow and finally the casing is secured to the Wheel 3 by the screws 16 and the bracket 4 secured to the vehicle frame in some suitable manner.

The operation of the device is as follows: When it is desired to crank the engine, the crank 1 is moved longitudinally against the tension of the spring 14, until the clutch 2 engages the clutch of the engine shaft, at which time the teeth 13 of the ratchet wheel 12 will be brought into engagement with the large teeth 11 of the pawl member. Now, when the crank is turned in the usual manner, the pawls 9 will be readily moved over the surface of the teeth 5 by the teeth 13 of the wheel 12. This will be continued until the, motor has started, when the rapid turning of the engine shaft will throw the crank back to its normal osition. During the cranking, however, i there hould be a backfire inthe engine and the engine shaft reversed, the small teeth 10 of the pawls 9, would immediately lock on the teeth 5 of the wheel3, over which the pawls are traveling,

and the teeth 13 of the wheel 12, with which the pawls are in engagement, would be re leased from said pawls and the inclined faces of the adjacent teeth 13, would ride outwardly upon the pawls and automatically force the wheel 12 away from the pawls and the clutch member 2 away from the clutch of the engine shaft, in a manner which will be apparent to those skilled in the art.

In Fig. 5 I have illustrated a modified form of ratchet member 20, which may be used in place of the wheel 12. This member 20 consists of a collar 21, which is secured to the crank by a fastening 22 and carries radial arms 23, which terminate in triangular shaped lugs 24 having at their ends flanges 25, the lugs and flanges forming members for engaging the large teeth 11 of the pawls. This modified device operates in the same manner as'the wheel 12 but is less expensive and of lighter construction.

From the foregoing, it will be seen that I have devised an improved safety cranking device which may be appliedto any ordinary crank without changing the construction of the same, and that by making my pawl member of but two pawls each having a single tooth on its front and rear sides, I obviate the necessity of employing a wheel at this point having teeth extending entirely around both sides of the wheel and the expense and material necessary to make such a wheel.

What I claim and desire to secure by Letters Patent is The combination with an internal combustion engine andits shaft, of a crank provided with a detachable clutch for engaging said shaft, a stationary ratchet member in which said crank turns, teeth provided on the forward face of said ratchet member, a

collar loosely mounted on said crank and provided with radial arms terminating in pawls having small teeth for engagingthe teeth of the ratchet member, and a ratchet wheel rigidly mounted on said crank and having teeth which are adapted to engage said pawls for moving the same over the teeth of the ratchet member when the crank i turned in one direction and ride off of said pawls when the crank is turned in the opposite direction and the pawls lock on said ratchet member.

In testimony whereof Iaflix my signature.

JOSEPH PRESTON CARSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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