US 3666027 A
A portable tool including a housing having a rotary pneumatic motor disposed therein and coupled to a tool spindle. Compressed air is delivered to the motor by conduit means which includes passage means in a handle dependent from the housing. A throttle valve is disposed within the handle and is controlled by a trigger pivoted upon the handle. The trigger and handle are provided with novel adjustable stop means to limit trigger movement.
Description (OCR text may contain errors)
United States Patent Sauerwein et al.
 3,666,027 [451 May 30, 1972  HANDLE AND TRIGGER CONSTRUCTION  Inventors: William D. Sauerwein, Joppa; Robert A.
Meloni, Baltimore; Harvey J. Walter, Joppatown, all of Md.
The Bhick and Decker Manufacturing Company, Towson, Md.
 Filed: Aug. 1, 1970  Appl. No.: 65,954
52] U.S.Cl ..173/169,173/l70 51] lm. Cl ..B23b45/04 5s FieldofSeai-ch ..l73/l69,l63,l70,l8
 References Cited UNITED STATES PATENTS Maurer ..173/170 X 2,898,893 8/1959 Rohrer et a1 ..173/l70 X 3,037,740 6/ 1962 Sheps et a1. 3,352,368 11/1967 Maffey .1 173/169 Primary Examiner-David H. Brown Attorney-Leonard Bloom, Joseph R. Slotnik and Edward D. Murphy 57 ABSTRACT A portable tool including a housing having a rotary pneumatic motor disposed therein and coupled to a tool spindle. Compressed air is delivered to the motor by conduit means which includes passage means in a handle dependent from the housing. A throttle valve is disposed within the handle and is controlled by a trigger pivoted upon the handle. The trigger and handle are provided with novel adjustable stop means to limit trigger movement.
SCIainsADrawingFigures Patented May 30, 1972 3,666,027
INVENTORS WILLIAM D. SAUERWEIN ROBERT A. MELON! ATTRNEY HANDLE AND TRIGGER CONSTRUCTION SUMMARY OF THE INVENTION The present invention is directed to a novel adjustable trigger construction for a variable speed, portable tool or the like. The trigger is pivoted upon, for example, a tool handle to operate a throttle valve, electrical or electronic speed control, or the like, and includes adjustable means integrated therewith and cooperable with means rigid with the handle to vary the extent to which the trigger can pivot and therefore the speed of the tool. The adjustable means is adapted for easy, manual adjustment, includes means for retaining it in incrementally adjusted positions, and is constructed so that the tool will operate even if the adjustable means is removed or fails. Furthermore, the adjustable means is safe, compact and convenient, involves a minimum of parts and expense, and presents a neat and aesthetically pleasing appearance.
Main objects of the present invention are to provide a novel pivotal, adjustable trigger construction for a variable speed power tool or the like, which construction is compact and is integrated with the trigger and its mount, and is quickly and easily manually adjustable while being retained in incrementally adjusted positions.
Further important objects are to provide a novel trigger construction of the above character which will function in the absence of or upon failure of the adjustment construction, which includes a minimum of separate parts, and wherein most of these parts are concealed or out of the way thereby presenting a neat and aesthetically pleasing appearance.
Additional important objects are to provide a novel trigger construction of the above character which is relatively inexpensive to manufacture, rugged in construction, and safe and reliable in use.
Other objects and advantages will become more apparent from a consideration of the detailed description to follow taken in conjunction with the drawings annexed thereto.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view illustrating a portable pneumatic tool embodying the present invention and showing the trigger construction in one adjusted position;
FIG. 2 is a view of a portion of FIG. 1 and showing the trigger construction in another adjusted position;
FIG. 3 is an enlarged sectional view of the structure of FIG. 1 taken along the line 3-3 thereof; and
FIG. 4 is an enlarged sectional view of FIG. 2 taken along the line 4-4 thereof.
