US994743A - Power-operated percussive tool. - Google Patents

Description

0. H. HAESELER.

POWER OPERATED PERGUSSIVE TOOL. APPLICATION FILED AUG. 20, 1910.

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Patnted Jun 13,1911.

O. H. HABSELER.

POWER OPERATED PERGUSSIVE TOOL.

APPLIUATION FILED AUG. 20, 1910 Patented June 13, 1911.

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[VITA/E585 4 G. H. HABSELER. POWER OPERATED PERGUSSIVE TOOL.

APPLIGATION FILED AUG. 20, 1910. 994,743. Patented June 13,1911.

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CHARLES HERMAN HAESELER, 01 PHILADELPHIA, PENNSYLVANIA.

POWER-OPERATED PER'GUSSIVE. T8014,

Specification of Letter-s Patent.

App i n fil d A gu 20, 1910- sexiai 172- 578,149.

To all whom it may concern:

Be it known that I, CI-IARLEs H. Hansnnnn,

a cltizen .of the United States of America, and a resident of Philadel his, county of Philadelphia, and State oi have invented certain new and useful Improvements in Power-Operated Percussive 001s, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof. 7 ,This i vention relates to power operated porcussiv tools such as rock drills, mining machines; power hammers pile drivers and the, like, the operation of w ich'is effected by elfistic motive fluid under pressure alternatoly ndmitted into a cylinder upon oppo site sides of a piston freely mounted therein. Bsjceusc of the fact that in this class of tool the percussion piston is freely mounted in the cylinder, in the sense that there is no mtdhanical means to limit the extent of the stroke thereof, it follows that some means must be provided to prevent the iston from sttiking the upper head of the cy inder upon the upward or'return inovcmcntof, the piston. For this purpose it is common to ad mit the motive fluid behind the percussion piston at some period during its rearward movement, priorto the completions thereof, so that thisnmtim fluid s further compressed during the completion of such return movement and as so further compressed will act as a cushion, but in practice this method has usually been found ineflicicnt for several reasons: First, it is quite difiicult to maintain a tight enough joint for the purpose between the percussion piston and the cylin' der in which it is mounted, this being chiefly owing to the severe wear to which the parts are sulgjccted in use; second, it is manifestly impra icable to admit the motive fluid behind the piston at too early aperiod, because the .efl'oct would be to undesirably shorten the strokeof the piston, yet the rebound of the piston, iollowin a blow, varies considerably andv a point 0 admission sufiicient under some conditionsis wholl "inadequate under others; third, because 0 the comparatively small portion of the stroke that can be used for cushioning purposes there is too short a period for the pressure to accumulate sufiiciently, Again in the case of rock drills, to which th1s invention is particularly adapted, the presence of the rotator bar employed therein at the upper end of the cylinder, and which commonly enters a cavity in the percussion piston, reduces the available area not Pennsylvania,

for power s eed and only for cushioning purposes, but also for power purposes; moreover its presence results in further joints through which further of the tool by increasing the speed of operation thereof, whereby the force of the'blows are augmented, and the number of the blows imparted in a given period of time is in creased. These objects are attained by the employment of a special cushioning piston of smaller efiective area than that of the percussion piston, secured to a longitudinally fixed bar or rod, such bar or rod in the case of a rock drill or similar tool being conveniently the rotator or rifle barthereof, the said cushionin iston being'inounted in a cylinder provided in or carried by the per.- cussion piston, and the revision of means by which the motive fluid is admitted to the said cylinder in front of the cushioning piston during the forward movement of the percussion piston, and is held entrapped therein during the entire return movement of the percussion piston so that it will be compressed in such return movement to a high degree. The fluid thus com ressed forms an eflicient cushioningmeans, tehigh degree of compression attamed by reason of the length of stroke hein found Suflicient for all purposes, yet the act that the pres sure therein rises slowly until near the end of {he stroke, causing the percussion piston to ma e substantiallya oil and complete stroke under all conditiofisT llhe motfie fluid thus compressed reacts upon the next-forward stroke to augment the motive fluid admitted urposes, so as to increase the orce of the forward or power sti oke, thereby increasing the efficiency of thetdrill to a considerable extent. A further advdntage of the high degree of compressionuthus attained is the heating of the motive fluid. Not only is its tension increased, but where steam is employed as such motive fluid, the super-heating immediately obviates any tendency toward condensation thereoi, and prevents water from collecting ing cold weather, with almost no attempt at heat insulation of the connecting pipes.

