US2668518A - Pneumatic impact tool - Google Patents

Description

Feb. 9; 1954 C. E. WHITE PNEUMATIC IMPACT TOOL 2 Sheets-Sheet 1 Filed Dec. 8, 1952 C- E. WHITE PNEUMATIC IMPACT TOOL.

Feb. 9, 1954 2 Sheets-Sheet 2 Filed Dec. 8, 1952 ms Milg INVENTOIT.

; i Z" a iEATTORNEY Patented Feb. 9, 1954 UNITED STATES PATENT OFFICE 7 2,668,518 PNEUMATIC IMPACT TOOL Clifford E. White, Belton, Tex.

Application December 8, 1952, Serial No. 324,787

7 8 Claims. 1

This invention relates to a pneumatic type impact tool of extremely simple construction adapted to be manually supported in one hand and controlled by a gripping action of the hand which supports the tool for admitting air under pressure to a plunger element whereby a driving force is imparted to an impact head, constituting an end of the tool.

Still another object of the invention is to provide a novel pneumatic type impact tool whereby a series of impact blows may be imparted by the tool in rapid succession and automatically by merely maintaining a manually controlled part in an open or operative position.

Another object of the invention is to provide a portable pneumatic type impact tool which may be readily attached to any suitable source of air under pressure and which is adapted to detachably support various heads or bits to be operated by the tool for accomplishing various types of work.

Still another object of the invention is to provide an impact tool which is capable of supporting a bit or impact head in various positions relatively to the axis of the tool and so that the impact force imparted to the head of bit may be along a line axially of the tool or at various angles to the axis of the tool, to adapt the tool for use in confined spaces, as .for. 'example between metal panels of a vehicle body or inother locations where a straight thrust may not be imparted to a tool head or bit.

Various other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawings, illustrating a presently preferred embodiment thereof, and wherein:

Figure 1 is a side elevational view of the pneumatic impact tool;

Figure 2 is an enlarged longitudinal sectional view taken substantially along a plane as indi-' cated by the line 2--2 of Figure 1; V

Figure 3 is an enlarged longitudinal sectional view taken substantially along a plane as indicated by the line 33 of Figure 2; 7

Figures 4 and 5 are enlarged crosssectional views of the tool taken substantiallyalong planes as indicated by the lines 4-4 and 5-5, respectively of Figure 3; Figure 6 is a plan view of one element of the tool; 7 I

Figure '7 is a plan view of one formof de-, tachable head, shown partly in section, for use with the impact tool;

Figure 8 is a side elevational view of form of impact head or bit;

another Figure 9 is a plan view of another form of of, as indicated at I6 in Figures 2 and 3. Ad

jacent inner ends of the sections I4 and I5 are connected by an externally threaded coupling disk I! onto which the inner ends of the sections I4 and I5 are threaded, as clearly ilustrated in Figures 2 and 3. The opposite, outer end of the sleeve section I5, constituting the rear end of the barrel I2 is closed by an externally threaded disk I8, constituting the rear end wall of the barrel I2. The disk I8 has a threaded opening I9 extending therethrough and forming the inlet of the tool I2 into which is threaded the outlet nipple 25 of a suitable air hose or conduit fitting 2| which is adapted to be connected to any suitable source of air under pressure as by means of an air hose, not shown, an outlet end of which is attached to the opposite, inlet end 22 of the fitting 2|.

An externally threaded relatively thick disk forming a partition 23 is threaded into the inner end of the sleeve section I5, before said sections are connected by the coupling disk I1 and is positioned approximately intermediate of the ends of the sleeve section i5. An externally threaded washer or ring 24 is threaded into the inner end of the sleeve member I5 and against a side of the partition member 23 and functions as a lock nut to retain said partition member in an adjusted position. The partition member 23 combines with the end wall I8 to form an air chamber 25 therebetween and within the sleeve section I5. The sides of the partition member 23 and the washer 24 which face toward the inner end of the sleeve section I5, are provided with circumferentially or diametrically. spaced recesses 26 for receiving a suitable turning tool to apply said parts to or remove said parts from the sleeve section I5. The partition 23 is provided with two spaced passages 21 extending therethrough and is also provided with a tapered bore 28 located between thepassages 21 and which tapers toward the chamber 25 for loosely receiving therein a stem 29 of a disk-like valve 30 which is disposed in the air chamber 25 and 3 which normally closes the ends of the passages 21 which open into the chamber 25.

