CN102069477B - Power hammer - Google Patents

Abstract

The invention relates to a power hammer, which comprises a striking device. The striking device comprises a striking element and a clamping mechanism, wherein the striking element is used for repeatedly striking components; the clamping mechanism comprises a clamping element, a casing pipe, a first skewing device and a second skewing device; the casing pipe is provided with slots; the clamping element slides in the slots; the clamping element is closed relative to the first positions of the slots; the clamping element is opened relative to the second positions of the slots; the first skewing device is used for skewing the casing towards the direction of the striking element striking the components; the clamping mechanism also comprises a cutting ferrule; and the second skewing device is used for acting on the cutting ferrule towards the direction of the striking element striking the component to skew the clamping element. The power hammer has a compact structure, is convenient to operate and can be used for well clamping nails or other components so as to avoid that the nails or other components are struck to incline.

Description

A kind of power hammer

The application is for application number is 200910234451.0, the applying date is on November 19th, 2009, title is divided an application for " a kind of power hammer " China's application.

Technical field

The present invention relates to a kind of power hammer, relate to a kind of power hammer that has clamp mechanism especially.

Background technology

In decoration, finishing field, the power hammer is a kind of instrument comparatively commonly used, number is the 200820161342.1 power hammers that disclose like one Chinese patent application, and it comprises the rifle mouth portion that fuselage part and links to each other with fuselage.The rifle mouth portion generally is made up of the cylinder-shaped sleeve of a hollow, is drilled with the hole that can place magnet on this sleeve pipe, thereby magnet is engaged on and adsorbs the nail that is placed in the beating unit in this hole, thereby nail is clamped.The defective of its existence is: magnet is in sleeve edge, can't make nail be in cover tube hub and element not parallel with the sleeve pipe center line (being to be askew after nail adsorbs), and can not clamp other nonmagnetic material, like dowel etc.

Summary of the invention

The objective of the invention is to: the shortcoming to above-mentioned prior art exists, a kind of power hammer is proposed, nail or other element can be by firm being clamped in the beating unit, thus person easy to use uses.

To achieve these goals, provide a kind of easy and simple to handle, visual good; The power hammer of compact conformation, it comprises that one impacts device, this beating unit comprises hit piece and clamp mechanism; This hit piece is used for impacting repeatedly element, and this clamp mechanism comprises clamping element, first bias unit and second bias unit, and this sleeve pipe is provided with groove; Clamping element slides in groove, the primary importance of clamping element opposed slot, and clamping element is closed; The second place of clamping element opposed slot, clamping element is opened, and this first bias unit is used for impacting the component orientation off-set sleeve towards hit piece; This clamp mechanism also comprises a cutting ferrule, thereby the directive effect that second bias unit is used for impacting element towards hit piece is in cutting ferrule biasing clamping element.The benefit that is provided with first bias unit and second bias unit is that nail or other element can be by firm being clamped in the clamp mechanism.During work; Nail or other element are clamped in the clamp mechanism; When being driven into the certain depth rear sleeve, nail contacts with workpiece; At this moment in order to continue nail is squeezed in the workpiece, then the user need overcome the bias force of first bias unit, makes sleeve pipe impact the opposite direction motion of element to hit piece; When sleeve movement is the main body of clamp mechanism when contacting with workpiece to flushing with the main body of clamp mechanism, the user then need overcome the bias force of first bias unit and second bias unit, makes sleeve pipe continue to impact to hit piece the opposite direction motion of element.

Further; This power hammer also comprises housing, motor, transmission mechanism and impacts assembly; This motor vertically is installed in the housing; Transmission mechanism through bevel gear with impact assembly and convert rotatablely moving of motor the percussion action of hit piece to, this impacts assembly comprises the impact block that is contacted by the impact portion branch with hit piece.On a kind of like this power hammer because hit piece can impact nail or other element with very big power, so the clamp mechanism that is provided with therein can well clamping nail or other element, in order to avoid nail or other element are deflected.

