Consolidated Pneumatic Tool Company Ld. v. Clark. 66 spring 76 and its mode of application to the lever in the present instance, "however, constitute a novel feature of my invention, which may now be "explained more in detail by reference to Figures 1 and 12. 66 66 66 "It is a desideratum in this art to produce a tool of the smallest size and 5 "most compact construction, and of the least weight, consistent with the "requisite strength and durability, and power and efficiency in operation; and particularly is it desirable to decrease the length of the tool to the minimum. "At the same time it is important that the piston shall have a considerable "length of stroke, in order that the pressure may have time to properly 10 "act upon it, in order that it may be properly cushioned at each end of "its stroke, and in order that it may strike the tool with a sharp elastic "momentum blow and rebound without shock. In many tools heretofore "devised decreased length of the tool has been attained at sacrifice of the "length of the stroke of the piston, so that the latter cannot be properly 15 "cushioned, has to be started at each end of its stroke by the sudden dead "action of the full pressure, and strikes the tool a solid, dead and unyielding "blow, with a consequent jarring of the whole tool and discomfort and injury "to the operator. In my tool the novel construction and arrangement of the parts which have been shown and described enable me to give the piston full 20 "length of stroke, with all its attendant advantages, without increasing the "length of the tool as a whole. The comparatively short piston, and the arrangement of the spring with one end surrounding the front end of the "piston and the other surrounding the inner end of the bushing and tool stock, "afford room for the long spring and accommodate the long stroke of the piston 25" without unduly increasing the length of the casing containing the piston "chamber; while the arrangement of the valve chamber transversely across the "rear end of the piston chamber and its attachment thereto by the head block fitting over and embracing the valve block, and the coupling sleeve surrounding "the valve block and screwed upon the head block and binding the parts 30" together, cause the valve mechanism to add but very little to the length of "the piston chamber, so that the whole of the tool proper is but little longer "than the casing containing said chamber. So, if the flexible "throttle valve becomes worn the tube may be readily removed from the "valve chamber by unscrewing the nipple 62 and plug 64, and a new tube be 35 put in its place. The fulcrum pin 70 of the lever 72 may be riveted in the "handle so that it cannot become loosened, and the lever be put in place "afterward, and be removed and replaced at will by removing the spring 76. "While the foregoing and other advantages are derived from the particular "construction and arrangement of the parts, yet other features of my invention are quite independent thereof and in no wise restricted thereto, and I do not "wish to be understood, by describing such construction and arrangement in "detail and setting forth their advantages, as intending to limit my invention "beyond the terms of my respective claims or the requirements of the prior "art." 66 40 " 45 66 66 There were 73 Claims, but only the following are material for this Report :"15. In a pneumatic tool, the combination of a piston-chamber, a piston "therein, a resetting spring for the piston, a valve-chamber having an inlet and an exhaust port and communicating with the rear end of the piston chamber "by a constantly open port or passage, and a valve in said valve-chamber, 50 operating to intermittently admit pressure to and exhaust it from said "chamber, substantially as described. 42. In a pneumatic tool, the combina"tion, with the tool proper, of a grasping handle secured thereto and having "the pressure supply duct extending through it, a throttle valve in the handle "for controlling said duct, and a lever confined in a recess in the handle for operating said valve and projecting outside the recess at one end into position "to be pressed by the hand of the operator, substantially as described. 43. In "a pneumatic tool, the combination, with the tool proper, of a grasping handle 55 66 66 66 66 a Consolidated Pneumatic Tool Company Ld. v. Clark. "secured thereto and having the pressure supply duct extending through it, throttle valve in the handle for controlling said duct, and a spring-pressed "lever pivoted in a recess in the handle for operating said valve and normally acting to close it, the lever projecting outside the recess at one end into "position to be pressed by the hand of the operator, substantially as described. 