US 3572188 A
Description (OCR text may contain errors)
March .23, 1971 W, s, CHRISTIAN, JR 3,572,188
HIGH SPEED RATCHET WRENCH Filed May 21, .1969 2 sheets-sheet 2 INVENTOR. WILL/1M 5. CHRIST/ANW?.
BY @d/6W@ United States Patent Oce 3,572,188 Patented Mar. 23, 1971 3,572,188 HTGH SPEED RATCHET ENCI-I William S. Christian, Jr., Rte. 4, Lafayette, Ala. 36862 Filed May 21, 1969, Ser. No. 826,570 Int. Cl. B25b 13/46 US. Cl. til-57.46 10 Claims ABSTRACT F THE DISCLOSURE A ratchet wrench for high speed, low torque and low speed, high torque operation has a reel inside a casing rotatable on an axial shaft. A tirst pawl carried by the reel engages a ratchet wheel secured to the shaft to turn the same when the reel turns. A second pawl carried by the cover plate engages the ratchet wheel to turn the shaft when the casing lis turned by radially-extending handles. A cable wound on the reel moves axially of the handle for fast turning the reel when a removable extension is pulled from one of the handles.
This invention pertains to high speed ratchet wrenches and has as a principal object the provision of a ratchet wrench which can be operated at low speed with high torque or alternatively at high speed with low torque.
Heretofore, ratchet wrenches operable at low and high speeds have been constructed so that special control knobs, pins or adjustment screws must be operated to permit the wrench to turn selectively at high or low speed. Such prior wrenches employ gears, clutches and other complicated parts.
The present invention is directed at a ratchet -wrench which has a ratchet wheel and casing cover on which ride two pawls. When the wrench is turned at low speed to exert high torque one pawl is effective to turn the ratchet wheel. When the wrench is turned at high speed to exert low torque the other pawl is ineffective. Turning of the wrench at high speed is effected by pulling a removable extension of the turning handle of the wrench.
Various objects, features and advantages of the invention will become apparent upon reading the following specication together with the accompanying drawing forming a part thereof.
Referring to the drawing:
FIG. 1 is an isometric View of a ratchet wrench ernbodying the invention.
FIG. 2 is an enlarged partial sectional view taken on line 2 2 of |FIG. 1.
FIG. 3 is a fragmentary sectional view taken on line 3-3 of FIG. 2.
FIG. 4 is an exploded perspective view of parts of the ratchet wrench.
FIG. 5 is a fragmentary elevational View of the bottom end of the wrench showing a modified form of connection between the tube and actuating handle.
`FIG. 6 is a bottom plan view of the inside of the cover plate and ofthe pawl assembled thereon.
Referring to the drawing, there is shown a ratchet wrench 10 having a cylindrical casing 12. The casing has an integral circular end wall 14. The other open end of the casing is provided with a circular cover plate 16 held in place by screws 18 inserted in threaded holes 19 in the open end of the casing 10. Aligned central holes 22 and 24 are provided respectively in end wall 14 and cover plate|16.
Shaft 25 carrying xed ratchet wheel 26 at its center extends through holes 22, 24. Shaft 25 terminates in square heads 27 and 28 which `can be inserted in wrench on shaft 25 is a generally cylindrical reel 30. The shaft 25 extends through central hole 32 in the reel. The reel 30 has a circumferential groove 34 defined between spaced annular flanges 36, 38. In this groove is wound a cable 40. Cable 40 extends through lateral hole 42 and a tube 48 threaded in a nipple 50 about the hole `42, and terminates in a knotted end y40 within a removable handle extension 49. This handle extension 49 is tight fitted in the open end of the tube 48 by its reduced diameter end 49 and shouldered at 49 to be limitedly received therein. A bushing 51 in the lower end of the tube 48 serves to center the cable 40 therein as the cable 40 is extended or retracted. Tube 48 and extension 49 serve as one handle for the wrench.