BROAD STATEMENT OF THE INVENTION Broadly described, the present invention relates to a portable tool comprising a housing, a variable speed motor in said housing and adapted to be connected to a power source, control means for varying the speed of said motor, a trigger pivoted on said housing and interconnected with said control means and movable in a first direction to turn said motor off and in a second direction to turn said motor on, said trigger having an outer portion adapted for finger engagement during operation of said tool and an inner portion generally inaccessible to the fingers of an operator during tool operation, engageable abutment means rigid with said housing and trigger to limit movement of said trigger in said second direction, means on said trigger at the inner portion thereof for adjusting said abutment means relative thereto whereby to adjust the range of pivotal movement of said trigger in said second direction and correspondingly the speed of said motor.
DETAILED DESCRIPTION Referring now more specifically to the drawings, the present invention is seen embodied in a pneumatic impact wrench generally indicated at 11 in FIG. 1. However, it is to be understood that this tool is for purposes of illustration only.
With this in mind, the wrench 11 includes a housing comprising a motor housing 13, a clutch housing 15, a rear cover 16, and a handle 17 secured together in suitable fashion. A rotary pneumatic motor 18 is disposed in the motor housing 13 and includes a rotor 19 having fore and aft stub shafts 21, 23 rotatably supported by bearings 25, 27 in end plates 29, 31. The rotor 19 carries a plurality of radially disposed vanes 33 adapted to slidably engage the inner wall of a cylinder liner 35 and trapped endwise between the end plates 29, 31.
The stub shaft 21 is splined to a cam driver 37 which is coupled to a dog 39. A clutch pin 41 connects the dog 39 and a clutch body 43, and the dog 39 is adapted to engage a jaw 45 formed on a clutch shank 46. The forward end of the shank 46 forms a tool spindle 47 to which a suitable tool bit, e.g. a wrench socket, can be fixed and is supported within the housing by a bushing 49. The dog 39 is adapted to engage and constantly drive the shank 46 at low torque levels and intermittently engage or impact against the shank 46 at higher torque levels.
Pressurized air is delivered to the tool 11 from a source through a conduit (not shown) fastened to a coupling 51 threaded into a valve cavity 53 in the handle 17. A valve member 57 is positioned in the cavity 53 and is normally biased by a compression spring 59 into seated relation with a valve ring 55. The valve member 57 has a stem 61 extending through an opening 63 in the ring 55 and is slidably received in an opening 65 in the handle 17.
When the valve 57 is unseated from the ring 55, pressurized air is delivered to passage 67 and port 69 in the handle 17 and a reversing valve sleeve 71, respectively. In the position of the parts shown in FIG. 1, this air then passes out through a port 73 in sleeve 71, through passages (not shown) in the housing 13 and rear cover 16, and then to the motor 18. Air is exhausted from the motor 18 through ports 75, 77 in the liner 35, ports 79, 81 in housing 13 and sleeve 71, and out to atmosphere.
When it is desired to reverse operation of the motor, a spool 83 positioned in the sleeve 71 is pushed rearwardly or toward the right, as seen in FIG. 1. Now, pressurized fluid flows from passage 67 and 69 out through port 85, and to motor 18 through other passages (not shown) in the housing 13 and rear cover 16. Air is now exhausted from motor 18 through ports 75, 77 ports 87, 89 in housing 13 and sleeve 71, and then to atmosphere. Desirably, detent means (not shown) retains the spool 83 in these positions.
A trigger, generally indicated at 91 in FIGS. 1 and 2, is provided on the handle 17 for actuation of the throttle valve. As shown, the trigger includes a body 93 set partially within a pocket 94 in the handle 17 and pivoted at its lower end thereon by a pin 95. The body 93 has an inner portion which is inaccessible to the operators fingers during normal tool operation and formed with a recess 97 which defines first and second abutment surfaces 99, 101. A projection 103 formed integral with the handle 17 and located within the pocket 94 is receivable in the recess 97 and defines first and second abutment surfaces 105, 107 adapted to engage the abutment surfaces 99, 101 and limit pivotal movement of the trigger body 93 in both directions.