A stuil'lng box 3! is detachably mounted in the sleeve section 15 between its inner end and the washer 24 and an actuating rod 32 extends slidably through the stuffing box 3] and radially into the sleeve i between the partition wall 23 and the coupling IT. The inner end of the rod 32 is pivotally connected at 33 to th end of thevalve stem 29 which is located remote to the valve 33. An expansion spring 34 is disposed on the valve stem 29 and bears against the partition 23 and rod 32 to maintain the valve. 30 seated against the partition wall 23 to close the passage 2'1. An expansion spring 35 is mounted on the outer end of the rod 32: between the stufing box 3! and a spring stop 36 which extends transversely from. the rod 32, for urging the rod outwardl of the sleeve section I5 to position the stem 29 against the straight portion of the bore 28 so that the valve 30-Wl11 seat flush. against the side of the partition 23. A resilient handle 31 is disposed longitudinally of the sleeve section l5 and has. one end thereof secured by a fastening 38 to the rear end of the sleeve section. The resilient handle 31 extends forwardly from its secured end in diverging relationship to the sleeve section. The handl 31 has a concave underside into which. the outer end of the rod 32 extends and against which the rod. bears. adjacent the free end ofv the handle. The handle 31 is spring biased away from the sleeve section. [5 but when gripped with the sleeve section may bee-displaced toward the sleeve section by a gripping action to displace the rod 32 inwardly of the. sleeve section torock the stem 29 and valve. 30 clockwise. as, seen in Figure 3, so that they upper. edge, portion of the valve 35 will fulcrum on the partition 23 to expose the passages 21 so that, air; may escap therethrough from the chamber tothe air chamber 39. of the sleeve section I5 and which. is located between the partition 23. and the coupling ll. When the gripping pressure is released from the handle 3'! the spring 35will displace the rod 32 outwardly and the spring. 34; will return the valve to its closed position of Figure 3 against the partition 23 to close the. air, passages 21 between the air chambers Hand 39.

The coupling disk I? is provided with a bore 48 having a flared, end 41. opening into the air chamber 39. and forming a valveseat. The bore 40. at. its. opposite. end. is provided with a plurality of restricted passages 42 which open into the cylinder section l4 and which surround. a larger central opening 4.3 which forms. a guide for a valve stem. 44 which projects from. a valve 45 loosely through the bore M1 and. slidably through the opening or bore portion. 43-. Said valve 45 isv disposed in the. chamber 3.8 and seats in the valve seat M. for closing the bore 4H. An expansion coil spring 45 is. disposed on thepopposite and of the valve. stem within the cylinder section 14 and bears with one end. against the coupling disk l! and has its opposite end hearing against a spring stop 41 which projects laterally from and is anchored to the valve stem 44.

A piston is is slidably disposed in the cylinder section I l between the coupling member I1 and an externally threaded disk 69', which disk 39 threadedly engages in the outer internally threaded end It of thecylinder section [4 and forms the front wall of the tool barrel or body is. The piston 4.2 has a close fitting sliding engagement in the cylinder section [4 and combines with the coupling disk I! to form an expansion chamber 58 therebetween and within the cylinder section It. Thus, the coupling disk I! forms a second partition separating the intermediate chamber 39 from the expansion chamber- 55. A stem 5! is fixed to and projects perpendicularly from the piston 8 and toward the valve stem M. The front wall disk 49 is provided on its outer side with. a. threaded boss 52 and said disk 43 has a central bore extending therethi'ough and through said boss, designated 53. A piston rod 54 extends from the opposite side of' the piston or plunger c3 and slidably through the bore53 and has an expansion coil spring 55 disposed thereon and bearing with one end against the front wall %9 and with its opposite end against the piston or plunger 48. The spring 55 is stronger than the spring 55 and therefore normally displaces the plunger or piston 48 to its position of Figures 2 and 3 and in which the stem 5i bears against th valv stem 44 to compress. the spring 46; and hold the valve in an open, position. A forward chamber 56 of the cylinder section. H2, in which the spring is disposed and which is located between the piston or plunger 48 and end wall 59-, is provided with vent ports 51 spaced a substantial distance from the front wall 53 and also from thenormal position of the piston or plunger 48, as illustrated in Figures 2 and 3. The front wall 49 is provided with a plurality of vent ports 58 for venting. the front chamber 56- whenthe vent ports 5'! are closed by the plunger 48 or are in communication with the expansion chamber 50.