Further; This bias unit comprises first bias unit and second bias unit; This first bias unit is used for impacting towards hit piece the direction off-set sleeve of element; Also comprise a cutting ferrule in the clamp mechanism, thereby the directive effect that second bias unit is used for impacting element towards hit piece is in cutting ferrule biasing clamping element.

At least two faces of this sleeve pipe are provided with the groove group, and the groove on each face is mutually symmetrical, and this clamping element comprises drive part, and this drive part places in the groove, and this drive part can move along groove.Preferably, four faces of this sleeve pipe are provided with the groove group, and the groove on each face is mutually symmetrical, and the drive part of clamping element places in the groove, and this drive part can move along groove.Four faces of sleeve pipe are provided with the groove group, make the shank of the clamping nail that clamping element can be wider, and grip is better.

Further, groove is set to broken line type, helps the sliding stroke of reentrant bushing like this, makes the more compact structure of complete machine.

Further, drive part is removably mounted on the clamping element and/or with clamping element all-in-one-piece is set.

Further, clamping element comprises each or any combination of the claw, spring, magnet, screw or the chuck that are used for holding element.

Further, clamping element comprises groove, and in closing position, element is maintained in this groove, and at open position, element and this groove break away from.

Further, beating unit comprises a hit piece, when clamping element is positioned at open position, forms a release areas, and this hit piece can pass through this release areas.

Further, this clamp mechanism comprises a lining, and this lining can pass through this release areas.This lining is arranged on the periphery of hit piece, can effectively prevent like this nail or other element be stuck in machine especially clamping element open in the slit of generation.

Further, this clamp mechanism comprises the 3rd bias unit, and the 3rd bias unit impacts the direction offset liner of element towards hit piece.

Further, clamping element can be interlocked, and helps clamping element like this and opens with simultaneously closed simultaneously.

Further, sleeve pipe comprises a locking mechanism, and this locking mechanism comprises at least one convexity and spanner, and after a convexity and spanner locking, clamping element is positioned at open position, and after another convexity and spanner locked, lining exposed from sleeve pipe.

Further, this sleeve pipe is provided with sheath.Thereby a toggle engages with this sheath and makes toggle and sheath move.The user can push sheath or promote toggle and make clamping element open.

Further, sheath and/or sleeve pipe are made by transparent material, make things convenient for the user to see the particular location of hit piece.

Further, thus sheath and/or sleeve pipe are provided with the visuality that groove increases element.

This power hammer can be firm nail or other element are grasped, and small and exquisite, the user is easy to use, chucking power is reliable, can bail, visual good.

Description of drawings

Below with preferred embodiment and combine accompanying drawing that the present invention is further described.Wherein:

Fig. 1 is the schematic perspective view of medium power hammer of the present invention.

Fig. 2 is the cutaway view that power hammer shown in Figure 1 is done along the parting surface of two halves housing.

Fig. 3 is that power hammer shown in Figure 1 is along the cutaway view of doing perpendicular to the direction of two halves housing parting surface.

Fig. 4 is the part explosive view of Fig. 1 medium power hammer transmission mechanism.

Fig. 5 is the cutaway view that power hammer shown in Figure 2 is done along the A-A axis.

Fig. 6 is the partial enlarged drawing of the clamp mechanism of power hammer shown in Figure 1, and wherein, clamping element is positioned at closing position.

Fig. 7 is the partial enlarged drawing of the clamp mechanism of power hammer shown in Figure 1, and wherein, clamping element is positioned at the fully open position.

Fig. 8 is a clamp mechanism shown in Figure 6 cutaway view along the B-B axis.

Fig. 9 is a clamp mechanism shown in Figure 7 cutaway view along the C-C axis.

Figure 10 is the sketch map that nail is clamped in the clamp mechanism and the sleeve pipe of power hammer just contacts with workpiece, and at this moment, clamping element is positioned at open position soon.

Figure 11 be nail be tufted in the workpiece and the sleeve pipe of power hammer on convexity just back down the sketch map of spanner.

Figure 12 is the sketch map that nail is tufted in the workpiece and the main body of the clamp mechanism of power hammer just contacts with workpiece, and at this moment, clamping element is positioned at the fully open position.