5 "44. In a pneumatic tool, the combination, with the pressure supply passage, "of a valve chamber formed therein, a flexible tube titted in said chamber, a "tubular locking plug or collar screwed into the valve-chamber at one end and "entering the flexible tube, to hold the latter in position, a sliding plunger "moving transversely of the chamber and adapted to collapse the tube to close 10 "the passage and a spring pressed lever for engaging said plunger for operating "the same and normally holding the plunger in position to close the valve, "substantially as described. 45. In a pneumatic tool, the combination, with "the pressure supply passage, of a valve chamber formed therein, a flexible "tube fitted in said chamber and provided with a peripheral flange abutting 15 "against an annular shoulder, a screw collar for clamping the flange against "said shoulder, and means for collapsing the tube in the chamber to close the "valve, substantially as described." On the 29th of October 1896 Letters Patent (No. 24,165** of 1896) were granted to Joseph Boyer for "Improvements in pneumatic hammers and valve 20 "mechanism therefor." The Complete Specification, as further amended in 1898 and so far as material for this Report, was as follows:-"My present invention relates to machines of "the general nature of that heretofore patented to me by Letters Patent No. "7,672, of April 16, 1895. The first and principal feature of my present inven- 25 "tion relates to the valve mechanism, by which the movements of the piston 5 15 66 66 66 66 66 66 66 Consolidated Pneumatic Tool Company Ld. v. Clark. are controlled. It is highly desirable, for purposes of convenience in handling "the tool when at work, that the bodies of tools of this character shall be made as short as can be done' consistently with the length of stroke which it is necessary to give the piston in order that the latter may act with sufficient power upon the chisel or other working tool employed with the hammer. "Inasmuch as the force of the blows delivered by the piston at any given "pressure of motive fluid depends mainly upon its weight and length of stroke, "it is desirable that it shall be heavy and that it shall have as long a stroke as possible. But it is also desirable that the body of the tool shall not be of 10 excessive diameter, and weight must therefore be added to the piston by increasing its length, rather than its diameter. Under these conditions, there"fore, it follows that increased power in the tool is to be attained chiefly by "increasing the length of the piston chamber, to accommodate long strokes of a long piston, and a piston chamber of maximum length consistent with "the length of the tool as a whole is therefore essential to improvement along "these lines. It is the principal object of the novel valve mechanism constituting the first feature of my present invention to accommodate a piston "chamber of increased length without increasing the length of the tool as a "whole, and to thereby permit a greater length of stroke of the piston in a tool 20" of given length, and consequently increase the power of action of tools of this "character. In the tool shown and described in my aforesaid patent, and in 66 many other tools of this character which have been patented and some of "which are in practical use, the valve has been arranged in a separate chamber "immediately in rear of the piston chamber, between the latter and the handle 25 or head of the tool, with the result that this interposition of the valve in a separate chamber at the rear end of the piston chamber and in line with the "latter has necessarily diminished the possible length of the piston chamber by "the amount of space occupied by the valve chamber and valve, and has conse"quently diminished to that extent the possible length to be given the stroke 30 "of the piston in any tool of given length. In the novel valve mechanism of my present tool the valve consists of a cylindrical shell arranged within the 66 piston chamber itself and of a sufficient internal diameter to surround the piston and permit it to pass entirely through the valve. This valve is preferably located in the rear end of the piston chamber, so that the piston passes 35 through and is surrounded by the valve at the end of its rearward stroke, as "illustrated in the drawing and hereafter described, but this particular location "of the valve is not essential to the broader scope of my invention, as will "be apparent from the description thereof hereinafter given, and from the "terms of my respective claims. It results from this construction and arrange"ment of the valve that the space occupied by it does not diminish the length "of the piston chamber at all, since the piston chamber extends entirely through "the valve, and it therefore follows that a tool of given length will accommo"date a piston chamber as much longer than the piston chambers of the prior "tools above referred to as the length of the space occupied by the valve 45" chamber and valve in such prior tools, thereby permitting greater length of "stroke for the piston and correspondingly increasing the force of its blows and "the power of action of the tool. 40 66 66 66 66 66 66 "Another feature of my present invention consists in a construction whereby "the inner end of the shank of the chisel or other working tool itself forms the 50 means for closing the front end of the piston chamber and constitutes a part of "the cylinder head or abutment against which the motive fluid admitted to the "front end of the piston chamber acts in driving the piston rearward. 