A guide sleeve 59 extends through an opening 60 in an end wall 6| of a cap-like coupling nut 62:, the opposite end of which is externally threaded as seen at 63 to engage the boss 52. The guide sleeve 59 has a flanged end 34 which abuts against the inner side of the wall Bl around the opening 65 to retain an end of the sleeve 59 in engagement with, the nut 62, by which said sleeve is supported as an extension of the boss 52. Likewise, the bore of the sleeve 53 is of: the same diameter'as and registers with the bore 53-. A tool. supporting rod 65 is reciprocably disposed in. the guide sleeve 59 and projects from the. outer opposite end of said sleeve. The rod 65 has. an. elongated slot 66 adjacent its irmer end through which extends the shank of a bolt and nut fastening 61 which extends diametrically through the sleeve. 59, near the outer end thereof and which is normally disposed adjacent the. outer end of the slot 66', as seen in Figure 2; A contractile. coil spring- 68 is wound about a portion of the rod 65 beyond the outer end of the sleeve 59 and is anchored to the rod by a fastening 69 at one end thereof. The opposite end of the spring 68 is secured to the fastening 6?. The distal end of the rod 65, beyond the fastenings 69, is threaded as seen at 'm to threadedly engage in an internally threaded socket; H of an impact head 12. A jamb nut 13 is preferably threaded on the rod end Hi and is placedagainst the socket end H to retain the impact head 72 man applied position. The impact head I2 as illustrated in Figure 1 isintended for straightening small dents in metal and it will be obvious that impact heads of various sizes and shapes may be interchangeably employed on the tool supporting rod 55; Likewise, other suitable tools may be utilized, each of which is provided with an inner enddefined by an internally threaded socket, corresponding to the socket H, as for example a riveting head in Figure 8, and a paint chipping blade 16 having;

a socket No, as illustrated in Figure 9.

The guide sleeve 59' and'rod 65 are-shown as being straight in Figures 1 and 2. However, for working in closeplaces a curved guide sleeve 59a and a curved tool supporting rod 65a may be substituted for the sleeve 59 and rod'65, as i11ustrated in Figure 10. Obviously, the extent that the parts 59a and ,65a are curved may be varied from substantially the maximumas illustrated in Figure 10 to only a slight curve." It will be obvious that the tool [2 with the parts 59a and 65a substituted for the parts 59 and65 may-be utilized' in close places where the straight parts of Figure 1 could not be employed, as for'example, between metal panels where the available space was limited orbetween metal parts and other adjacent members as frequently occur for example in automobile bodies where considerable difficulty is encountered in straightening dents because of the lack of available space when striking an impact blow against an indentation. As the other parts as disclosed in Figure 10 correspond to the parts as illustrated in Figures 1 and 2 and previously described, a further description thereof is considered unnecessary.