The cushioning means just described may be used either supplementary to the common expedient of admitting motive fluid at the rear of' the percussion piston during its return movement as first above. described, or instead thereof. Preferably the motive fluid will still be admitted behind the percussion piston before the completion of the return movement thereof, but at a somewhat later period, this being for the doublepurpose of increasing thecushioning action at the extreme end of the stroke, and the buildi d'et'ail certain embodiments thereof, having beingcarried by and extending downward through the said reference to the accompanying drawings illustrating the same, and will then point out the novel features in claims.

In the drawings: Figure 1 is a view in partly side elevation and partly central longitudinal section, of a power rock drill constructed in accordance with my invention. Fig. 2 is a view in central longitudinal section of the central portion of the drill, showing the.main piston in its forward position.

Fig. 3 is a detail view partly in side elevation andpartly in central longitudinal section of the rifle bar employed in the con struction of tool illustrated in Figs. 1 and 2. Fig. 4 is a view in transverse section there'- through uponthe line 44 in Fig. 3. Fig. 5 is a detail view in central longitudinal section through the cushioning piston. Fig. 6

is a view 1n transverse section through the drill upon the line 6--6 in Fig. 1. Fig. 7 is a view in central longitudinal section through a pulsator type of drill equipped with my invention. Fig. 8 is an enlarged view in central longitudinal section through the main cylinder and correlated parts, the inaln piston being shown in its forward posi- 1on.' The rock drill illustrated in Figs. 1 to 6 inclusive comprises in general a main cylinder 35, a reciprocating percussionpiston 14 therein, a distributing valve 36 for admitting and exhausting motive fluid to and from the cylinder below and above the piston, an d a rocker 37, actuated by the piston n its reciprocating movements, for operating the valve. The upper end of the piston 14 is provided with a nut 15 which is fitted to. a rifled rotator bar 1,. the said'bar the upper head of the drill nut into acylindrical cavity 13 in the piston. At its upper end the riflebar isnflfififld with a ratchet wheel, the teeth of which are arranged to engagepawls in the said upper head, and by which rotational movements of the rifle bar are permitted in one direction only. As so far described the drill is-of ordinary well knownconstruction and opera'tes in the usual manner, elastic motive fluid such as steam or air under pressure being alternately admitted by the valve above and below the piston 14 to successively drive the piston downward in a power stroke and lift it in a return stroke. The rifle bar and its connections constitute a rotating means by which the piston will be given a partial movement of rotation when moving in one direction, the rifle bar itself being permitted to rotate by reason-of the ratchet and pawl mechanism whenthe piston is moving in the other direction. By this means an intermittent step by step' movement in the same direction is constantly imparted to the piston in its operation. The lower end of the rifle bar 1 is provided with a conical-extremity 5 to which is fitted the correspondingly conical portion 6 of a cushioning pis ton 7, the periphery of which is provided with packing rings 8 arranged to accurately fit the cylindrical. cavity 13. The piston 7 is hollow and is provided interiorly with a check valve 9, fitted to a valve seat 10, the said check valve being conveniently closed by means of a spring 11, a plug 12 constituting an abutment for thespring and serving as means to retain the valve against accidental displacement. The rifle bar 1 has a longitudinal passage which opens into the hollow piston 7 at its lower end 4 and con nects at its upper end, through a cross passage 3, with t-he interior of the cylinder 13 above the percussion piston 14. Motive fluid admitted above the percussion piston 14 to movement-of the percussion piston 14 in a return stroke the check valve 9 will automatically close, and the motive fluid in the 'cylindrical cavity v13 will be entrapped.