66 "Another feature of the invention relates to a novel locking device for the "coupling sleeve which holds the parts of the tool together; all of which 55 features will be hereinafter more fully explained by reference to the accompanying drawings, in which Figure 1 is a longitudinal section of my new tool, "with part of the handle left in elevation, and with the piston at the forward 66 Consolidated Pneumatic Tool Company Ld. v. Clark. "end of its stroke and the valve in corresponding position; Figure 2 a view "corresponding to Figure 1, with the handle of the tool broken off, and with "the piston near the rear end of its stroke, and with the valve in corresponding "position; Figure 3 a perspective view of the valve itself; Figure 4 a vertical "section of the valve block and valve, with the valve in the position shown in 5 "Figure 1; Figure 5 a corresponding view with the valve in the position shown "in Figure 2; Figure 6 an elevation of the rear face of the valve block (the right hand face of the block shown in Figures 4 and 5) . and 66 Figure 10 a sectional detail of a modification. Of the several views "Figures 3 to 8 correspond in size to the tool from which the drawing was 10 "made, while Figures 1 and 2 are approximately two-third such size. The same letters of reference are employed to represent corresponding parts in "all the views. 66 66 66 66 "The cylinder or barrel A of the tooth is provided at its rear end with an "annular flange B over which fits a coupling sleeve C provided at its front end 15 "with an internal flange abutting against the flange B on the cylinder, and externally threaded upon its rear portion to screw into the interiorly threaded "cap D projecting from the cylinder head or handle base E, such head or base having the grasping handle F of the tool formed integral with it. The supply "duct G for the motive fluid extends through the handle F and is controlled by 20 "a throttle valve operated by a thumb lever H, as in my aforesaid patent. "Located within the cap D and rear end of the coupling sleeve C, and clamped "by them between the rear end of the cylinder A and the head E, is the cylin"drical valve block I hereinafter more particularly described. Suitable dowel pins interposed between the rear end of the cylinder A and forward side of 25 "the valve block I, and between the rear side of the valve block and the "cylinder head or handle base E, hold the cylinder, valve block, and head E in "position and prevent turning of them relatively to each other. The novel "lock which co-operates with the coupling sleeve to prevent unscrewing of the "latter will be hereafter described. The portion of the piston chamber 30 "within the cylinder A consists of a straight cylindrical bore whose rear end 66 opens at its full diameter through the rear end of the cylinder A, and whose "front end is partially closed by the annular shoulder or ring J let within the "cylinder A. The extreme forward end of the cylinder A is in the present "instance bored out to the same diameter as the piston chamber, and has driven 35 "into it, so as to be held in fixed position therein, a chisel sleeve or bushing K. "The rounded rear end of the shank of the chisel or other working tool L "extends through the sleeve or bushing K, and in the present instance through "the ring J to a point about flush with the rear face of the latter. "The piston M consists of a solid cylindrical piece of steel fitting the bore 40 "within the cylinder A, and in the present instance provided with a circum"forential groove M1 near its rear end, and also having formed upon its front "end (for a purpose hereafter explained) a short projecting stem N which "contacts with the rear end of the shank of the tool L when the piston "reaches the forward end of its stroke. 