US2298845A - Impact hammer - Google Patents

Impact hammer Download PDF

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Publication number
US2298845A
US2298845A US404633A US40463341A US2298845A US 2298845 A US2298845 A US 2298845A US 404633 A US404633 A US 404633A US 40463341 A US40463341 A US 40463341A US 2298845 A US2298845 A US 2298845A
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Prior art keywords
hammer
housing
impact
spring
motor
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US404633A
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Joseph M Schmied
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SKILSAW Inc
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SKILSAW Inc
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D11/00—Portable percussive tools with electromotor or other motor drive
    • B25D11/06—Means for driving the impulse member
    • B25D11/066—Means for driving the impulse member using centrifugal or rotary impact elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D11/00—Portable percussive tools with electromotor or other motor drive
    • B25D11/06—Means for driving the impulse member
    • B25D11/10—Means for driving the impulse member comprising a cam mechanism
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/18—Mechanical movements
    • Y10T74/18056—Rotary to or from reciprocating or oscillating
    • Y10T74/18296—Cam and slide

Definitions

  • the present inventione relates fto improvementsin' ⁇ impact hammers.h and; ⁇ more ⁇ particularly; to power driven impact hammers havingr; readily controllable4 speed? and'; concussion :variables:V
  • Onerobj ectflof the --fpresentfinvention iis-fito provide asimplefand effective -meansf'of -lvarying the impact rblow from one that ⁇ 'is ⁇ ha-rcL and fslowl to one that isfastandlighta l
  • Another .objectisvto provide :an .impact hammer. havinga. simple. and leiective compression movement'that is.easily regulable from heavy talight work. .l s t
  • a still"furtherpbject is to provide -Van impact hammerwitli animproved coolingrsystem that will tend to maintain rthehammer in a relatively cool condition and prevent overheating.
  • a yet further objectis to provide an impact hammer that is easily andreadily assembled' and disassembled, that'v may be. ⁇ adjusted without sacrice of speedv tovarious kinds oiwork, ⁇ that is' ⁇ less.” wearingfon the' parts and operator, .and Will not.overheat. ⁇
  • ZET-ig. ⁇ 1. is arview, .partlyfinsection,. througha hammer embodying- ⁇ the present-invention; j
  • Fig. 2.v isa vview'takerron.the line. 2-2..of-. Fig.. 1;- partly; inv section, lookinglin 4'the directiomof the arrows;
  • Fig. 5 is av sectional ⁇ viewrthroughy ⁇ the' :collar oi Fig'. 4i
  • Fig..r 6 isafplan view-ofthe hammer-withithe. housingf partial-1yremoved; ⁇ showingr the opera- ⁇ tion of the compression mechanism diagram-,- matically; and:
  • ligf4 7 ⁇ is ,-a.-view diagrammatically.showing ,certainvo-fr vtheparts ⁇ of- 'Figi 6- in elevation.
  • the-body1 portion orhousing-oi theham-mer is made Vup of simple'easily assembledparts.
  • reciprocable. impar-:tl ham-mer member. is operated by aspring means-thatis lcompressed. slowly at low ⁇ spring'lpressure by a ⁇ motor driven actuatingmeans ⁇ that provides an ⁇ increase in speedV of compressionrtoward a maximum and then a lessening-ofrthespeedruntil the maximum compression'is attained', when ⁇ the springlisreleased to-'drivefY the' impact .memberv forward.
  • a regulating or adjusting means isusedto vary the compression offthefspring means prior to ⁇ its release for'action ⁇ on the hammer in-givingfan operative-blow.
  • the spring compressionmis varied, a heavier orl lighter loadeis ladded toethe motor which increases or f decreases -the speed' oi consecutive' blows accordingly;
  • Shock? absorbing means ⁇ is-"mounted ⁇ adjacent the tool holding' portion oi 'the hammer 'tolessen the vibration and f reactional 'shocks 'transmitted to the housing and hammer ⁇ as a whole, and'thus to the body 'of the operator.
  • Other sh'oclabsorbing means is mounted in the impact member operatingassembly to absorb shocks and vibrationsbetween pinion andgear members, the anti-'- frictionr bearings, motor windings, and other parts.
  • the impact hammer mechanism is mounted in a housing comprising a barrel portion I6, a gear housing II and a motor housing I2 all properly united into a ruggedly built and easily assembled whole through the use of bolts or other means not shown.
  • the barrel portion I includes a cylindrical bore I4 having a restricted bearing portion I1 in which an impact or hammer member I3 is reciprocally mounted.