This fluid, which it will be realized is initially under the normal degree of compression at which the motive fluid is employed,

will be compressed further to a very high degree in thesaid' return movement of the percussion piston, the effect of which will be first-, to prevent the pistonl t from striking the upper head, second, to produce a powerful initial impulseto start the piston downward upon -a new'power stroke, and third, to augment the power of the tool in such power stroke. The netresult is a remarksaid cushioning piston 7. Upon the upward able increase of efliciency of the tool, and the avoidance of injury such as so commonly occurs from the piston striking the upper head.

mitted to thecylind'er 16 through an admis- I head 29, as will be well understood, thesesion port 18 and a passage 17, and the extent to which the air is compressed may be regulated by means of a hand operated regulator valve 18' in the lower end of the cyliuder 16 beneath the piston 32. The percussion piston 28 is located in a cylinder 19 which inothis instance is formed as a continuation of the cylinder 16, being divided therefrom by a'horizontal wall having passages 22 'therethrough which connect the two said cylinders. The rifle bar 25 in this construction is permanently fixed to the said wall,the nut 30 therefor being rotatably mounted in the pencussion piston 28 and having the usual or any desired form of ratchet and pawl connection with the piston as will be well understood, the said nut bein mounted in a counterhore in'the percusslon piston 28 and retained in position by'the usual form of slip release spring and arts being common in the art and requirmg no detailed description or illustration herein. Under normal conditions the nut is held against relative rotation with respect to the piston when the piston is moving in one direction so that the piston will be given :1 partial movement of rotation during such movement, but upon the movement of the -piston in the other direction the ratchet and pawl connection will release the nut and ,ermit it to rotate-freely in the piston. The

ower end of the rifle bar enters a cyline drical cavity 27 in' the piston28, and a cushioning piston 20 is accurately fitted to p the said cylindrical cavity 27 exactly as in the construction of Figs. l to Ginclusive, the said piston being similarly secured to the lower extremity of the rifle bar by means of the coacting conical surfaces 5 and 6 and provided with a check valve con trolled passage therethrough. The longitudinal channel 26 in the rifle bar 25 may conveniently extend, however, clear through the rifle bar fromone end to the other so that its upper end opens into the compression cylinder 16. The upper and lower ends of the cylinder 19 are arranged to be connected by a suitable passage 22,.such as 'is conveniently in the form'of an annular chamber, so that it,-will likewise constitute a receiverspace, the upper-end of'thc'pas sage being controlled-by it guarantees,

while the lower end enters the cylinder 19 at the bottom thereof through the? freely open port or passage 24a The cylinder at its lower end is provided with a -valve 21 similar to the hand operated regulator valve 18 in the cylinder 16. The drill, as a whole, operates as follows: Air being com-- pressed by the compression piston 32, passes through the passages 20 into the cylinder 19 above the percussion piston 28. This drives the piston downward and as the piston in its downward movement uncovers the upper opening of the passage 22, the compressed air will pass the check valve 23 down through the passage 22 to the lower end of the cylinder 19 beneath the percumion piston 28; Then as the compression piston 32 rises the air which has passed the check valve 13 will be trapped'thereby and will operate tov lift the percussion piston in a return stroke, the upward movement of the compression piston relieving the upper side of the percussion piston at this time. In the downward movement of the percussion piston, motive fluid under pressure will be admitted through the longitudinal channel '26 in the rifle bar 25 and through the hollow cushioning piston 7 into the lower end of thecylindrical cavity 27 in the percussion piston 28, and upon the return movement of the piston the airwill be trapped therein as in the construction of Fi s. 1 to 6 inclusive, to thereby act as an efiec i ve cushion to prevent the piston from striking the upper wall or head'and to otherwise act upon the pis-- ton in its next succeeding downward movement as stated above. j

In either of the structures described it will of course be understood that the effective area of the percussion piston upon which'the motive fluid acts to move it in a return stroke is greater than that of the cushioning piston which opposes it. In the structure shown in Figs. 1 to 6 inclusive in which the motive fluid operated to actuate the percussion piston in its return movement is employed at full motive fluid pres sure, the relative areas are about three to "one, while in the structure shown in Figs.

7 and 8, in which the motive fluid is used expansiv ely when actuating the percussion piston in its return movement, the pro ortional difierence is much greater. T ese proportions may of course be very varied to suitdifi'erent conditions and requirements.

