US2551987A - Gas hammer starter - Google Patents

Description

May 8, 1951 c. s. WEYANDT GAS HAMMER STARTER 3 Sheets-Sheet 1 Filed Dec. 9, 1946 Kw m4 my W 5 L M C. M

y 1951 c. s. WEQYANDT 2,551,987

' GAS HAMMER STARTER Filed D60. 9, 1946 3 Sheets-Sheet 2 INVENTOR. 01m. 5. WHA/VOT QMM 096W y 1951 c. s. WEYANDT 2,551,987

GAS HAMMER STARTER Filed Dec. 9, 1946 3 Sheets-Sheet 3 IN V EN TOR. C404 5. WE 2W0r HIS 4 7' TOR/Vi 7.

Patented May 8, 1951 UNITED ATENT O FF ICE GAS- HAMMER STARTER .GarLS. Weyandt, Homer-Qity',.Pa.

'- Application-December 9, 1946,'Serial-No. 714,985

1 Claim. '11 1 1 This-inventionrelates-generally.itoiportable. in- -ternalcombustion percussion. .toolszzorportable gasoline hammers: and more. particularly;to.-ap Y paratus =for starting tools of this character.

invention is av continuation'inpartof ap one hand-while settingicand windingv a;,knotted starter rope .aroundirthe. notched :Starter pulley to spin the-crankshaft. ;As with. goutboardrmm .tors' these ":two :-.cycle..:engines-; may require two or 1 more crankingsr: before :they. start ;,operating. .An outboard motor attachedito, fitbOEtthdOBS not present a difiicult'probl-emgas both :hands-are-free to andi-wind-theistarter rope and hold-the 1 .motor .when;.thej starter -r ope:.is pulled. eI-Iowever a-igasoline. hammergislheldsin. a vertical-position 1 ito'zstart it andgthewlefthand must-{be employed zato steady-.1andholdv the hammer directly :above mthe pullgonzthe starter ropeto preventthe .ham- :mer from turning and: twisting .out :ofe. the-operators grasp andefa-rllingtothe .ground,-. org-to prevent the. starter rope. fromjouling. These .problems are-solved by .the application of aerecoily starter to a asoline hammer, and. the principalobiect: ,of this invention. is.-;-th .provision .of a recoil-starter for agasolinerhammer,toJaci1i-. -;-tate.starting'thesame. Another, object .is: the:provision-:01?- a =:-re.coi1

;: starter that permits the crankshaft of rthe gaso- :1ine.. hammer-. to be :steppedraroundior charging --.t;he cylindenwith tuelspz eparatory .rto applyingithestart nepull.

::.A1l-,Qth6l.i0bj6.0b is the-provision-of anninternal qcombustion percussion-hand,tool having a: guid- ;.inghandledisposed in substantial verticalaligni ment with a-pulLcord :starting. mechanism which j permits theptool to.1be';.-steadied withtonet-hand "while .the; operator. actuates theapu1l-cord with the other handand thus-.prevents1 the .tool .from being twisted from the grasp of the operator.

;:An0.ther. objects is athetprovision iof an internal; ..-:combustion percussion tool having artiming-pis- :t0n.-;.-and. air-working.- piston. and; arranged -;to be {star-ted. byrthegoperation of the. timih piston.

Qther..objects:,;and advantages appeara-inrthe .=-:i0I1QllV:iJ1g descripticniand claim.

A practical embodiment, illustrating the :principles of this-.inventionis shown, in theaaccompanying drawings wherein:

Fig. 1 is a .viewnin side elevation showing the recoil starter on the gasoline hammer.

"Fig. 2: is a fragmentary-frontview of theagasoline hammer with. the-recoil starter shown inisection.

' Fig. 3 isan enlargediview; in side elevationtof the recoil starter with a' portion.-of...the cover and bracket broken away.

Fig. 4 is atop plan-view of "Fig; 3"withthe cover removed.

Fig. 5 is. a sectional view oftheistarterzpulley and. shaft takenalong the line 5+5iof'Fig. 4 .with

the pawl and pawl. spring superimposed thereon.

Fig. Sis a fragmentary sectional viewr'ofthe gasoline hammer with themc'difi'ed formof re- 'coilstarter.

Fig. '7 is an end view of theistructure' shown in -Fig'. 6 withparts broken away.