  • an enlarged head member I5 having a tool driving face portion I6 and a shouldered portion I8 forming a bearing for one end of a hammer actuating spring means in the form of a compression spring member that is coiled around the stem 22 of the impact member.
  • the enlarged head member I5 slidably ts the bearing portion I1 of the bore I4 in the manner of a piston and reciprocates along the surface of the bearing, serving to position and guide the impact member at that place.
  • the stem 22 of the impact member Adjacent its rear, the stem 22 of the impact member extends through an annular collar 24 and is sildably mounted therein.
  • This collar is adjustably secured to the bore I4 of the barrel and forms a rear bearing for the impact member and properly positions and guides it at that point.
  • This adjustable collar at its forward end forms astop or bearing 25 for the other end of the spring member 20.
  • the collar 24 is slightly spaced from the stem 22 of the impact member to form a. stand-off thrust bearing and to afford a relatively loose fit between the stem and bearing at this point. This prevents any seizing or binding caused by the expansion of the parts from the heat created under the normal frictional engagement of the parts.
  • the collar 24 is adjustable axially of the stem 22 in the bore I4 to vary the compression of the spring 20 and thus to Vary the force of the blow to be given by the hammer member I3.
  • a helical thread 26 is formed terminating in a iiat top portion having screw threads 23 cut therein for purposes to be described hereinafter.
  • the bore I4 is screw threaded to form a nut portion to engage screw threads 28 on the helix of the compression collar 24.
  • a turning Vof the adjusting collar member in the nut portion 30 causes the collar to travel along the screw threaded portion of the bore to compress or release pressure on the spring member 20 and thereby adjust the force of the blow to be given by the impact member.
  • an adjusting worm screw 21 may be used. As shown, screw or bolt 21 extends into housing I I and has flights 3! arranged therearound to intermesh with helix 26 through a groove 32 in the barrel I0. A knurled cap on one end of the screw 21 and exterior to the housing may be used to obtain the desired tension on the spring.
  • a cylindrical bore 34 in the housing II accommodates the screw 21.
  • This screw may be hollow or formed with a cylindrical housingto receive a small compression spring 35 resting against its inner end and extending outwardly beyond the F same into contact with the inner end of bore 34. This spring tends to urge the bolt 21 out of the bore 34.
  • the screw is annularly grooved as at 36 (Fig. 3) and a pin 31 ex- 75 tends through an opening in the housing II and rides in the groove to hold the bolt in place.
  • a wider locking notch portion 38 is formed to cause the bolt to lock against turning by contact with pin 36 through pressure from spring 35.
  • Other widened lockingportions 38 may be inserted around the periphery of the screw 21, if desired.
  • the bolt For further adjustment after the pin has locked in the portion 38, the bolt must be pressed inwardly against the pressure of spring 35, and it may then be turned easily as the pin 31 now rides in the main portion of annular groove 36.
  • the bolt 21 is held in a predetermined adjusted position from which it cannot be dislodged by the vibration of the impact hammer. Only by manually adjusting the bolt can the compression of spring 20 be changed. If in adjusting the spring pressure, the operator does not lock the bolt in the nearest locking groove, vibration of the hammer member may loosen the bolt 21 only to a point where it will lock itself in the adjacent notch 38.
  • the return means for the hammer after an operative action by the spring means is simple and works smoothly and with less shock to the motor and gear members than that customarily in use.
  • the stem 22 is reduced in size and bent downwardly to form a hook-like projecting member 40.
  • the upper portion of this projecting member is flattened at 42 to pass under, and to be received within guide ilanges 43 of a roller bearing guide member 44 (Figs. l and 2) properly mounted in the housing I I.
  • the purpose of this guide means is to position the impact member I3 with respect to the bore I4 and the operating mechanism to be described and to prevent the hammer member from turning or rotating in the barrel.
  • a motor driven shaft 48 extends upwardly from the motor 46 into the gear housing II and carries a pinion 50 adjacent its upper end to mesh with teeth 52 on a gear assembly 54.
  • the gear assembly is formed to absorb shocks resulting from the vibration of the hammer, thereby preventing injury to the more delicate parts of the mechanism. It consists of several parts including an outer ring-like member provided with gear teeth 52 and an inner hub member 56 mounted onaspindle 51in a ball bearing mounting. Between the ring-like member and the hub, and spacing them from one another, is an annular shock absorbing ring 58 of rubber, or other similar resilient material, inserted between the two with a press fit. The shock absorbing ring may be enclosed on either side by the two metal annular members 59 and 60. This shock absorbing means also acts to overcome inertia in the actuating mechanism and provides an easier starting action to the motor in overcoming the force of spring 20 at each operating contact of the mechanism with the hammer member I3.
