US1792888A - Portable percussive tool - Google Patents

Description

Patented Feb. 17, 1931 i n.' RRNRDICT, or cOsCOB, CONNECTICUT, V AssIGfNOR To CHTOAGO PNEUMATIC earns-T vOrmes j TOOL oeMrANY, OF Nnwv YORK, N. Y., A CORPORATION or NEW JERSEY PORTABLE rnRoUssrvn TOOL Application led April 5, 1928'. Serial No. 267,624.

rl`his inventionr relates toportable` power operated percussive tools adapted to be manually supported and directed rto. the work. lt has practical application to tools for hand drilling and demolition work generally.

. @ne Cbject of theinvention is-to provide improved means for relieving the operatorv of the sho-ok and reactionof vthe tool when in operation. Another Object is to protect the tool against the destructive eects of vibration. Another object is to support and to control the operation of thepercussivefmotor of such a tool in an improved manner. Other objects will be apparent from the detailed description which follows.:

ln order toillustrate the invention one concrete embodiment thereof is4 shown in the accompanying drawings in which:

Fig. 1 is a vertical sectional view showing a portion of the percussive'motorin elevation, the latter being in its retracted lor non operativeposition;A and Fig. 2 is a viewsimilar to Fig. 1 showing the motor in running position. A g

The invention comprises a. member3 generally cylindrical in `form providing an elon-` gate chamber 3e in which is slidablyA mounted a percussive motor A adapted-to impart its blows to a drill steel or other working tool B which extends into the forward or barrel end of motor A. Cylinder member 3 isf arranged to be manually supported 4and oontrolled by one or more handles 4, which may be integral with or secured to member 3. In the present instance the handles form portions of a T head or rearward extension 5 secured to member 3 in any suitable manner' as by bolts (not shown). Backhead 5 is hollow and forms a portion of the chamber 3a in which motor A moves, a bearing ring (i and suitable packing' means being provided be` 'tween backhead 5 and cylinder 3 for a pure pose presently to be described. The admis-y ranged to ent-er the rearward or handle por-V tion of chamberV 3a.

Motor A has a head slidablytting the has suitable packing means at 16 and controls one orinore radial ports 17 extending through the wall of cylinder member 3., The rearward portion of head 10 is reduced in diameter and communicatesv freely with the space between the head 10 and bearingring 6.V

Motor A and supporting cylinder 3 cooperate to divide the elongate chamber 3a of the latter into three distinct parts or chambers, which vary inysize with the'movement of motor A. Thethree parts comprise. the

live air .port or chamber rearwardly of bear@ ing ring 6 and into which motor extension 11 extends, the intermediate or exhaust chamber between the head 10 and bearing ring 6 which communicates with atmosphere through ports 17 when the mot-or moves to the position` shown in Fig. 2, and the cushion chamber provided between motor head 10 and packing ring 13.` The opposed pressure areas of motor A provided by extension 11 (which is subjected to pressure in the live air chamber) on the one vhand and by the forward face of head 10 on the other (which is subjected to thepressure in the cushion chamber) are differential in size, the area presented by extension 11 being somewhat Ythe larger so that when throttle valve 8 is open the pressure of the admitted motive iiuid operates to move motor A` forwardly. Extension 11 has an axial bore as indicated which serves to conduct a portion of the pressure fluid in the live air chamber to the percussive motor to operate the same.

Motor A may be of any suitable or desired type. As shown, it comprises a hammer piston 18 whose reciprocations are controlled by an automatic pressure thrown sleeve valve 19 disposed in VaV valve box 20 provided with a lidZl, .the Valve parte bei-ugidiSpQSfl Within' .roo

head and securely held in place by extension 11. The exhaust of the motor is discharged into the annular chamber produced by the reduced rearward portion of head 10.