It 'will be noted that in both of the constructions herein described the piston 20 at the end of the rifle bar acts as an outboard bearing for the rifle bar, supporting the rifle barin the movement of the piston, and thereby preventing undue wear upon the rifle bar or-upon the nut engaged thereby, and also tending to steady the parts so as to insure their roperoperation. Theoonical connection ween the piston and the ISO - struction because it a. compression cylinder, and

rifle bar is also a desirable feature of conprovides for the ready disconnection of the parts when the drill is taken apart for repair or other purposes. In reassembling the parts it is only neces sary to mount the piston in the cylindrical cavity because ,in the first stroke of the-percussion piston the motive fluid trapped in the cylindrical cavity beneath the cushioning piston will immediately act to lift the cushioning piston into position wherein it will intimately engage the conical end 5 of the rifle bar and thereafter the frictional engagement between the complementary conical parts 5 and 6, coupled with the air pressure, will tend to keep the parts in their proper engaged positions.

It will of course be understood that the two constructions shown and described are merely illustrative of types of tools to which in r invention may be advantageously empl yed, and it will also be clear that my in: velntion is equally adapted for employment with other forms and types of power operated percussive tools. stood that many of the details of construction and arrangement of parts of the cushioning means may be varied without dept rting from the spirit and scope of my inv 'ntion in its broad aspect.

{IVhat I claim is:

1. In an elastic fluid operated percussive t l, the combination with a cylinder and a percussion piston freely mounted therein, of means for applying elastic motive fluid against a given area of the piston to move it in one direction, and means for entrapping motive fluid, and for compressing it against a relatively smaller area of the piston, during substantially the entire movement of the said piston in such direction.

2. In an elastic fluid operated percussive tool, the combination Witha cylinder and a percussion piston freely mounted therein, the said piston presenting a relatively greater area upon one side for actuation by elastic motive fluid, and a relatively smaller area in opposition thereto for resisting such actuation, of means for admitting elastic motive fluid in the cylinder to opt-rate against the relatively large area of the piston to move it inone direction, and means for entrapping motive fluid, andfor compressing it by the said piston, throughout the said relatively smaller area, during substantially its entire movement in such direction.

3. An elastic fluid operated percussive tool comprising a main cylinder, a percussion piston mounted to reciprocate freely therein, a cushioning piston having a smaller eflective area than the percussion piston, mounted in the said compression cylinder, means for admitting elastic motive fluid in the main cylinder against the percussion alternately It will also be inlder-v thereof to continuously I the compression of rection.

piston to move it in tool, the combination with a cylinder and a percussion piston freely mounted therein, of means for admitting elastic motive fluid into the cylinder, against one side of the said piston to actuate it in one direction, and cushioning means of smaller effective area, operating to compress entrapped motive fluid duril'ig substantially the entire the said piston in such direction.

5. In a power operated percussive tool, the combination with a cylinder ant; apercussion piston mounted to reciprocat: freely therein, and means for admitting elastic motive fluid under pressure to the cylinde" upon opposite sides of the pie. ton, to alternately actuate the same in opposite directions, of means for compressing a portion of the motive fluid employed in moving the piston in one direction, during substantially the entire movement of the said piston in the opposite direction.

6. In a power operated percussive tool, the combination with a cylinder and a percussion pistonmounted to reciprocate freely therein, and means for admitting elastic motive fluid under pressure to the cylinder alternately upon oppositesides of the piston, to alternately actuatethe same in opposite directions, of means for completely entrapping a portion of the motive fluid employed in moving the piston in one (llI'GGtlOD, and for continuously compressing it while so completely entrapped during substantially the entire movement of the said piston in the opposite direction.

7. In a power operated percussive tool, the combination with a cylinder and a percussion piston mounted-to reciprocate freely therein, and means for admitting elastic motive fluid under pressure to the cylinder alternately upon opposite sides when moving the said piston in one-direction, whereby when the piston is moved in the other direction, the said piston will operate throughout the remaining portion compress such residual motive fluid, which'will progressively oppose the entire movement of the piston in the latter said di- 8. In an elastic fluid operated percussive tool,- the combination with a cylinder and a percussion piston freely mounted therein, and having a compression cylinder 1n ax al movement of alinement therewith, of a cushioning piston in the last said cylinder, a longitudinally stationary rod for carrying the stud cushioning piston, means for'admittin elastic motive fluid under pressure into the rst said cylinder upon opposite sides of the percussion piston, and into the said compression chamber in front of the said cushioning piston,

and means for completely entrapping the motive fluid in the said compression chamber, whereby it will be compressed during substantially the entire movement of the percussion piston in one direction, and will expend its energy to assist in the actuation of the said percussion piston when the latter is moving in the opposite direction.