  • the barrel I0 may extend rearwardly over pinion 50 and a portion of the gear assembly 54 that may be formed as shown for this purpose.
  • a spindle 6I that carries a roller hammer actuating member 62 mounted thereon.
  • This member 62 upon rotation of the gear assembly, acts on the downwardly hooked portion 64 of the projecting member 46 to urge the hammer I3 rearaanmaninwarar again-.sti megas-noaa @funespringtmeml Frein tne-difagrammfatio views-sonnige. oand-.t 1?
  • the gear housing Il is formed with a handle portion 10 and a trigger switch arrangement 12 by which a proper electrical connection to the mo- At-v its l forward? end ⁇ the-barrel Ii'lis i provided with a toollholdiig1v device and-la fur-ther-lsliockf absorbing strueture: A't its mouth thefbarrel lii's sliglfitlyconstrictedl ⁇ In' this constricted' portion a grooved tool-holding member "is in serted", -and is separatedfrom the barrelf member by a rubber' annulus "T6, or shock absorbing means, somewhat similar in*- ⁇ structureL to the shockabsorbing memberlf Again; a.-p1ess ⁇ -i"1't ⁇ may be used for assembling these members.A
  • All tool-I havingf ak istem portion 18'?- may' be in-A serted in the toolhholdingmember' and? friction-- ally heldth'erein; A'ileath'er gasketlor cushion 8l! 'may li'e against' the inner sidei offftli'e con stricted portion-"of tlien'ioutli to receiiA/eI the eX cess blow" froml the' headV l'of the hammer if"A no tool sh'ank' is inthe tolilioldingf member; Pressure of,l the; tool on the workwill slidablyreturn-the ⁇ tool and ⁇ its stem?
  • This "interchange of air tends'to mair'rtain* ⁇ thefparts of the ⁇ -hammer at ,itsforf Ward-'en'din a relativelyacool condition 'andpre- Vents over-heating.r
  • An impact hammer including a reciprocable hammer member, a barrel housing enclosing said hammer member and having a mouth portion, a tool holding member in said mouth portion, said tool holding member being separated from said mouth portion by a shock absorbing member.
  • An impact hammer including a housing, a piston-like hammer member reciprocably mounted within said housing, an air inlet Valve in said housing operable to admit air on movement of said member in one direction and an air outlet valve in said housing to permit egress of air from the housing on movement of said member in the other direction.
  • an impact hammer having a housing and a reciprocable hammer member slidably mounted in said housing, means for varying the force of the blow to be given by said hammer member, said means including a compression spring operatively mounted at one end to said hammer member, a screw threaded portion in said housing adjacent the other end of said spring member, a threaded adjusting member for said spring mounted in said housing with its threads in operative engagement with the threaded portion of said housing and forming a stop member for the last mentioned end of said spring member, a helix on said adjusting member, and manual adjusting means meshing with said helix to turn said adjusting member along the screw threaded portion in said housing to compress or release tension on said spring member.
  • An impact hammer including a barrel housing having a mouth portion, a piston-like hammer member reciprocably mounted within said housing, a tool holding member in said mouth portion, and Ventilating grooves tortuously formed in said tool holding member operable to permit tortuous ingress of air to said housing 0n movement of said hammer member in one direction and tortuous egress of air on movement of said hammer member in the other direction.
  • An impact hammer including a barrel housing having a mouth portion, a piston-like hammer member reciprocably mounted within said housing, a tool holding member in said mouth portion, and Ventilating grooves formed in said tool holding member operable to permit ingress of air to said housing on movement of said hammer member in one direction and egress of air on movement of said hammer member in the other direction, said grooves being formed spirally around the interior of said tool holding member adjacent any tool held therein.
  • An impact hammer member including a housing, a hammer member reciprocably mounted in said housing, spring means for reciprocating said hammer for an operative blow in one direction, and return means for reciprocating said hammer in the other direction against the action of said spring means, said return means including a motor operated shaft having a pinion thereon, a rotatable gear wheel meshing with said pinion, a crank member eccentrically mounted on said gear wheel, and a projecting member on said hammer member for intermittent operative engagement by said crank member as it rotates in the orbit of said gear wheel, the radius of engagement of said crank member with said hooklike member from the center of said gear Wheel increasing from the point of contact to the point of departure from said projecting member.
