US3716039A

US3716039A - Hand-starting auxiliary device for internal combustion engines

Info

Publication number: US3716039A
Application number: US00197393A
Authority: US
Inventors: D Perry
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-11-10
Filing date: 1971-11-10
Publication date: 1973-02-13
Anticipated expiration: 1990-02-13

Abstract

An auxiliary device that is attached to the crankshaft of a hand-started internal combustion engine, comprising a beehiveshaped body having a base, adjacent to the engine, and a spiral groove therearound that terminates in a notch at the apex thereof within four full turns. The initial groove at the base comprises a double groove. Substantial inward progression of the groove toward the axis of the body approximately coincides with the initiation of firing by the engine, whereby high power input is sustained until firing commences, and rotational speed is increased thereafter.

Description

United States Patent Perry 1 Feb. 13, 1973 [54] HAND-STARTING AUXILIARY DEVICE 1,622,289 3/1927 Nelson ..l23/185 A 2,286,419 6/1942 Krenzke... ..123/185 BA ggg g g COMBUSTION 2;323,535 7/1943 Gorden ..123/185 BA 2,530,623 11/1950 Martin ..123/185 BA Inventor: Donald R. Perry, Manderley Place,

Salem, W. Va. 26426 Filed: Nov. 10, 1971 Appl. No.: 197,393

Related US. Application Data Continuation-impart of Ser. No. 31,620, April 27, 1970, abandoned.

US. Cl. ..l23/185 A, 74/6 Int. Cl ..F02n 3/02 185 BA, 123/185 BB, 185 D, 179 SE, 179 P; 74/6,506

References Cited UNITED STATES PATENTS v 6/1916 Davenport ..l23/l85 A UX Primary ExaminerAl Lawrence Smith Att0rneyDonal E. McCarthy et a1.

[57] ABSTRACT An auxiliary device that is attached to the crankshaft of a hand-started internal combustion engine, comprising a beehive-shaped body having a base, adjacent to the engine, and a spiral groove therearound that terminates in a notch at the apex thereof within four fullturns. The initial groove at the base comprises a double groove. Substantial inward progression of the groove toward the axis of the body approximately coincides with the initiation of firing by the engine, whereby high power input is sustained until firing commences, and rotational speed is increased thereafter.

5 Claims, 4 Drawing Figures HAND-STARTING AUXILIARY DEVICE FOR INTERNAL COMBUSTION ENGINES This application is a continuation-in-part of my prior application Serial No. 31,620, filed April 27 1970, and now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to devices for hand-started internal combustion engines which are typicallyused for powering small tractors, cultivators, mowers, boats, snowmobiles, and the like, and particularly relates to devices, which are selectively attached to relatively small internal combustion engines for use with a pull rope in hand starting thereof.

2. Description of the Prior Art Such engines, whether two-stroke cycle or fourstroke cycle, require maximum sustained power input for overcoming resistance created by compression and friction of engine parts during initial phase of the starting process. A plurality of revolutions, generally two or three, are required before firing begins and the engine is able to contribute its own power toward its rotation. It is at this point that the starting device should impart decreased power input and increased rotational velocity.

Devices in the prior art, such as US. Pat. No. 1,622,289 of Victor B. Nelson, have combined high initial powervinput with immediately decreasing power input and rapidly increasing rotational velocity. The Nelson device, designed nearly 50 years ago, was intended for a small portable engine of the kind used for propelling canoes, rowboats and the like when such engines were slow in rpm and low in brake horsepower so that initial firing could occur earlier than in the relatively high-compression, high speed, and high brakehorsepower engines of the present day when 100 H.P. outboard engines are becoming common on small boats. For a frusto-conical Nelson body having a base diameter of 6.2 inches as measured from center to center of the pull rope therealong, the cumulative circumference, C, of the spiral groove, as measured by the length of wound pull rope thereupon, is given in inches in terms of turns, T, through five full turns, as: C= 16.4 70.84

Specifically, when the bell-shaped Nelson body has made one complete revolution, the pull rope has moved so far inwardly toward the axis of the body that its leverage has significantly decreased, with corresponding decrease in available power input to the engine. Because firing rarely begins within a single turn,

the loss in leverage seriously impairs the available power input before firing begins and also attempts to initiate relatively rapid rotationprematurely, particularly when. the device is used for attempting to start larger engines having relatively high brake horsepower ratings and compression ratios. I

SUMMARY OF THE INVENTION It is an additional object of this invention to provide means for attaching the accessory starting device of this invention to the crankshaft and over the pulley hub of an internal combustion engine.

DESCRIPTION OF THE INVENTION The manual starting device for an internal combustion engine of this invention comprises a beehiveshaped body which is coaxially attached to the crankshaft of the engine and has a spiral groove of sufficient width to accommodate a pull rope. This groove has a double widthalong an initial portion of its length at the base of the body and terminates in a pull notch at the apex thereof within four full turns.