Reel 30 has a nipple 52 extending axially of the lower flange 36. On this nipple 52 is wound a coil spring S3. The outer end of the spring is secured by a pin 5-4 to the inner face of the cylindrical casing 12. This pin 54 extends through hole 55 inthe outer end of the spring and is seated .in blind bore 56 in the casing. Another pin 58 is inserted through hole 60 in the inner end of the spring 53 and is engaged in hole 62 in the reel nipple 52.
Reel 30 carries a pivotable pawl 64 mounted by a pin, screw or bolt 66 in a recess 68 provided in inner peripheral edge 70 of top ange 38. The outer face of this pawl 64 is substantially coplanar with the outer face of ridge 70. A spring 72 bears against the outer edge of the pawl 64 and is engaged in a hole 73 formed in ridge 70, FIG. 4. A tooth 74 of the pawl 64 rides on the periphery of ratchet wheel 26 to engage teeth 31 thereof. As shown clearly in FIG. 3, the ratchet wheel 26 can turn clockwise while the reel 30 remains stationary or is turned counterclockwise and both the reel 30 and ratchet wheel 26 will turn together when the reel is turned clockwise. Since pawl 64 is recessed in the end of flange 38, the trailing end 68 of recess 68 will cooperate with screw or bolt 66 in bearing the load applied to the pawl when the rcel is turning the ratchet wheel 26 and shaft 25.
A second pawl is pivotally mounted on the under face of the cover plate 16. This pawl has pivot screw, bolt or pin -82 seated in a hole 84 in cover plate 16. The tooth 88 of the pawl bears on the periphery of the ratchet wheel 26, The axial thickness of the teeth 31 of the ratchet wheel is slightly greater than the total thicknesses of pawls 64 and 80. As clearly shown in FIG. 2, pawl 80 is disposed in a plane outward of pawl 64. Pawl tooth 88 extends in the same direction as pawl tooth 74 on the ratchet wheel. Coil spring 89 bears against tooth 88 and is seated in a threaded hole 9i) in the inside of the casing. Hole 90 receives a set screw 91. Springs 72 and 89 respectively press the teeth 74 and `88 against the ratchet wheel. Reel 30 carrying pawl 64 can turn on or with shaft 25 without interference by pawl 80.
When casing 12 is turned, pawl 80 engaging the ratchet wheel will cause the ratchet wheel and shaft 25 to turn also. The casing 12 can be turned by grasping handle 48-49 and turning the casing axially while either head 27 or 28 is engaged with a socket tool being turned. This will exert high torque at low turning speed. An auxiliary wrench handle 92 is provided. This handle k92 has an externally-threaded end 93 screwed into internally-threaded nipple 94 which is axially aligned with nipple 50 and handle tube 48 diametrally of the casing. Both handle 92 and tube can be grasped for exerting a very large turning torque.
If it is desired to turn shaft 25 at high speed, such as when loosening or starting a nut or bolt, the handle extension 49 can be grasped and pulled axially outwardly of the tube 48. It may pull the cable 40 a distance A equal to 24-26 inches below the bottom end of tube 48 in order to get the desired number of revolutions of the square drive 27 or 28. This will result in turning of reel 30 at high speed inside the casing 12 without turning the casing. The pawl 64 engaged with ratchet wheel 26 will turn this wheel and shaft 25 while the ratchet wheel slips past pawl 80. For such complete pull on extension 49 the reel, ratchet wheel and shaft will make about five or six turns. At the same time, coil spring 53 will wind up the cable 40 with greater tension. When the handle extension 49 is released the` unwinding spring 53 will rewind cable 40 as shown in FIG. 5 and will return the extension 49 axially inward to the position shown in FIG. 2. It will be noted that fast turning of shaft 25 is possible without interfering independently of pawl 80. Thus fast turning of the shaft is possible at any time. Furthermore, the wrench can be turned at any time by rotating handle 48 or 92 to turn casing 12 regardless of the position of extension 49 and independently of pawl 64.