The trigger body 93 has a surface 109 adapted to engage the end of the valve stem 61. The body 93 also has an outer portion including a concavely shaped upper portion 111 which accommodates one or more fingers of the operator when his hand is on the handle 17. Thus, with his hand so positioned, the operator can easily pivot the trigger body 93 in a clockwise direction, as seen in FIGS. 1 and 2, whereby to move the valve stem 61 downwardly and unseat the valve body 57 from the ring 55. This, in turn, allows pressurized air to pass into the motor 18 and rotates the rotor 19 and the shank 46 and spindle 47. Clockwise pivotal movement of the trigger body 93 is limited by engagement of the surfaces 99, which, in turn, limits the extent to which the valve 57 can move away from the ring 55. When the trigger body 93 is released, the spring 59 moves the valve body 57 back into seated relationship with the ring 55 (to shut off the tool) and the valve stem 61 pivots the trigger body 93 in a counterclockwise direction. Engagement between surfaces 101, 107 limits pivotal movement of the body 93 in this direction and prevents the body 93 from coming completely out of the pocket 94.
It is desirable that means be provided to adjust the throttling action of the valve body 57. To this end, the effective position of the abutment surface 99 relative to the abutment surface 105 is adjusted so that the extent to which the trigger body 93 can pivot in a clockwise direction is correspondingly adjusted. This is achieved by a screw 113 which is threaded into the body 93 and having an end 115 adapted to extend beyond the surface 99.
FIG. 1 illustrates the screw 113 withdrawn so that its surface 115 does not protrude from the surface 99. In this position, full pivotal movement of the trigger 93 is allowed and the valve 57 can open fully. FIG. 2, on the other hand, shows the screw 113 adjusted so that its surface 115 extends beyond the surface 99. Now, the screw surface 115 engages the surface 105 before surface 99 does and correspondingly limits allowed pivotal movement of the trigger 93 and the extent to which the valve 57 can open.
The screw 1 13 is provided with a knurled head 117 which is outside the trigger body 93 but is behind the finger portion 111. This allows the operator to easily adjust the screw 113 while partially concealing it and rendering it inaccessible during tool operation. However, to resist inadvertent or accidental movement of the screw 113, a detent comprising a ball 119 and spring 121, is set into a pocket 123 in the trigger body 93, and cooperatively engages the knurled head 117, as seen in the drawings. It will be appreciated, however, the screw 113 can be finger turned against the holding force of the ball 119 and spring 121.
It will be appreciated that the handle 17 (which generally is cast metal) simply is formed with the pocket 94 and the integral projection 103. The trigger body 93, on the other hand, is a relatively small and replaceable element and can be molded using a suitable plastic. The screw 113 is threaded directly into the body 93 (rather than the handle 17) and the ball and spring 119, 121, also located therein so that this trigger assembly can be packaged and assembled to handle 17 as a separate unit. Thus, this trigger construction described achieves maximum efficiency, convenience, and reliability, with a minimum of cost, and, in addition, by the concealed ball, detent and screw, presents a neat and aesthetically pleasing appearance devoid of unsightly or unattractive parts.
By the foregoing there has been disclosed a novel trigger construction calculated to fulfill the inventive objects set forth, and while a preferred embodiment of the invention has been illustrated and described in detail, various additions, substitutions, modifications, and omissions may be made thereto without departing from the spirit of the invention.
1. A portable tool comprising a housing, a variable speed motor in said housing and adapted to be connected to a power source, control means for varying the speed of said motor, a trigger pivoted on said housing and interconnected with said control means, and movable in a first direction to turn said motor off and in a second direction to turn said motor on," said trigger having an outer portion adapted for finger engagement during operation of said tool and an inner portion generally inaccessible to the fingers of an operator during tool operation, engageable abutment means rigid with said housing and trigger to limit movement of said trigger in said second direction, means on said trigger at the inner portion thereof for adjusting said abutment means relative thereto whereby to adjust the range of pivotal movement of said trigger in said second direction and correspondingly the speed of said motor.
2. A tool as defined in claim 1 wherein said abutment means on said trigger includes a screw threaded therein and engageable with said abutment means on said housing.
3. A tool as defined in claim 2 which includes detent means on said trigger engageable with said screw to releasably retain said screw in threadedly adjusted position.
4. A tool as defined in claim 3 wherein said detent means includes a compression spring and ball disposed in a pocket in said trigger, said ball being engageable with serrated head on said screw.
5. A tool as defined in claim 3 wherein said trigger includes a finger accommodating portion, said screw being located behind said finger portion.