Figure 13 is the sketch map that nail is tufted in the workpiece and the lining of the clamp mechanism of power hammer just contacts with workpiece.

Figure 14 is that nail is hammered into the sketch map in the workpiece fully.

The specific embodiment

As depicted in figs. 1 and 2, the power hammer 1 of present embodiment comprises and holds motor M at interior housing 2 and beating unit 6, and housing 2 is by left and right sides two halves housing 2 ', 2 ' ' involute.The main part of housing 2 forms vertical basically holding area 4, and the upper end comprises head assembly 3, and this head assembly comprises transmission mechanism and protrudes the beating unit 6 that forms forward.

In this embodiment, power hammer 1 comprises a power brick (not shown), is used for supplying power to motor M.But disclosed power hammer power supply mode is not limited thereto, and also can use ac-powered.Switch 7 is installed on the housing 2, is used to control the start and stop of motor M.Beating unit 6 comprises a hit piece 61, and these hit piece 61 basic horizontal are installed in the beating unit 6 through spring, and can do straight reciprocating motion therein.During operation, hit piece 61 impact the end-acted on objects such as securing member such as member such as nail, dowel or fragment of brick of end 611.Also comprise a cavity volume 63 in the beating unit 6, it has the internal diameter greater than general nail or other element diameter, so the nail of various sizes or other element all can be placed in the cavity volume 63.

Like Fig. 3 and shown in Figure 4, housing 2 contains rotation-rectilinear motion transmission mechanism, and this mechanism can convert rotatablely moving of motor M into the ballistic motion of hit piece 61.Motor M vertically is installed in the housing 2, and motor shaft X ' up passes to rotary power on the rotating shaft 35 that is supported on housing top through bearings at both ends through comprising the multi-stage gear transmission of bevel gear.Have a pair of skewed slot 36 on the rotating shaft 35,36 one-tenth openings of each skewed slot " V " font backwards.One impact block 31 is enclosed within on the rotating shaft 35, and this impact block 31 is roughly the cylinder of a hollow, and its inner cylinder face is provided with a pair of circular arc guide groove 37 relative respectively with two skewed slots, 36 positions, and the circular arc opening direction of each guide groove 37 is opposite with " V " shape skewed slot 36.Skewed slot 36 is at the bottom of the semi arch with guide groove 37.A pair of steel ball 38 lays respectively in the cavity volume that forms between corresponding skewed slot 36 and the guide groove 37, can relatively move along skewed slot 36 and guide groove 37.So can drive impact block 31 through the steel ball 38 that is positioned at skewed slot 36 when rotating shaft 35 rotates rotates.The a pair of convexity 32 that is oppositely arranged along diametric(al) is arranged on the excircle of impact block 31.After operating switch 7, motor M starts, and through the multi-stage gear transmission, driven rotary axle 35 rotates, and rotating shaft 35 drives impact block 31 through steel ball 38 again and rotates together thereupon.

As shown in Figure 4; One energy-storaging spring 40 is loaded between impact block 31 and the rotating shaft 35; The one of which end withstands on the step 351 of rotating shaft 35, and the other end withstands on the impact block 31, and the axial force of this energy-storaging spring 40 makes impact block 31 be in first axial location of relative rotation axi 35.In this first axial positions; Impact block 31 is done circumference and is rotated under the effect of rotating shaft 35 and steel ball 38; When impact block 31 turns to a certain position when making protruding 32 can touch hit piece 61, because hit piece receives the big resistance that temporarily can't overcome 61 this moments, the hit piece 61 temporary transient impact blocks 31 that stop rotate; Force impact block 31 to be displaced to one second axial location by first axial location energy-storaging spring 40 that gradually reduces; At this second place place, the convexity 32 of impact block 31 has been crossed hit piece 61, and braking is eliminated.Energy-storaging spring 40 begins to discharge its elastic potential energy, and the bounce of energy-storaging spring 40 not only makes impact block 31 axially reset towards primary importance, and passes through the acting in conjunction of skewed slot 36, guide groove 37 and steel ball 38, produces the high speed rotation that surmounts rotating shaft 35.As a result, the quilt of the convexity 32 bump hit pieces 61 on the impact block 31 impacts end 612, and hit piece 61 forms one-shot with high-effect moving linearly.After impacting completion for the first time, when impact block 31 turns to once more by hit piece 61 brakings, get into impulse period for the second time, and accomplish impact process afterwards in an identical manner.