For a body having a base diameter of 6.2 inches as measured from center to center of the pull rope therealong, the cumulative circumference, C, of the spiral groove, as measured by the length of wound pull The invention further comprises a means for simply and rapidly attaching the beehive-shaped body onto the crankshaft of an engine. This attaching feature comprises a central well which is open on the apex end of the body and an annular slot that is open on the base side of the body, adjacent to the engine, the base of the well being substantially flush with the base of the body and the sides of thewell forming the sides of the slot. A central opening in the base, and therefore also in the well, fits the crankshaft whereby there is coaxial fitting I thereto. The annular slot fits over the hub of the pulley of a popular existing type of internal combustion engine when the beehive-shaped body is superimposed.

over the hub. A dowel in the annular slot engages the notch in the pulley to prevent relative rotation, By fastening the nut to the crankshaft, the attaching operation is completed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of an internal combustion engine having the manual starting device of this inven- 7 DESCRIPTION OF THE PREFERRED EMBODIMENT The beehive-shaped body 40, as shown in the drawings, comprises the base 42, the apex 41, the annular slot 43 which opens toward the base 42, the well 44 having a bottom which substantially coincides with the base 42 and a circular side 45 which also forms the inner side of the annular slot 43, and the central opening 46 in the bottom of the well. Covering the outer side of the beehive-shaped body 40 is a spiral groove, consisting of the single grooves 52 leading from the notch 51 and leading to the base groove 53 which is adjacent to the base 42 of the body and has the double groove 54 as the initial portion thereof between a convenient lead-off point 58 and the doubled lead-off point 59 which is in radial alignment with the notch 51.

As shown in FIG. 1, an engine 20, such as is used in a typical lawn mower, has a throttle 21 and a pulley 22 which is coaxially attached to a crankshaft 23 and secured thereto with a nut 26. The pulley 22 has a hub 24 in which is a keyway 27 at the lip thereof. As shown particularly in FIG. 4, the annular slot 43 fits over the hub 24 of the pulley 22 so that when the dowel 47 is aligned with the keyway 27, the body 40 is nonrotatably adjacent to the engine 20, the crankshaft 23 being, of course, coaxially inserted into the opening 46. When the nut 26 is secured onto the crankshaft 23, the body 40 is rigidly attached to the engine 20.

A pull rope 56, having a handle 57, is attached at its terminus to the notch 51 in the body 40 and is wound along the spiral grooves 52 and then into the base groove 53 for one full turn to the convenient lead-off point 58. Additional power, however, can be obtained by winding an additional portion along the short double-width groove 54 to the doubled lead-off point 59 so that four full turns of rope are available.

After the pull rope 56 has been pulled, perpendicularly to the axis of the crankshaft 23, through two to three turns, firing of the engine by combustion of the mixture in the cylinders usually begins. At this point, the single grooves 52 of the beehive-shaped body of this invention rapidly progress inwardly toward the notch 51 at the apex 41. Rotational velocity of the engine, as engine power augments hand-starting power,

normally increases at this point, and less pulling power is needed. Thereafter, the pull rope simply maintains a diminishing but steady power input and steadily increasing rotational velocity for the final one or two turns. As a result, the powerful, high-compression, larger engines of the present day are readily started.

What has been described hereinbefore may be modified by those skilled in the art, but what is intended to be protected as coming within the scope of the invention is defined in the following claims.

What is claimed is:

l. A manual starting device for an internal combustion engine attached to the crankshaft of said engine, comprising a beehive-shaped body having a spiral groove of sufficient width to accomodate a pull rope, said groove having an initial double width along a portion of its length at the base of said body and terminating in a pull notch at the apex thereof within four full turns.

2. The device of claim 1 wherein the diameter of said base is 6.2 inches and the cumulative circumference, 6, of said spiral groove, as measured by the length of wound pull rope thereupon, is given in inches per turn,

as c= 20.0 1

3. The device of claim Lwherein said engine has a pulley thereon and said body is attached to said crankshaft by superimposing said body over the hub of said pulley.

4. The device of claim 3 wherein said body has a central well which is open on the apex end of said body and an annular slot that is open on the base side of said body,-said well having a base that is flush with said base and sides which form the sides of said slot, said base having a central opening that fits said crankshaft.

5. The device of claim 4 wherein a dowel at the base of said slot projects toward said engine and mates with a keyway in said hub to prevent said body from rotating independently of said hub.

Claims

1. A manual starting device for an internal combustion engine attached to the crankshaft of said engine, comprising a beehiveshaped body having a spiral groove of sufficient width to accomodate a pull rope, said groove having an initial double width along a portion of its length at the base of said body and terminating in a pull notch at the apex thereof within four full turns.

1. A manual starting device for an internal combustion engine attached to the crankshaft of said engine, comprising a beehive-shaped body having a spiral groove of sufficient width to accomodate a pull rope, said groove having an initial double width along a portion of its length at the base of said body and terminating in a pull notch at the apex thereof within four full turns.

2. The device of claim 1 wherein the diameter of said base is 6.2 inches and the cumulative circumference, C, of said spiral groove, as measured by the length of wound pull rope thereupon, is given in inches per turn, T, as: C 20.0 T0.90

3. The device of claim 1 wherein said engine has a pulley thereon and said body is attached to said crankshaft by superimposing said body over the hub of said pulley.

4. The device of claim 3 wherein said body has a central well which is open on the apex end of said body and an annular slot that is open on the base side of said body, said well having a base that is flush with said base and sides which form the sides of said slot, said base having a central opening that fits said crankshaft.