What I claim is:
1. A ratchet wrench comprising cylindrical casing; a shaft extending axially of the casing, said shaft having tool driving heads at opposite ends; a ratchet wheel in said casing, said wheel having teeth extending circumferentially around the wheel; a reel rotatably mounted on the shaft in the casing; a coil spring wound around the shaft and connected between the reel and casing to resist turning of the reel with respect to the casing; a cable wound circumferentially on the reel and extending outwardly of the casing for turning the reel in the casing when the cable is pulled outwardly of the casing; a first pawl carried by the reel and spring biased to engage the teeth of the ratchet wheel for turning the ratchet wheel and shaft when the reel is turned in the casing; and a second pawl carried by the casing and spring biased to engage the teeth of the ratchet wheel for turning the ratchet wheel and shaft with the casing when the casing is turned, said second pawl being disposed laterally of the reel so that the reel and first pawl turn in the casing independently of and without interference by the second pawl.
2. A ratchet wrench as defined by claim 1, further comprising an open tube extending radially outward of the casing, said cable extending axially through said tube; a handle extension removably secured to the outer end of the tube, said cable being attached to the handle extension so that upon being removed therefrom the cable can be pulled to cause the reel to turn and rotate the ratchet wheel and shaft in the casing.
3. A ratchet wrench as defined by claim 2, further comprising an auxiliary cylindrical handle detachably secured to the casing in diametral alignment therewith, so that the casing can 'be turned selectively by grasping either handle and by grasping both handles, whereby the ratchet wheel and shaft will turn with the casing in one direction, and whereby the ratchet wheel and shaft will remain stationary while the casing is turned in opposite direction and while the second pawl slips along the ratchet wheel.
4. A ratchet wrench as defined by claim 1, wherein said reel has two annular anges, said cable being wound between the fianges; and a nipple formed integral with and axially of one of the flanges, said coil spring being wound around said nipple with one end thereof of the spring being secured to said nipple.
5. A ratchet wrench as defined by claim 1, wherein said reel has two annular lianges, said cable being wound between the fianges, one of said iianges having a peripheral axially extending ridge thereon, said first pawl being pivotally mounted at said ridge with its outer side coplanar with the ridge; and a pin pivotally mounting the first pawl at said ridge, said ridge serving to cooperate with said pin in bearing a load imposed on the first pawl when the reel is turning the ratchet wheel and shaft to rotate a load engaged with one of said heads.
6. A ratchet wrench as defined by claim 5, wherein the other one of said two flanges of the reel has a nipple formed integral therewith, said coil spring being wound around said nipple with one end of the spring secured to said nipple.
7. A ratchet wrench as defined by claim 1, further comprising a pair of nipples integral with and extending radially outward of the casing in diametral alignment therewith; and a pair of handles detachably engaged in said nipples respectively for turning the casing, said cable extending axially of one of the handles and movable therein for winding the cableon and unwinding the cable from the reel while the reel turns in the casing.
8. A ratchet Wrench as defined by claim 2, wherein said reel has two annular fianges, said cable being wound between the fianges, one of said fianges having a peripheral axially extending ridge thereon, said first pawl being pivotally mounted at said ridge with its outer side coplanar with the ridge; and a pin pivotally mounting the first pawl at said ridge, said ridge serving to cooperate with said pin in bearing a load imposed on the first pawl when the reel is turning the ratchet wheel and shaft to rotate a load engaged with one of said heads.
9. A ratchet wrench as defined by claim 8, further comprising an auxiliary cylindrical handle detachably secured to the casing in diametral alignment therewith, so that the casing can be turned selectively by grasping either handle and by grasping both handles, whereby the ratchet wheel and shaft will turn with the casing in one direction, and whereby the ratchet wheel and shaft will remain stationary while the casing is turned in opposite direction and while the second pawl slips along the ratchet wheel.
10. A ratchet wrench as defined by claim 9, wherein the other one of said two fianges of the reel has a nipple formed integral therewith, said coil spring being wound around said nipple with one end of the spring secured to said nipple.
References Cited UNITED STATES PATENTS 1,903,514 4/1933 Merriman et al. 81-57.46 2,365,839 12/1944 Pike 81-58.1
TRAVIS S. MCGEHEE, Primary Examiner U.S. C1. X.R. fil-58.1, 61