To Fig. 9, in beating unit 6, also comprise a clamp mechanism 5 referring to Fig. 2, Fig. 5, it is used for clamping nail or other element.In the form and its main body 51 that is installed in this clamp mechanism 5 of this clamp mechanism 5 for clamping element 52a, 52b, 52c and 52d; Clamping element 52a, 52b, 52c and 52d have primary importance, i.e. clamping element closing position is like Fig. 6 and shown in Figure 8; Clamping element 52a and 52b are closed each other; Clamping element 52c and 52d are closed each other, form a clamping region, and nail or other element can be maintained at this zone.Clamping element 52a, 52b, 52c and 52d have the second place; Be the clamping element fully open position, like Fig. 7 and shown in Figure 9, clamping element 52a and 52b open each other fully; Clamping element 52c and 52d open each other fully; Form a release areas, hit piece can continue to impact nail through this release areas, till nail is hammered into workpiece fully.When clamping element was shown in an open position, nail or other element can be placed in the cavity volume 63, and then that clamping element is closed, nail or other element then are maintained at clamping region.Each clamping element is provided with groove, makes these grooves just can be meshed with the arc of nail shank, increases the contact area of the shank of clamping element and nail or other element, clamps better effects if.And because clamping element can be conditioned, the nail of different size or other element can clamped independently maintenances.And clamping element is opened, and nail or other element just break away from groove.

Certainly those skilled in the art can expect easily that also above-mentioned clamping element can be each or any combination of the claw, spring, magnet, screw or the chuck that are used for holding element.

Shown in Fig. 6-9; Sleeve pipe 8 is arranged to the cuboid of hollow, and sleeve pipe 8 is provided with the skewed slot group, is being respectively arranged with two skewed slots that are mutually symmetrical 81 and 82 on four faces up and down before and after it; The skewed slot of sleeve pipe front only is shown among Fig. 6, and the skewed slot of three faces is identical with the skewed slot of this face in addition.Skewed slot 81 and 82 also can be provided with all-in-one-piece, thereby forms " V " type groove.And skewed slot 81 and 82 is not linear skewed slot, but the skewed slot of broken line type, helps the stroke of reentrant bushing 8 like this, makes the more compact structure of complete machine.Here said broken line type skewed slot refers to nonlinear groove, comprises arc groove, groove that the straight line of two or many Different Slope forms etc. is arranged.The two ends that the drive part 53a of two clamping elements and 53b pass clamping element 52a and 52b and each drive part respectively are installed in respectively in the corresponding skewed slot 81,82 of sleeve pipe 8 upper and lower surfaces, and in addition two drive part 53c and the 53d two ends of passing clamping element 52c and 52d and each drive part respectively are installed in respectively in the corresponding skewed slot 81,82 of sleeve pipe 8 former and later two faces.Four drive parts form interlock; When clamping element is in primary importance; When being closing position; Four clamping elements clamp nail, and the two ends of drive part 53a lay respectively at an end of the corresponding skewed slot 81 of sleeve pipe 8 upper and lower surfaces, and the two ends of drive part 53b lay respectively at an end of the corresponding skewed slot 82 of sleeve pipe 8 upper and lower surfaces; The two ends of drive part 53c lay respectively at an end of the corresponding skewed slot 81 on two sides, sleeve pipe 8 front and back, and the two ends of drive part 53d lay respectively at an end of the corresponding skewed slot 82 on two sides, sleeve pipe 8 front and back.Four drive parts skewed slot relatively separately moves together; Like Fig. 7 and shown in Figure 9; When clamping element is in the second place, promptly during the fully open position, four clamping elements are opened each other; The two ends of drive part 53a lay respectively at the other end of the corresponding skewed slot 81a of sleeve pipe 8 upper and lower surfaces; The two ends of other drive part also lay respectively at the other end of skewed slot of two faces of each self-corresponding sleeve pipe, and hit piece 61 can therefrom pass and continue to impact nail, is hammered in the workpiece fully up to nail.It is understandable that it is the structure of one that drive part also can be arranged to clamping element.