  • An impact hammer member including a housing, a hammer member reciprocably mounted in said housing, spring means for reciprocating said hammer for an operative blow in one direction, and return means for reciprocating said hammer in the other direction against the action of said spring means, said return means including a motor operated shaft having a pinion thereon, a rotatable gear Wheel meshing with said pinion, a crank member eccentrically mounted on said gear wheel, and a projecting member on said hammer member for intermittent operative engagement by said crank member as it rotates in the orbit of said gear wheel, said gear wheel being so mounted that a diameter therethrough Will pass substantially through the point of engagement and disengagement of said crank member with said projecting member.
  • An impact hammer including a housing, a hammer member reciprocably mounted in said housing ,means for reciprocating said hammer member for an operative blow in one direction, member in another direction to position the same return means for reciprocating said hammer for an operative blow, and guide means in said housing cooperating with said hammer member to maintain said hammer member in operative position to be actuated by said return means, said guide means including a flattened portion on said hammer member and a roller guide member mounted in said housing contacting said iiattened portion to prevent rotation of said hammer in the housing.

Description

Oct.` 13, 1942. J, M scHMlED 2,298,845
y IMPACT HAMMER Filed July 30, 1941 2 Sheets-Sheet 2 l INVENT OR.
Patented Oct. 13; 1942 2,298,845'Trl D? PAI ENT O'F FIGEZ IIVIPACT HAlWlWER-f Application J uly, 30,- 1941,..S,erial.Not .404,633l
(C11 M5L-33) 10` Claims.v
The present inventionerelates fto improvementsin'` impact hammers.h and;` more` particularly; to power driven impact hammers havingr; readily controllable4 speed? and'; concussion :variables:V
Heretofore f attempts f have been made to fvary the force. of afblowtgiven Vbyearrimpact hammer and.n toA vary# the :speed with which successive creasing the air;- supply: However; ',withithe-morepovrverfu'l` ablowy` the: speed of successive fblows is increased `whilefin light impact-worm the :speed of successive blows is greatly-,f decreased; This mean's a'- greatdossf or timerinrfragilelongfwork performance, while. thef increased l number@` of blowsin heavy` work'.` causesvunduef wear.v to -the tool:` and laborfto- .theroperatorfin :handling-dt:`
Most impact hammers lfailfbecause shocks land vibrations from the repeated impacts areftra-ns-Y mitted tof the motor.` windings*V gears-A and fantifriction bearings; This-likewise tires='thefopera tor; and hasbecomeronefof the.u problems inthis type-of implement. A furtherfproblem in thesetools has-beenf-gettinggridof the Vfrictionasl `heat generated' byf the? rapidlymoving; partsthat' isv otherwiseY destructive to?" the mechanism:
Onerobj ectflof the --fpresentfinvention iis-fito provide asimplefand effective -meansf'of -lvarying the impact rblow from one that` 'is `ha-rcL and fslowl to one that isfastandlighta l Another .objectisvto provide :an .impact hammer. havinga. simple. and leiective compression movement'that is.easily regulable from heavy talight work. .l s t A further Objectis to provide an impact .hamm'er having'improved"shock absorbing means'v for the. protection of "the'parts and-of' the operator.
A still"furtherpbject is to provide -Van impact hammerwitli animproved coolingrsystem that will tend to maintain rthehammer in a relatively cool condition and prevent overheating.l
A yet further objectis to provide an impact hammer that is easily andreadily assembled' and disassembled, that'v may be.` adjusted without sacrice of speedv tovarious kinds oiwork,` that is'` less." wearingfon the' parts and operator, .and Will not.overheat.`
In the accompanying drawingsf one@ embodi- CII ment of the inventionisvshow-rr and isgdescribed 55` in the. following. specification.. for purposes.J of exemplii'lcation lonly... Various.. other modifications and adaptations will at oncefbecome rap.-u parent to one skilled, in .the art.-
Inv thedrawings.
ZET-ig.` 1. is arview, .partlyfinsection,. througha hammer embodying- `the present-invention; j
Fig. 2.v isa vview'takerron.the line. 2-2..of-. Fig.. 1;- partly; inv section, lookinglin 4'the directiomof the arrows;
Eig. 3 :is -a .view taken lon Lthe.4 line, 3.7-3. ofiFig l, partly in section, looking inthe..directiomof the 'arrows Figffl-is a view-partly-in ysection of a regulating collarand-bearing usable with the invention;
Fig. 5 is av sectional `viewrthroughy `the' :collar oi Fig'. 4i
Fig..r 6 isafplan view-ofthe hammer-withithe. housingf partial-1yremoved;` showingr the opera-` tion of the compression mechanism diagram-,- matically; and:
ligf4 7 `is ,-a.-view diagrammatically.showing ,certainvo-fr vtheparts` of- 'Figi 6- in elevation.