In order to cushion the forward movement of motor A and to return the'motor to its rearward or inoperative position (Fig. 1), means are provided for admit-ting a charge of pressure liuid to the cushion chamber provided between head 10 and packing ring 18. By preference one charge is admitted to the cushion chamber when the tool is started and another charge is directed thereto when the tool is stopped, there being no supply of fluid to thel cushion chamber while the tool continues in operation. rl`he preferred arrangement includes a passage 22 in cylinder 3 which opens into the cushion chamber on the one hand through a port 22a and terminates in a port 22o adjacent the fluid pressure inlet of the tool. VPort 22?) is controlled by the head of a plunger 23 which by preference takes the form of an extension on throttle valve 8. Adjacent the head of extension or plunger 23 is an annular groove 24 ot sutlicient width to admit a charge of pressure fluid to passage 22 when the throttle valve moves from the closed position shown in Fig. 1 to the open position shown in Fig. 2, and another charge when the throttle valve moves back to closed position. 1n either the fully closed or fully opened position of the valve, port 22?) is cut olif by plunger 23 from communication with the motive fluid inlet. Accordingly, when the operator actuates lever 9 to open throttle valve 8, a charge of pressure fluid goes through passage 2Q to the lcushion chamber, which charge is compressed by the forward movement of motor A due to the proportionately greater area of extension 11 which is subjected to the live motive fluid. The forward movement of motor A continues until the edective pressure in the live air chamber is equalized by the effective pressure in the cushion chamber. Motor A goes into operation as soon as the advancing movement of the motor places ports 17 in communication with the exhaust portion of chamber 3a (Fig. 2). The ruiming position of motor A in cylinder 3 is determined to a certain extent by the pressure applied by the operator to handles Ll, which pressure assists the effective pressure in the cushion chamber in balancing the preponderating pressure which tends to move the motor forwardly in cylinder 3. wWhen the operator closes the throttle valve a second charge of fluid is admitted to the cushion chamber, as previously described, and the pressure therein operates to move motor A rearwardly as the pressure in the live air chamber escapes through the motor to the exhaust chamber and thence to atmosphere through ports 17, the rearward movement of the motor continuing until the ports 17 are closed ott by head l0 whereupon the motor comes to rest in the position shown in Fig. 1.

The working tool B is arranged to be retained in operative relation with percussive motor A without interfering with the movement of the motor in cylinder 3, the retaining means being connected to a rigid portion oi' the tool so that the operator can conveniently withdraw the tool and shift it to a new location. To secure a rigid connection and yet to permit the use o1Q a` retainer of minimum length, gland nut is provided with an enlarged extension 15a, which encloses and protects the projecting end ot motor A when the latter is in its retracted or inoperative position (Fig. 1). rlhe retainer is secured` to the extension 15a and in the present instance is in the form of a yoke 25, which cooperates with the collar on the shank of the working tool. Yoke 25 has inturned ends 25a extending into suitable sockets in entension 15a, this pivotal connection enabling the retainer to be swung to one side when the working tool B is to be removed or inserted in the Jtool. j

lll/'bile a preterred'form of the invention has been herein shown and described, it is to be understood that the invention is not limited to the specific details thereof, but covers all changes, modifications and adaptations within the scope ot the appended claims.

l claim as my invention:

1. A fluid pressure tool comprising a member providing an elongate chamber, a handle on said member for manually support-ing the latter, a tluid pressure percussive motor movable as a unit in said chamber, and means on said member and said motor cooperating to provide opposing pressure chambers and an intermediate exhaust chamber, and means for trapping pressure fluid in one of said pressure chambers.

2. A fluid pressure tool comprising a member providing an elongate chamber with an open end, a handle on said member for manually supporting the latter, means for restricting a portionv ot said chamber remote from said open end, and a percus-:sive motor movable as a unit in said chamber and having a part projecting through said open end and an extension in said restricted portion.

3. A fluid pressure tool comprising a member providing an elongate chamber open at one end and closed at the other, a handle on said member for manually supporting the latter, means for restricting a portion of said chamber adjacent the closed end of the saine, a percussive motor movable as a unit in said chamber and having a part projecting through said open end and an extension in said restricted portion, said extension serving as a conduit for supplying pressure liu'd to said motor.

il. A fluid pressure tool .comprising a cylinder member providing an elongate chammost part of'said chamber,said member liavslidably fitting said chamber beyond saidring, an extension on said motorrslidably fitting said bearing ring and pro]ecting with? 1n the rearmost part of saidchamber, said member havingvent ports controlled by said head and arranged on forward movement of said motor to connect the portion of the chamber between said head and said ring to atmosphere.

5. A fluid pressure toolcomprising acyl-V inder member providing an elongate chamber having a closed end, a fluid pressure Vinotor movable within'said chamber, cooperating means on said member and said motor vfor dividing said chamber into three parts which vary in size with themovement of said motor, said means including a bearing ring within said chamber in spaced relation to theclosed end thereof and a head on said motor slidably fitting said chamber beyond said head, an extension on said motor slidably fitting said bearing ring and projecting lwithinthe rearing vent ports controlled by said head and arranged on forward movement, of said mo'- torto connect the portion of the chamber be-v tween said head and said ring to atmosphere, said motor having a barrel extending beyond said cylinder member, packing and bearing means on saidV cylinder for said barrel defining a cushion chamber between the same and said head, and means for supplying a chargev of pressure fluid to said cushion chamber -to move said motor rearwardly or to resist its forward movement. y

6. A fluid pressure tool comprising' a cylinder member providing an elongate chamber, a fluid pressure motor movable within said chamber, cooperating means on said member and said motor for dividing said chamber into three parts, namely, a live air chamber, an exhaust chamber, and a cushion chamber, the relative sizes of said chambers being varied by the movement of said motor, means for admitting pressure fluid to said live air chamber and for conducting a portion thereof to said motor to operate Vthe latter, and means for supplying a charge of pressure fluid to said cushion chamber.