9. In mechanism of the class described, the combination with a main cylinder and a percussion piston freely mounted therein and having a coaxial cylindrical cavity, of a cushioning piston mounted in the said cylindrical cavity, a longitudinally fixed rod to which the-said cushionin piston is attached, means for admitting elastic motive fluid under pressure into the main cylinder alternately upon opposite sides of the percussionpiston, and into the said cylindrical cavity, and nonreturn means for preventing the escape of motive fluid from the said cylindrical cavity.

10. In a rock drill the combination with a main cylinder and a percussion piston freely mounted therein, and having a co-axial cylindrical cavity, of a longitudinally stationary rotator bar carried at one end by thesaid main cylinder and at the other end projecting into the said cylindrical cavity, a cushioning piston carried by the latter end of the said rotator bar, and means for admitting an elastic fluid into, and entrapping it within, the said cylindrical cavity.

11. In a rock drill, the combination with a main cylinder and a percussion piston freely mounted therein and having a co-axial cylindrical cavity, of a; longitudinally fixed rotator bar received within the said cavity, a piston thereon fitted to the said cavity, means for admitting motive fluid to the said main cylinder, and check valve controlled passages for admitting motive fluid to the said cylindrical cavity.

12. In a rock drill, the combination with a main cylinder, and a percussion piston freely mounted therein, and having a cylindrical cavity, of a longitudinally fixed rotator bar received within the said cavity, and a piston fitted to the said cavity and detachably connected to thegend of the said rotator bar.

13. In a device of the character described, a percussiori cylinder,a percussion piston, a rotator'barga cylinder in said piston and in which the rgtator bar works, a piston for the latter said cylinder, and a friction joint for connecting the rotator bar and the latter said piston.

14:. In a device of the character described,

a percussion cylinder, a percussion piston, a

rotator bar, a cylinder in said piston and in which the said rotator bar works, a piston for the latter said cylinder, and a conical friction joint for connecting the rotator bar and the latter said piston.

15'. In a device of the character described, a percussion cylinder, a percussion piston, a rotator bar, a cylinder in the said piston, and in which the rotator bar works, an element fitted to the rotator barin sliding relation therewith, and carried by the piston, a piston in the cylinder in the said percussion piston, and self-engaging detachable connecting means between the second said piston and the said rotator bar.

16. In a device of the character described, a percussion cylinder, a percussion piston, a rotator bar, a cylinder in the said piston, and in which the rotator bar works, an eleinent fitted to the rotator bar in sliding relation therewith, and carried by the piston, a piston in the cylinder in the said percussion piston, and a friction joint for detachably connecting the second said piston with the said rotator bar.

17 In a device of the character described, a percussion cylinder, a percussion piston, a rotator bar, a cylinder in the said piston, and in which the rotator bar works, an element fitted to the rotator bar in sliding relation therewith, and carried by the piston, a piston in the cylinder in the said percussion piston, and a conical friction 'oint for detachably connecting the secon said piston with the said rotator bar.

18. In a rock drill, the combination with a main cylinder, a percussion piston freely mounted therein and having a longitudinal cylindrical cavity. and means for admitting elastic fluid into the cylinder alternately upon opposite sides of the said piston, of a rotator bar which enters thesaid cylindrical cavity, a hollow piston upon the end of the said rotator bar and fitted to the said cylindrical cavity, and a check valve in the said hollow piston, the said rotator bar having a channel thercthrough which affords connection bctwecn'the rear end of the main cylinder and the said hollow piston.

In testimony that I claim the foregoing I a I WVitnesses:

G. B. PRINDLE, M. LOBEL.

- 0opies off-this patent may obtained for live cents each, by addressing the i Conimissionerof Yet'ents,

I Washington, D. G.

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