Infaccomplishingthe objects of this invention the-body1 portion orhousing-oi theham-mer is made Vup of simple'easily assembledparts.. Briefly, reciprocable. impar-:tl ham-mer member. is operated by aspring means-thatis lcompressed. slowly at low `spring'lpressure by a `motor driven actuatingmeans `that provides an` increase in speedV of compressionrtoward a maximum and then a lessening-ofrthespeedruntil the maximum compression'is attained', when` the springlisreleased to-'drivefY the' impact .memberv forward. A regulating or adjusting means isusedto vary the compression offthefspring means prior to` its release for'action `on the hammer in-givingfan operative-blow. As o. the spring compressionmis. varied, a heavier orl lighter loadeis ladded toethe motor which increases or f decreases -the speed' oi consecutive' blows accordingly;
Shock? absorbing means `is-"mounted` adjacent the tool holding' portion oi 'the hammer 'tolessen the vibration and f reactional 'shocks 'transmitted to the housing and hammer `as a whole, and'thus to the body 'of the operator. Other sh'oclabsorbing means is mounted in the impact member operatingassembly to absorb shocks and vibrationsbetween pinion andgear members, the anti-'- frictionr bearings, motor windings, and other parts..
The rapidly moving impact member is used as appart `of.thecooling=,system.to suck in outside airto;flush ,thegears bearings and-.,entirehousing and to force out heated air in combination with a novel valve and groove arrangement.
As shown, the impact hammer mechanism is mounted in a housing comprising a barrel portion I6, a gear housing II and a motor housing I2 all properly united into a ruggedly built and easily assembled whole through the use of bolts or other means not shown.
The barrel portion I includes a cylindrical bore I4 having a restricted bearing portion I1 in which an impact or hammer member I3 is reciprocally mounted. At the forward end of the impact member is an enlarged head member I5 having a tool driving face portion I6 and a shouldered portion I8 forming a bearing for one end of a hammer actuating spring means in the form of a compression spring member that is coiled around the stem 22 of the impact member.
The enlarged head member I5 slidably ts the bearing portion I1 of the bore I4 in the manner of a piston and reciprocates along the surface of the bearing, serving to position and guide the impact member at that place.
Adjacent its rear, the stem 22 of the impact member extends through an annular collar 24 and is sildably mounted therein. This collar is adjustably secured to the bore I4 of the barrel and forms a rear bearing for the impact member and properly positions and guides it at that point. This adjustable collar at its forward end forms astop or bearing 25 for the other end of the spring member 20.
The collar 24 is slightly spaced from the stem 22 of the impact member to form a. stand-off thrust bearing and to afford a relatively loose fit between the stem and bearing at this point. This prevents any seizing or binding caused by the expansion of the parts from the heat created under the normal frictional engagement of the parts.
The collar 24 is adjustable axially of the stem 22 in the bore I4 to vary the compression of the spring 20 and thus to Vary the force of the blow to be given by the hammer member I3. On the collar 24 a helical thread 26 is formed terminating in a iiat top portion having screw threads 23 cut therein for purposes to be described hereinafter. At its rear portion, the bore I4 is screw threaded to form a nut portion to engage screw threads 28 on the helix of the compression collar 24. A turning Vof the adjusting collar member in the nut portion 30 causes the collar to travel along the screw threaded portion of the bore to compress or release pressure on the spring member 20 and thereby adjust the force of the blow to be given by the impact member.
To obtain this turning movement for regulating and adjusting the spring pressure, an adjusting worm screw 21 may be used. As shown, screw or bolt 21 extends into housing I I and has flights 3! arranged therearound to intermesh with helix 26 through a groove 32 in the barrel I0. A knurled cap on one end of the screw 21 and exterior to the housing may be used to obtain the desired tension on the spring.
A cylindrical bore 34 in the housing II accommodates the screw 21. This screw may be hollow or formed with a cylindrical housingto receive a small compression spring 35 resting against its inner end and extending outwardly beyond the F same into contact with the inner end of bore 34. This spring tends to urge the bolt 21 out of the bore 34.
