US 935268 A
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A'. LEVEDAHL. THROTTLE VALVE FOR PNEUMATIC DRILLS.
APPLICATION FILED JUNE 1, 1908.
Patented Sept 283909.
To all whom it mag concerns I r UNITE STAES TENT OFFICE.
.axnr. rnvnnant, or annorm, rumors,
ASSIGNOR ,10 AURORA AUTOMATIC Be it known that I, Am Lnvnnann, a citi zen of the United States, and a resident of Aurora, 1n the county of Kane and State of Pneumatic Drills;
Illinois, have invented certain new and useful Improvements in Throttle-Valves for and I do hereby declare that the following is a full, clear, and exact dmcription thereof, reference being bad to; the accom anying" drawings, and to the numerals of reference marked thereon, which.- form a part of this specification. g This invention relates to improvements in throttle valves of the kind used'in portable pneumatic tools, such as pneumatic drills having an air driven motor and provided with two handles one of whichcontains the throttle-valve mechanism for controlling admission of air to the motor, and the invention refers more specifically to an improved construction and arrangement of the parts associated with the throttle valve by means of which the. valve is operated by the hand of the operator which gras s the handle of the tool and is adapted to be automatically v closed when the operatorsgrasp is released.
The invention consists in the matters here- 'inafter set forth and more particularly pointed out in the appended claims.
In the drawings :Figurel is a side elevati'on of a'tool handle containing a throttle- Fig.2.
valve embodying my invention. Fig. 2 is a view in central longitudinal section taken through'the tool handle, and the throttle valve mechanism. Fig. 3 is a section, on a slightly larger scale, taken upon line 3--3 of Fig. 4 is a section. on a larger scale taken upon line 4. l of Fig. 2. Fig. 5 is a sectional view on a larger scale taken upon line 5-5 of Fig. 2. Fig. 6 is a View in side elevation of the endwise sliding cylinder in the tubular handle. Fig. 7 is a side view of the guide disk for the valve-stem.
As. shown in said drawings, 1 indicates the tubular handle of the tool in which is contained the throttle valve mechanism and which is grasped by the operator during the time the drill is in operation. Thehandle 1 is provided with a bore or passage extend ing through-the same from end to end. Over the portion of the handle 1 which is grasped by the operator thereis fitted an exteriorly knurled cylindric sleeve forming a hand grip. The throttle valve illustrated 1n the drawings is located in the bore of the handle 7 Specification of Letters Patent.
7 Application filed June 1, 1908 Serial No. 435,865.
I rnnorrtn-vanvn son PNEUMATIC n'ruLLs.
Patented Sept. 28, 1909.
land adjacent to that portion of the said handle which is surrounded by the sleeve 2'. v The bore or passage of the handle 1, in which the throttle valve is located, opens at its ends through both ends ofthe handle', and
one end of the bore constitutes a supply passage or inlet for the air or other fluid under pressure. In said inlet end of the bore or passage is inserted a sleeve or nipple 3 having interior screw threads for attachment thereto of the pipe or hose through which air is supplied to the tool. Said nipple 3 has external screw-threads engaging the corresponding -screw-threads in the end of said bore-0r passage which is enlarged to receive it. Within said passage and near the inlet end is a longitudinally arranged valve stem 4 which isprovided with a valve disk 5, adapted to bear on a valve seat formed by an inwardly extending ofiset or shoulder 6- handle sotliat the pressure-of the air enter ing'the bore of the handle tends to press the said valve disk against its seat, or to hold.
the valve closed. The opposite or inner end.
of the valve stem bears endwise against a cylindric block 7, which is-adapted to slide endwise in the bore of the tube 1. A cylindricseat is formed in the tube 1 in which the cylindric block 7 fits and slides, andsaid block is provided at its opposite sides with longitudinal grooves or channels 11, 11 to permit the passage of air through the tube past mid block. The inner end of said valve stem is provided with a conical point which engages a conical recess in the adjacent end of said block.
v The nipple 3 is provided at its inner end with a rigidly attached guide disk 8 having a guide aperture formed centrally therein, through which passes the adjacent or outer end of the valve stem 4. The said guide disk 8 is provided with curved slots or apertures 9, 9 formed concentric with the guide aperture therein and through which air passes to the valve. Between the guide disk 8 and the valve disk 5 is a-coiled actuating spring 10 y which the valve disk is held normally against the valve seat. a I
Provision is-made for operating the throttle valve for admission of air to the motor as follows: Secured to one side of the said sliding block 7 at right angles thereto is an outwardly extending stud 12. Said stud of an annular shoulder 14 on the tube 1, against which the inner-end of the sleeve abuts, and by contact of the opposite or outer end of 'said sleeve with an outwardly extending annular flange 15 on the nipple 3. Pivotally supported upon the said sleeve 2,
- bymeans of pivot studs 16, 16, is a hand lever 17 which is provided with lateral arms 18, 18 extending from the pivoted end of the lever at opposite sides of the sleeve 2, and through which the pivot studs 16, 16 are inserted. The opposite or swinging end of said lever 17 extends from its pivoted end outwardly or toward the inlet end of the 20 tube 1. At its ivoted end the said lever 17 is provided with an aperture 19 through which the outer end'of the stud 12 extends.