7. A fluid pressure tool comprisingl a handle member providing an elongate chamber, a fluid pressure percussive'motor mounted for sliding movement in said chamber, means for controlling the position of said motor within said chamber by pressure fluid including opposed areas on said motor, and

means operating automatically for directing a charge ofpressure fluid tofone ofsaid areas when the toolis started-and for shutting ofi1 further supplyjto said area while `thetool is in-operation.

f8; A fluidpressure tool comprising ahan-"i dle member-providing an elongateV chamber,

arfluid ypressure percussive motor mounted fori sliding movement in said chamber, means for controlling the position of said `motor within said chamber by pressure fluid includingopposed areason said motor, and means operating automatically to direct a charge of; pressure fluid to one of said areas only-.at the starting and stopping of'saidtool. i

9; Aifluid pressure tool comprising a han-` dle memberfproviding'an elongate chamber, a

fluid pressure percus'sive motor mounted` for Y slidingi movement in saidchamber' and havingvopp'osed areas, means for controlling the s position of said motor, and meansfor directing acharge ofpressure fluid to one of said areas when the pressure fluid is admitted to.`

saidA motor to provide a resilient cushion for said motor and' again,- when the supply i of pressure fluid is cut off, in order to move said motor to its rearmost position" within said member. 1 i l0. A liuid pressure tool comprising a mem-` ber providinglan elongate chamber, means for y controlling I the admission of pressure fluid'f to said chamber includinga throttleV valve, ajfluid pressure motor movablyinount-- ed in said chamber'and presenting a pressure area to the admitted motive `fluid and. pro viding an opposing pressure Varea of small eX- tent, and means operating automatically only when said valve is opened or closed for ad# mittingla 'charge of pressure liuid torsaid smaller area. Y i

11. A fluid pressure tool comprising a member providing an elongate chamber, means for controlling the admission of pressure fluid to said chamber includinga throttle valve, a fluid pressure motor movably mounted in s aid chamber and presenting a pressure area tothe admitted motive fluid and providing an opposing pressure area of small eX- tent, and meansy controlled by said throttle valve for admitting a charge of pressure fluid to said smaller area momentarily during the opening movement of said valve.

12. A fluid' pressure tool comprising a member providing an elongate chamber, means for controlling the admission of pressure fluid'to said chamber including a throtw tle valve, a fluid pressure motor movably mounted in said chamber and presenting a pressure area to YtheA admitted motive fluid and providing an opposing pressure area of smaller extent,` and means associated with said throttle valve for directing pressure fluid momentarily to said smaller area at the opening and closing of said valve.

13. A fluid pressure tool comprising a member providing an elongate chamber,

means for controlling the admission of pressure Huid to said chamber including a throttle valve, a fluid pressure motor movably mounted in said chamber and presenting a 5' pressure area to the admitted motive Huid and providing an opposing pressure area of smaller extent, and means for admitting a charge of pressure fluid to said smaller area. when said throttle valve is opened, said lastf lo Vnamed means comprising an extension on said valve and a passage in said member leading to said smaller area and controlled by said extension.

14. A fluid pressure tool comprising a member providing an elongate chamber,

means for controlling the admission of pressure fluid to said chamber including a throttle valve, a fluid pressure motor movably mounted in said chamber and presenting a pressure area to the admitted motive fluid and providing an opposing pressure area of smaller extent, and means associated With said throttle valve for directing pressure fluid momentarily to said smaller area at the opening and closing of said valve, said last-named means comprising a plunger having a reduced portion actuated b v said valve and a passage in said member leading to said smaller area, said passage receiving pressure fluid by the reduced portion of said plunger during the movement of the latter in either direction.

15. A fluid pressure tool comprising a cylinder member having a handle and providing an elongate chamber, a fluid pressure percus-sive motor movable Within said chamber and projecting therebeyond, packing, and bearing means on said member for the projecting portion of said motor including a gland nut, a Working tool extending Within said motor to receive the blows thereof, and means on said gland nut for retaining said Working tool in operative relation With said motor Without interfering With the movement of the latter in said member.

16. A fluid pressure tool comprising a cylinder member having a handle and providing an elongate chamber, a fluid pressure percussive motor movable Within said chamber and projecting therebeyond, packing and bearing means on' said member for the projecting portion of said motor including a gland nut, a Working tool extending Within said motor to receive the blows thereof, and a retainer lvolie on said gland nut for retaining said Working tool in operation relative to said motor Without interfering with the movement of the latter in said member.

Signed by me at Coscob, in the county of Fairfield and State of Connecticut, this 4th day of April, 1928.

WILLIAM H. BENEDICT.

BIE

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