Assuming that the impact tool 12 is assembled as illustrated in Figures 1 and 2 and that the fitting end 22 is connected to a source of air under pressure as by being attached to a suitable hose or conduit, not shown, air from the source of supply under pressure will pass through the fitting 21 into the rear'chamber 25. When it is desired to operate the tool l2, the hand of the operator which grasps the sleeve portion 45 for supporting the tool is operated by a gripping action to displace the handle 31 toward the sleeve I to thus displace the rod 32 inwardly of the sleeve, as previously described, to rock the valve 39 to an open position so that the air under pressuremay' enter the intermediate air chamber 39 throughthe passages 21. As the valve 45 will then be held in an open position by the spring 55, the compressed air will flow from the intermediate chamber 39 into the expansion chamber 50 through the bore 40' and its passages 42, and when a suflicient air pressure has been built up the expansion chamber 50, which will occur almost instantly, the piston or plunger 48 will be displaced forcibly toward the front wall 49 thus driving the plunger rod 54 forcibly into the sleeve 59 to project the tool supporting rod 65 forcibly in a direction outwardly of the sleeve 59 or from left to right as seen in- Figures 1 and 2, thus imparting a sudden impact or power stroke to the impact head, blade or bit mounted on the rod end 10. As the plunger or piston 48 moves from left to right (Figures 1 and 2 and Figures 2 and 3) the stem 5| disengages the valve stem 44 so that the spring 46 moves the valve 45 to a closed position to prevent additional air passing to the expansion chamber 55 from the intermediate chamber 39. As the plunger rod 54 completes its impact stroke the piston 48 will have moved toward the front wall 49 past the vent ports 51 allowing the air in the expansion chamber 50 to escape through said vent ports 51 to the atmosphere. The vent ports 58 vent the forward chamber 56 after the piston 48 has closed the vent ports 5'! to the chamber 56 and additionally admit air to the chamber 56 during the return stroke of the piston 48 and until the vent ports 51 are again in communication 6. with the chamber 56. This left to right move-' ment of the piston 48 also loads the spring 55, so that when the air pressure is released from the expanded chamber 50 through the vent ports 51, the loaded spring 55 will forcibly return the parts 48 and 54 from right to left back-to their intermediate chamber 39 so that when the stem 5| strikes the valve stem 44 to displace the valve 45- from right to left to an open position, the. compressed air will rush through the bore 40- and-passages 42 into the chamber 50 to cause the piston 48 and piston rod 54 torepeatthe operation just previously described, and this operation will continue to be repeated so longvas the valve 39 is manually maintained in an open position by gripping action on the handle 31. Likewise, after the tool supporting rod 65 has been projected by impact of the plunger rod 54 with the inner end thereof and said plunger rod has commenced its backward movement from right to left with the plunger 48, the contractile spring 68 will return the supporting rod 65 to its position of Figure 2 before the plungerrod 54 has again been projected outwardly of the front wall 49. I

It will thus be apparent that a tool of extremely simple construction has been provided capable of being operated by compressed air and wherein repeated impact or power strokes may be accomplished in rapid succession by a mere gripping action of the operator on the tool. It will also be apparent that the fastening 61 and slot 66 cooperate to prevent the rod 65 turning in the sleeve 59 to thus maintain the impact head, tool blade or bit nonrotatable relatively to the barrel I3 and in a proper position for the work to be performed thereby.

Various modifications and changes are contemplated and may obviously be resorted to, without departing from the spirit or scope of the invention as hereinafter defined by the appended claims. 7

-I claim as-my invention: a

1. A pneumatic tool of the character described comprising an elongated hollow handle'having a forward end and a rear end, a partition disposed in the hollow handle and spaced from the forward end thereof, a piston reciprocably mounted in the hollow handlebetween said partition and its forward end, a piston rod extending frornsaid piston through the forward end of the handle, spring means urging the piston toward said partition, a normally closed valve mounted in said partition and closing a passage therethrough opening into an expansion chamber defined by the space between the piston and partition, a portion of said hollow handle between said partition and its rear end being adapted to be supplied with air under pressure through said rear end of the handle, means carried by said piston for engaging and displacing the valve to an open position as the piston approaches said partition for admitting air under pressure to the expansion chamber for displacing the piston and piston rod toward the forward end of the handle, said handle having vent ports therein opening to the atmosphere and located between said forward end and said partition and past which the piston travels in its forward movement whereby said expansion chamber is vented to the atmosphere as the ciston approaches the forward end of the handle and the spring means thereof is loaded so that said spring means will propel the piston and piston -rod rearwardly toward *said partition; said valve resuming --a-closed position as the :piston is moved away from said partition and being re-opened as the piston returns to a position adjacent the partition, and an impact receiving means supported by the handle including a tool head reciprocably supported beyond 'the forward end of thehandlaand-a part-supportingthe tool head and reciprocably mounted relatively to the handle and disposed to be engaged and forcibly projeeted'bythe piston rod on-the forwardstroke of the piston.