The said aperture 19 is arranged substantially in transverse alinement with the pivot studs 16, 16; the arrangement of the parts being such that when the free end of the lever is pressed toward the tube the aperture therein which engages the stud 12 will be moved or shifted endwise of the tube and toward its outer or inlet,end, and a like movement will be transmitted to the sliding block 7 through the medium of the said stud 12: The said sliding block, by its endwise pressure on the valve stem, will shift the same endwise against the action of the spring 10 to effect the opening of the valve.
In order that the parts gripped by the hand of the operator may be as small in diameter as possible, the lever 17 is transversely curved and has its inner side concave to correspond with the curvature of the ,sleeve 2. By this construction in the lever,
- when said lever is pressed a ainst the sleeve 2, it will afford a substantial y cylindric surface .to be held or gripped by the operator during the handling of the tool. The tube or handle 1 at its exit end, or that which is attached to the tool, is shown asprovided with a screw-threaded nipple 20, by" which it is connected With the casing 01'' the tool.
In the operation of the throttle valve described, the hand of the operator is applied around the sleeve 2 and the lever 17 in such manner that, by the asp of the hand, the
= lever is swun inwar ly and the cylinder 7 thereby move longitudinally toward the inlet end of said handle; A corresponding movement will be imparted to the valve stem 4 and the'vaive disk-5 will be moved against the action of the spring 10 and the pressure of the incoming motive fluid or air away The motive fluid or air will then pass through the apertures 9,9 of the guide disk 8, through the o ening in the valve seat, and through the cliannels 11', 11
of the cylinder '7 to the motor. When the operators grip upon the handle is released the valve disk. 5 will be shifted to its closed position by the action of the spring 10 aided by the air-pressure.
An advantage gained by the construction described is that the throttle valve will close automatically when the pressure of the hand on the handle of the tool is released, thereby insuring the stoppage of the motor in case the handle of the tool should slip'from the grasp of the operator.
It is to be understood that the presence of the sleeve 2 is not necessary to the operation of the throttle valve described, althou h the same is of advantage because affor ing a pivotal support for the hand lever 17 adapted to be easily placed upon and removed from the .tube 1. In case the said sleeve 2 is omitted, the hand lever 17 will be pivotally connected with the tube 1 in some other convenient manner. The employment of sa d sleeve 2,as a separate removable member, is of advantage, moreover, because incase a self-closing valve be not desired, the sleeve 2 with the hand-lever may be removed from the tube, and for the same may be substi- -a throttle valve embracing an endwise movable valve stem, an endwise sliding block fitting within the bore of the handle and adapted to give endwise movement to the valve stem, said sliding block being provided with a longitudinally arranged air assage and with a rigidly attached outward y extending stud, and said handle being provided with a longitudinal slot through which said stud extends, a hand lever extending lengthwise of said handle at one side of the same and pivotally connected at one end with said handle by a transverse pivot, the pivoted, end of said handle being engaged with the outwardly extending stud on the sliding block, and a spring applied to hold the valve in its closed position and the free end of the hand lever at a distance from the handle.
2. The combination with a pneumatic motor handle provided with a. bore or passage, of a throttle valve embracing an endwise movable valve stem, an endwise sliding block fitting within the bore of the handle and adapted to act endwise on said valve stem, said block being provided with alongitudinally arranged air passage and with a.
studrigidly attached thereto and said handle being provided with a longitudinal slot through which said stud extends, and a hand lie lever pivotally supported upon the said handle and adapted at its pivoted end for engageinent with the outwardly extending I .'-:tu l of the sliding block, the said hand lever being provided with lateral arms which ex- I tend at opposite sides-'01 the handle and \\'lll('ll are pivotally connected with the same. i 3. The rolnliination with a. pneumatic inotor handle provided with a hore or pass I of a throttle. valve embracing an endwise movable valve. stem, an eudwise. slidinghlnek fitting closely in the bore of the handle and adapted to act endWise on the valve stem, said block being provided with a longitudinally arranged air passage and with a stud I rigidly attached thereto, a sleeve surrounding the handle, said handle and sleeve being I provided with longitudinal slots through which the said studs outwardly extend, a hand lever which extendslengt-hwise of the handle, which is pivoted at one end to said sleeve and engages at its pivotalend with Raid stud, and a spring acting on the valve stem to hold the valve normally closed and to maintain the free end of the hand lever at a distaiuefroin the. handle. i
In testimony, thatl claim the foregoing a.' my invention I aflix my signature in the presence of two wit-nesse, this 27th day of .\l a v l 1909.
AXEL LE EDAHL. V Wl'ituesses: ll. lli'ii-iu, (l). llannnununn.