Fig. 8' is alongitudinal'view in section'taken on the line- B- -Ki of Fig. 1.

'Referring'first to Figs. 1 and 2 the gasoline hammer comprises the cylinder casting-l0 in which a timing; piston and a percussive working piston operate. The lower end of the cylinder-I0 has the nose casting H secured thereto -'Which is arranged to receive the-bit or tool 12.

-split crankcase l3 bolted thereto which houses the crankshaft 14- rotatably-supported-in the The upper end' of'the cylindercasting-ln has the the -left-tend has therecoil starter -mechanism mounted thereon.

The timing piston I is connectedtothe-crankshaft I4'by means of the "connecting rod 3 shown 1 in Fig: 8. qThetiming piston controlsthe combustion of fuel in the combustion chamber 'between'the twopistons which .drives' the working piston 2 in a working direction to strike the bit l2. .When the working piston uncoversthe port 4 exhaust gas is conducted'throughthepassage 5 and the valve 6. to the underside of the working piston where the pressure of'the exhaust gas is effective. in returning the working piston. The

.-valve Bis. actuated by the rod 1 attached to the fuel. throttle beam 8 which in turn. is actuated .bytheiuelthrottle lever 59 on .the handle 58.

:4 Thacrank. shaft .i Lhas the collar 11. and the hubbed ratchet gear l8 pinned thereon in spaced relation as shown in Fig. 5. The bushed starter pulley 20 is journaled on the crankshaft between the collar l1 and the ratchet gear l8 and would be free to rotate thereon if it were not for the helical spring 2|, one end of which is looped around the post 22 in the pulley 20 and the other end is secured by the set screw 23 in the frame 24 which encircles the lower half of the starting mechanism.

The pull cord or cable 25 is attached to the handle 26 at one end and wrapped around the groove 21 in the dished rim of the starter pulley 20. The pull cord makes one complete turn around the pulley and its other end is secured in the socket 28 which in turn is fastened to the pulley 20 as by the rivet 29 as shown in Fig. 3. The pull cord 25 is threaded between the grooved guide rollers 36 and 3| supported by the frame 24 on the inside and by the plate 32 on the outside with the bolts 33 and 35 providing the shafts on which the respective guide rollers 30 and 3| rotate.

The frame 24 has three bolt holes 35, 36 and 31 for securing it to the crank case I5. The bolt 33 and the bolts 38 and 39 secure the cover 45 which encloses the top of the recoil starting apparatus. The holes 4| and 42 in the frame 26 are in that portion of the wall that extends upwardly in front of the pulley and is indicated as 43 and is provided with an inwardly prjecting arcuate cam surface 44, the inner edge of Which is spaced from the ratchet gear |3 but lies slightly within the rim of the pulley 29.

The dished side of the starter pulley 25 is provided with a semi-cylindrical socket 45 arranged to receive the mating joint 46 of the ratchet '1. The ratchet is made up of a plurality of stamped parts. The surfaces of the socket 55 and the joint 46 are concentric to the pin 48 which extends through the wall of the pulley and is fastened by the pin 49 on one side and has a reduced portion on the other side that passes through a hole in the ratchet parts and is peened to hold them in assembled relation. A second pin 5!! also has a reduced portion extending through the ratchet parts and is peened. However the pin 50 extends in the opposite direction and is arranged to engage the outer perimetral surface of the cam 44 as shown in Figs. 3 and 5. A bolt 5| is secured to the wall of the pulley 20 to support the trap spring 52 that has the bail 5-3 engaging the free end of the ratchet 41 forcing it inwardly to cause the pin 50 to strike the cam 44 or the tooth 54 of the ratchet to engage a tooth in the ratchet gear if the pulley is turned free of the stationary cam 44.

The ratchet being constructed of four or more pieces may be made up of stamping punched to provide the proper contour and with the holes to receive the pins 48 and 50 which when peened thereon secure the ratchet parts as a unit that can be readily hardened and assembled.