To counteract this pressure, the screw is annularly grooved as at 36 (Fig. 3) and a pin 31 ex- 75 tends through an opening in the housing II and rides in the groove to hold the bolt in place. In the periphery of the groove 36 a wider locking notch portion 38 is formed to cause the bolt to lock against turning by contact with pin 36 through pressure from spring 35. Other widened lockingportions 38 may be inserted around the periphery of the screw 21, if desired. For further adjustment after the pin has locked in the portion 38, the bolt must be pressed inwardly against the pressure of spring 35, and it may then be turned easily as the pin 31 now rides in the main portion of annular groove 36. By this arrangement the bolt 21 is held in a predetermined adjusted position from which it cannot be dislodged by the vibration of the impact hammer. Only by manually adjusting the bolt can the compression of spring 20 be changed. If in adjusting the spring pressure, the operator does not lock the bolt in the nearest locking groove, vibration of the hammer member may loosen the bolt 21 only to a point where it will lock itself in the adjacent notch 38.
The return means for the hammer after an operative action by the spring means is simple and works smoothly and with less shock to the motor and gear members than that customarily in use. At its inner end the stem 22 is reduced in size and bent downwardly to form a hook-like projecting member 40. The upper portion of this projecting member is flattened at 42 to pass under, and to be received within guide ilanges 43 of a roller bearing guide member 44 (Figs. l and 2) properly mounted in the housing I I. The purpose of this guide means is to position the impact member I3 with respect to the bore I4 and the operating mechanism to be described and to prevent the hammer member from turning or rotating in the barrel.
Within the motor housing I 2 is a standard universal motor 46. A motor driven shaft 48 extends upwardly from the motor 46 into the gear housing II and carries a pinion 50 adjacent its upper end to mesh with teeth 52 on a gear assembly 54.
The gear assembly is formed to absorb shocks resulting from the vibration of the hammer, thereby preventing injury to the more delicate parts of the mechanism. It consists of several parts including an outer ring-like member provided with gear teeth 52 and an inner hub member 56 mounted onaspindle 51in a ball bearing mounting. Between the ring-like member and the hub, and spacing them from one another, is an annular shock absorbing ring 58 of rubber, or other similar resilient material, inserted between the two with a press fit. The shock absorbing ring may be enclosed on either side by the two metal annular members 59 and 60. This shock absorbing means also acts to overcome inertia in the actuating mechanism and provides an easier starting action to the motor in overcoming the force of spring 20 at each operating contact of the mechanism with the hammer member I3.
For compactness of assembly the barrel I0 may extend rearwardly over pinion 50 and a portion of the gear assembly 54 that may be formed as shown for this purpose.
Mounted eccentrically on the hub 56 is a spindle 6I that carries a roller hammer actuating member 62 mounted thereon. This member 62, upon rotation of the gear assembly, acts on the downwardly hooked portion 64 of the projecting member 46 to urge the hammer I3 rearaanmaninwarar again-.sti megas-noaa @funespringtmeml Frein tne-difagrammfatio views-sonnige. oand-.t 1?
ber-1 6121'intermittentlyf'strikstheiiinner fak-ieV 66? off the hookllikef member: adjacentione edge byl'tle -arrew-'B"-. Thisl-means thatati thei'point ofE contactl the rollerfmember strikes the face'- 66 at ant exceedingly?aoutefangl andbegins Theispeed of compression .is-` greatly ir'rcreasedvv through' any arc-f ofsubstantially 909i andf' then, duringftliefperiod off greatestcompression; the speed gradually-1 decreases 2 toV I the1 point of i departure or disengagement with facef 65.
thefpoint ofiw departure andi at the maxir'num` sion yof spring';
Were the gearassembly" centered wth the e.Xis'`of` the hammer member; the face-portion 65 would-have to `beL shortened orth`ere"would` be a longer contact of the roller 62`-with""theY projecting memberat the point approximating maximum spring compression with consequent greater strain on the parts. The roller E2 would disengage from the face 66 after the point of maximum spring compression had been reached. The guide member 44 in cooperation with the attened portion 42 provides means for maintaining the projecting member and its hooklike member 64 in proper or operative position to be actuated by the crank roller B2.
It will be apparent that as the screw 21 is adjusted, compression of the spring 20 will be increased or decreased. This will have a direct relation on the motor assembly 46. By increasing the spring tension, the motor will be slowed under the heavier work given to it and the result will be a slower, harder blow by the hammer I0. By decreasing the spring tension the load on the motor will be lessened, permitting a rapid rotation and a resulting light, fast blow.