'2. A pneumatic tool in claim 1, asecond partition -member disposed in the handle between its rear end and saiddirst mentioned partition and combining therewith to form an intermediate air chamber between -'said partitions and a rearair chamber between the second partition and the rear end-ofthehandle and to which rear air chamber air under pressure is initiallyadmitted,-said second partition having a manually actuated normally closed valve controlling -a passage thereof for admitting air to said intermediate air-chamber when said manually-actuated valveis displaced to an-open position toeffect operation of thei-mpact tool.

3. A pneumatic impact tool i in claim 52-, a front wall -member adjustably mounted in the handle and formingthe forward end thereofhaving-a'bore'extending therethrough and forming a -guide for-reciproeably receiving the piston rod, said-- front wall having an external boss surrounding a portion of the piston rod and on which a stationary-part of the impact receiving means is detachablymounted; said stationarypart of the impact receiving meansincluding a guide sleeve disposed in alignment with said front wall bore and into which the piston rod is forcibly projected, and said first mentioned part of the impact receiving means comprisinga rod reciprocably disposed in saidguide sleeve and extending outwardly therefrom and having an inner end disposed to be struck by the; piston rod as the piston rod is moved to a projected position.

4. A pneumatic impact tool as in claim- 3, said front wall member and said first mentioned partition being longitudinally adjustable in the hantile for varying the stroke of the: piston.

v 5. 'A pneumatic impact tool of the character described comprising an elongated hollow handle having a forward end and a rear end, spaced par titions-mounted in said handle and dividing the handleinto longitudinally s'pacedchambers, said partitions including a-front partition and a rear partition each having passages extending theremiodgn'noimany closed valves mounted in said partitions --for normally closing the passages thereof, a piston reciprocably-disposed; in the handle between its forward end and said front partition, spring meansurging'the piston toward the frontpartition :andinto engagement with the valve thereof for displacing said front partition valve to an open position, a-piston rod extending from the piston through the 'forward end of said; handle; impact receiving ineans supported on the forward end ofthe-handle-:includinga reciprocably mounted tool carryingelement-having-an inner end disposed to be forcibly engaged by the piston rod when projected 'by movement of the piston ;forwardly of the handle, said front partition valve assuming a closed; position as the piston moves away from the "front partition. means for ventingthe chamber between the front partition and piston as the piston -approaches'a fully projected position, and manually actuated means for opening the valve of the rearpartition for admitting air under-pressure to'the chamber between saidpartitions.

6. A pneumatic impact tool as'in claim 5, and spring meansfor displacing said tool carrying element oi the impaotreceiving means to aretraoted position to be forcibly struck by saidlpi'ston rod when the piston is projected.

7. A- pneumatic impact tool as in' claim 5,;sam handle being for-me'd-ot end sections, said front partition formingacoupling member nineteenably coupling adjacent innerends QfpaidliaHdIe sections. a

8. A pneumatic impact tool as in claim"5,"tlie valve of said rearpartitionb'eing displaceableto an open position by a rocliin'g'moveffient, an'actuating rod connected to a stem of said rearpartition valve and extending ra'diallyffoin the-pandle, and a handle member disposed enemanytr the handle and engaging said actuating rod whereby a gripping aetion on the-tool handle and actuating handle will rock therear partit on valve to an openposition, materials-member and actuating rod forming said manually actuated means.

'cLiFF'oRD WHITE.

References Cited iii the 'file or this patent EDsTA rEsPAi ENTs Nu ber mate 134,083 1 --Dec. l7, 1M2 9632;688 June- 2B, 1910 130461175 Gross '-i- Dec. 10,1912

FOREIGN PATENTS Number ('Jountry -Date "220,096 Switzerland is 2.: June 16,1942

Images