As the handle 26 is drawn outwardly the pull cord 25 rotates the pulley 20 in a clockwise direction in Figs. 1 and 5 and the pin 50 rides off the surface of the cam 44, permitting the bail 53 of the trap spring 52 to force the tooth 54 of the ratchet into engagement with a tooth of the ratchet gear l8. Further pull will permit the pull cord 25 to rotate the pulley 20 and the gear l8 with the crank shaft M for three fourths of a revolution when the pin 50 engages the abrupt rise 55 of the cam 44 and forces the ratchet out of engagement with the ratchet gear and the stop 56 on the pulley 20 engages the opposite face of 4 the stop 51 on the frame 24. Thus at the beginning and the end of the stroke the ratchet is held out of engagement with the ratchet gear. As the pull cord 25 is unwound the recoil spring 2| is wound up and when the handle is released the spring 2| returns the pulley 2|] to the starting position as shown in Fig. 3 where the stop 55 on the pulley 20 engages the stop 51 on the frame 24. It should also be noted that the ratchet is in the same plane as the pull cord 25 and the guide pulleys 30 and 3| have deep grooves which permit them to be very close together and allow the handle 25 to be pulled at an angle to the throat formed by the grooves of the guide pulleys without affecting the proper application of force on the starting pulley 25.

The handle 58 of the gasoline hammer is provided with the throttle lever 59 pivoted substantially in the center of the handle 58 and extending in the direction of and beyond the recoil starter. Thus an operator stands the gas hammer on the tool, grasps the handle and gas throttle in the 'left hand directly above the recoil starter and pulls on the pull cord handle 25. Thus a direct pull will not twist the hammer out of the operators grasp and he is enabled to start the tool Without difficulty and has the throttle at hand to control the supply of gasoline fed to the hammer.

In the modified structure shown in Fig. 6 the shaft It has been shortened and has the hub member 56 secured thereto by means of the pin 5!. The outer face of the hub member 55 is provided with a recessed chamber 62 having one or more pockets 63 for receiving the ball members 54. The crankcase I3 is provided with an extension 65 having an auxiliary disposed bearing 55 carrying the shaft 6'1. The inner end of the shaft is provided with an integral head 68 having one or more recesses 69 arranged to receive a portion of a selected ball member 64 to provide an overrunning clutch action therebetween. The outer end of the shaft 61 is arranged to receive the key washer 10 having a radial key section engaging the corresponding slots in the cupshaped plate 12. The sides of the end of the shaft 61 is provided with flattened key surfaces and the washer has an oblong hole arranged to snugly fit the same to prevent relative rotary motion therebetween. The Washer 10 is secured to the shaft 61 by means of the screws 13 and is sufficiently large in diameter to hold the plate member 72 in assembled position and provide a driving connection between the plate and the shaft.

Adjacent its perimeter the plate 12 is provided with a series of openings for receiving the outer ends of the studs 14 which are formed on the flange 15 of the pulley 16. The pulley i6 is in turn journaled on the housing extension 65, making it free to rotate relative thereto. The pulley i6 is provided with a groove 17 arranged to receive several turns of the pull cord 78 which is secured at its inner end to the pulley l6 and is provided with a handle 19 at its outer end which extends through a tangentially disposed housing on the extension 65. A helical flat spring 8| is secured at its inner end to the housing 65 by means of the pin 82 and at its outer end to one of the posts 14 on the pulley 16.

Thus when the handle 19 of the pull cord 18 is drawn away from the housing 65 one of the sockets 69 will receive a portion of the ball 54 when passing one of the pockets 63. Since the socket 69 is insufficient to fully retain the ball 64 the latter acts as a ratchet and causes the 5 hub 60 to be rotated with the shaft 61. This spring recoil starting mechanism is simple and economical in design and provides a ball ratchet member that lends itself to long life with little wear.

I claim:

In an internal combustion percussion hand tool comprising an engine with a crankshaft operated by a timing piston and having a working percussion piston, a, starting mechanism mounted on the crackshaft and having a pull cord operatively connected to extend substantially horizontally and apply cranking forces in a plane lying transverse to the crankshaft when the tool is upright, and a guide handle attached to the engine and having a hand grasp mounted directly in said plane to prevent twisting of the tool to provide control of the upright tool while cranking.

CARL S. WEYANDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 10 Number Name Date 1,647,554 Trapnell Nov. 1, 1927 1,920,765 Rasch Aug. 1, 1933 1,934,935 Luxmore Nov. 14, 1933 1,981,764 Warsop Nov. 20, 1934 15 2,333,419 Fitch Nov. 2, 1943

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