45 "The valve O, Figure 5, consists of a very thin steel shell, which is circular "in cross-section at all points in its length, but of irregular shape in longitudinal "section, and the passage through which is at its smallest diameter somewhat "larger than the piston M. Near its left hand or forward end the valve O is "provided upon its exterior with a circumferential groove a, while immediately 50 "at the right or rear of its middle line it is formed into an outwardly projecting "hollow flange or ring b whose left hand or forward face forms an annular 66 pressure area c against which the motive fluid acts to move the valve rearward or to the right in the manner hereinafter explained. Near its right hand or 66 "rear end the valve is formed with an annular shoulder or pressure area d, 55 against which the motive fluid acts to force the valve forward, as hereafter "explained. 66 Consolidated Pneumatic Tool Company Ld. v. Clark. "The valve O fits within the valve block I, which latter is composed of two "parts, a main portion or body I, and a flanged ring or disk I fitting against "the rear face of the block I. The left hand or forward half of the block I is "bored out to a given diameter corresponding to the external diameter of the 5 "left hand or forward half of the valve O, while the right hand rear half of "the block I is bored out to a larger diameter corresponding to the external "diameter of the projecting ring b of the valve. A circular flange or ring I projecting from the left hand forward face of the ring I' enters and snugly "fits within the rear end of this larger bore of the block I, leaving a space 10"between the forward side of said flange and the annular shoulder at the "forward end of the larger bore of the block I, within which space the pro"jecting ring b of the valve fits and travels back and forth as the valve is "moved in one direction or the other. The surface ƒ of the valve, between the "ring b and the pressure area d, Figure 3, snugly fits within the flange I of 15" the ring I', Figures 3 and 4, while the surface G at the rear end of the valve snugly fits within the circular opening in the ring I when the valve is in right hand rearward position, as in Figures 1 and 4. 66 66 "When the valve is in rearward position, Figures 1 and 4 there is an annular space or chamber e between the pressure area c of the valve and the front 20 "side of the inner edge of the ring I'. The former may be called, for con"venience of description, the space or chamber in front of the valve, and the "latter the space in rear of the same. When the motive fluid is admitted to "the space el it will act upon the area d of the valve and will force the latter "forward if there is no motive fluid in the space e acting upon the larger area d 25" of the valve. When the motive fluid is admitted to the space e the pressure against the front of the valve will overcome that against the rear, and force "the valve rearward. 66 66 "The larger bore of the block I is provided about midway of its length with an internal circumferential groove h which communicates by a series of 30 "radial ports i with an annular open space j around the valve block immediately "in rear of the right hand rear end of the coupling sleeve C, Figures 1 and 2, "and this space j opens to the outer atmosphere through a series of holes k in "the lower side of the threaded cap D which screws over the coupling "sleeve C. The groove h is therefore an exhaust passage constantly open to 35 "the atmosphere. The ring b is provided with a series of slots which when "the valve is in right hand rear position register with the groove h and thereby "place the interior of the valve in communication with the exhaust. When "the valve is moved forward (to the left) the slots are carried away from the groove h and the communication between the interior of the valve and the "exhaust cut off. 40 66 45 66 66 "The smaller bore of the valve block I is provided with two internal circum"ferential grooves m, n, for a purpose hereafter explained, the groove m being "considerably deeper than the groove n. When the valve is in forward left "hand position these two grooves are put into communication with each other by the circumferential groove a upon the exterior of the valve. The rear groove n communicates by a passage o with the exhaust port i, so that said groove n is always open to the exhaust, and when it is placed in communica"tion with the groove m by the groove a of the valve the groove m will then "likewise be open to the exhaust. For the purpose of furnishing freer com50 munication between the groove n and the exhaust there are preferably several passages o connecting said grooves with different ports i. 66 66 66 "A passage opening into the piston chamber at P, Figures 1 and 2, leads rear"ward through the wall of the cylinder and through the wall of the valve "block I and opens into the annular space e in front of the pressure area c of 55" the valve, Figures 4 and 5. A second passage opening into the piston chamber "at Q leads rearward through the wall of the cylinder and wall of the valve "block I and opens by a radial port into the groove n in the valve block, as |