At the rear end of the hammer assembly, the gear housing Il is formed with a handle portion 10 and a trigger switch arrangement 12 by which a proper electrical connection to the mo- At-v its l forward? end` the-barrel Ii'lis i provided with a toollholdiig1v device and-la fur-ther-lsliockf absorbing strueture: A't its mouth thefbarrel lii's sliglfitlyconstrictedl` In' this constricted' portion a grooved tool-holding member "is in serted", -and is separatedfrom the barrelf member by a rubber' annulus "T6, or shock absorbing means, somewhat similar in*-` structureL to the shockabsorbing memberlf Again; a.-p1ess`-i"1't` may be used for assembling these members.A
All tool-I havingf ak istem portion 18'?- may' be in-A serted in the toolhholdingmember' and? friction-- ally heldth'erein; A'ileath'er gasketlor cushion 8l! 'may li'e against' the inner sidei offftli'e con stricted portion-"of tlien'ioutli to receiiA/eI the eX cess blow" froml the' headV l'of the hammer if"A no tool sh'ank' is inthe tolilioldingf member; Pressure of,l the; tool on the workwill slidablyreturn-the `tool and`` its stem? 18?' into auf 0perativen position to receive a blow@ from theu ham# mer Il);l Directfvibrationfromthe tool-will be absorbed byv resilientl means 16 tending tolpre- Vent shocks from being 'transmitted to the barrel and lto the-Ioperators 'lands:'
The tolU4 holding member mayv beinternally spirally-` grooved as-*at i 8-2 i to forml a tortu'ous`- air passage for permittingfiigress ofcool-Iou'ter air v upon a=-b"a'ckwardl air"sucling-fmovementiof the hammer headl I 5 andv'egress to h'eatedi airrup'on` a forwardair pushing movement'of``this pistonlike member. This "interchange of air tends'to mair'rtain*` thefparts of the`-hammer at ,itsforf Ward-'en'din a relativelyacool condition 'andpre- Vents over-heating.r
Fr-fcoolig the-gears; andmotor housing; theA mechanisms therein, and: the vcyli"nd1`-ical bore; an ai inleti vailveshown as' aA` ball"`se'aled"` oiler4 84'mayf beltinsertediin' the housing`- Hi Upon anoperative forwardstrokefof the hammer I3, outside` air WililVbedrawn into the housing" Il andpass arounditheivariousparts and intothe' bore pastfthecollar' 24: Anotherball 'sealed oiler 86* acting' asb arr air outlet Valve may be mountedin reverselin' thehousing H toY permit heated airi to be-expelled from the'housin'g by the' reverse^stroke of' the hammer IB caused by thejroller' 64? Oiler 84 may also" be used for lubricatingr the moving parts.`
Both the head !5""and"the"`stem"20are'pror vided lwitli lubricating grooves 88to -carry"`lubricating material in the bore I4 to their respective bearings.
The invention herein described may be incorporated into `various other embodiments and modifications that will be apparent to those skilled in the art. All such embodiments coming within the spirit of the invention are intended to be included within the scope of the appended claims.
I claim:
1. An impact hammer, including a reciprocable hammer member, a barrel housing enclosing said hammer member and having a mouth portion, a tool holding member in said mouth portion, said tool holding member being separated from said mouth portion by a shock absorbing member.
2. An impact hammer, including a housing, a piston-like hammer member reciprocably mounted Within said housing, an air inlet Valve in said housing operable to admit air on movement of said member in one direction and an air outlet valve in said housing to permit egress of air from the housing on movement of said member in the other direction.
3. An impact hammer as defined in claim 2, wherein the air inlet and outlet valves are ball sealed oiler members and the outlet valve is mounted to be operative from the interior only of said housing.
4. In an impact hammer having a housing and a reciprocable hammer member slidably mounted in said housing, means for varying the force of the blow to be given by said hammer member, said means including a compression spring operatively mounted at one end to said hammer member, a screw threaded portion in said housing adjacent the other end of said spring member, a threaded adjusting member for said spring mounted in said housing with its threads in operative engagement with the threaded portion of said housing and forming a stop member for the last mentioned end of said spring member, a helix on said adjusting member, and manual adjusting means meshing with said helix to turn said adjusting member along the screw threaded portion in said housing to compress or release tension on said spring member.
5. An impact hammer as defined in claim 4, wherein said adjusting member is formed as a collar around said hammer member and has a sliding engagement therewith.
6. An impact hammer, including a barrel housing having a mouth portion, a piston-like hammer member reciprocably mounted within said housing, a tool holding member in said mouth portion, and Ventilating grooves tortuously formed in said tool holding member operable to permit tortuous ingress of air to said housing 0n movement of said hammer member in one direction and tortuous egress of air on movement of said hammer member in the other direction.
7. An impact hammer, including a barrel housing having a mouth portion, a piston-like hammer member reciprocably mounted within said housing, a tool holding member in said mouth portion, and Ventilating grooves formed in said tool holding member operable to permit ingress of air to said housing on movement of said hammer member in one direction and egress of air on movement of said hammer member in the other direction, said grooves being formed spirally around the interior of said tool holding member adjacent any tool held therein.
8. An impact hammer member, including a housing, a hammer member reciprocably mounted in said housing, spring means for reciprocating said hammer for an operative blow in one direction, and return means for reciprocating said hammer in the other direction against the action of said spring means, said return means including a motor operated shaft having a pinion thereon, a rotatable gear wheel meshing with said pinion, a crank member eccentrically mounted on said gear wheel, and a projecting member on said hammer member for intermittent operative engagement by said crank member as it rotates in the orbit of said gear wheel, the radius of engagement of said crank member with said hooklike member from the center of said gear Wheel increasing from the point of contact to the point of departure from said projecting member.
9. An impact hammer member, including a housing, a hammer member reciprocably mounted in said housing, spring means for reciprocating said hammer for an operative blow in one direction, and return means for reciprocating said hammer in the other direction against the action of said spring means, said return means including a motor operated shaft having a pinion thereon, a rotatable gear Wheel meshing with said pinion, a crank member eccentrically mounted on said gear wheel, and a projecting member on said hammer member for intermittent operative engagement by said crank member as it rotates in the orbit of said gear wheel, said gear wheel being so mounted that a diameter therethrough Will pass substantially through the point of engagement and disengagement of said crank member with said projecting member.
10. An impact hammer, including a housing, a hammer member reciprocably mounted in said housing ,means for reciprocating said hammer member for an operative blow in one direction, member in another direction to position the same return means for reciprocating said hammer for an operative blow, and guide means in said housing cooperating with said hammer member to maintain said hammer member in operative position to be actuated by said return means, said guide means including a flattened portion on said hammer member and a roller guide member mounted in said housing contacting said iiattened portion to prevent rotation of said hammer in the housing.
JOSEPH M. SCHMIED.
CERTIFICATE oF CORRECTION. Patent No. 2,298,8LT5. october 15, 19h@ JOSEPH M. SCHMIED.
It .is hereb)T Certified that error, appears in the 'printed specification of the above numbered patent requiring correction as follows; Page 2, first Column, line 26, for '"Sldably" read --slidably--g page )4., second oo'imnn,4 Y
` line [4.0, e' La L1:n2LO,strikev out member in another direction to position the same and insert the same after "hammer" in linelil, same claim; and that the said Letters Patent should be read with this veorreetion therein that the same may c'onfonn to the record of the Case in the Patent Office.
Signed and sealed this 214th day of November, A. D. 19lL2.
. Henry Van Azfsdale,v (Seal) 4 Acting Commissioner of Patents.
US404633A 1941-07-30 1941-07-30 Impact hammer Expired - Lifetime US2298845A (en)

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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2501542A (en) * 1947-10-15 1950-03-21 Harold S Sheldon Hammer tool
US2623544A (en) * 1946-09-30 1952-12-30 Rockwell Mfg Co Automatic sampler
US3376940A (en) * 1966-05-10 1968-04-09 Richard K. Willis Powered hand hammer
US3785444A (en) * 1972-10-10 1974-01-15 P Gray Jackhammer
US4030556A (en) * 1975-09-22 1977-06-21 Phillips Raymond J Miniature impact tool
US4645015A (en) * 1985-09-12 1987-02-24 Mitchell William C Powered impact instrument
US20080066938A1 (en) * 2006-09-18 2008-03-20 The Stanley Works Ground stabilized transportable drop hammer

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2623544A (en) * 1946-09-30 1952-12-30 Rockwell Mfg Co Automatic sampler
US2501542A (en) * 1947-10-15 1950-03-21 Harold S Sheldon Hammer tool
US3376940A (en) * 1966-05-10 1968-04-09 Richard K. Willis Powered hand hammer
US3785444A (en) * 1972-10-10 1974-01-15 P Gray Jackhammer
US4030556A (en) * 1975-09-22 1977-06-21 Phillips Raymond J Miniature impact tool
US4645015A (en) * 1985-09-12 1987-02-24 Mitchell William C Powered impact instrument
US20080066938A1 (en) * 2006-09-18 2008-03-20 The Stanley Works Ground stabilized transportable drop hammer
US7775296B2 (en) * 2006-09-18 2010-08-17 The Stanley Works Ground stabilized transportable drop hammer

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