During assembling; Earlier each clamping element is placed in the main body 51 of clamp mechanism; Respectively each drive part is passed clamping element separately then, a sheath 9 is installed on the outer surface of sleeve pipe 8 again, this sheath 9 can prevent drive part disengaging sleeve pipe 8 and drop out from the power hammer.Main body 51 is connected an end of cutting ferrule 10, and this main body 51 is with cutting ferrule 10 motions.It is understandable that drive part and clamping element also can be provided with the all-in-one-piece structure.

Shown in Figure 10-14, first bias unit provides with the form of spring 11, is used for sleeve pipe 8 is promptly impacted towards hit piece the direction biasing of element left; Thereby make clamping element be positioned at closing position; One end of this spring 11 is contained on the sleeve pipe 8, and the other end is contained on the convexity of cutting ferrule 10, when sleeve pipe 8 contacts with workpiece; The user need overcome the pressure of first bias unit, makes clamping element open.Second bias unit provides with the form of spring 12; Be used for cutting ferrule 10 is promptly impacted towards hit piece the direction biasing of element left; One end of this spring 12 is installed on the cutting ferrule 10; The other end is installed on the stop collar 13, and when the end face 51a of main body 51 contacted with workpiece, this main body 51 overcame the pressure of second bias unit with sleeve pipe 8 and moves.The 3rd bias unit provides with the form of spring 14; Be used for lining 15 is setovered towards the direction that hit piece impacts element; One end of this spring 14 is installed on the gear-box, and the other end is installed on the lining 15, when lining 15 contacts with workpiece; This lining 15 overcomes the pressure of the 3rd bias unit together with sleeve pipe 8 and cutting ferrule 10 and moves, and is hammered in the workpiece fully up to nail.

Above-mentioned spring can be compression spring or helical spring, and those skilled in the art can expect easily that also the bias unit of using other elasticity or having attraction, repulsive force replaces, and for example can replace spring 11,12 and 14 with magnetic part certainly.

In use, if clamping element is in the close position, as shown in Figure 2; Then the user can move right through the force sleeve pipe 8 that toggle 21 overcomes first bias unit 11, and this toggle 21 is installed on the housing 2, and it engages with sheath 9; The user pulls toggle 21 drive sleeve pipes 8 to the right and moves right together with sheath 9; Perhaps directly push sleeve pipe 8 and move right, when hearing " clatter " one, clamping element is opened fully; At this moment can nail be placed in the cavity volume 63; Discharge spanner 16 then and make clamped of nail keep independently, the power hammer is oriented to make nail adjacent with workpiece subsequently, loads onto to press switch 7 behind the power brick (not shown) and connect motor M and make hit piece 61 reciprocating motions.When the user pressed against the power hammer on the workpiece, the head of nail was impacted by hit piece 61 repeatedly, thereby little by little nail was inserted in the middle of the workpiece.When the user does not just want to stop to impact when clamping element is opened as yet; The user can pull toggle 21 drive sleeve pipes 8 to the right and move right together; Perhaps directly push sleeve pipe 8 and move right, make clamping element open each other, thereby make nail can break away from the power hammer.Be inserted into gradually in the process of workpiece at nail, shown in figure 10, when sleeve pipe 8 engaged with workpiece, the pressure that the user then need overcome spring 11 made clamping element open.This allows nail before being released, partly to get into workpiece.Like Figure 11 and shown in Figure 12, the lower end of sheath 9 comprises that at least one is protruding 91, and when this convexity 91 was pushed spanner 16 open, sheath 9 was pushed the convexity 101 of both sides on the cutting ferrule 10 open in housing, make main body 51 in housing, to slide.Shown in figure 12; When the end face 51a of main body 51 contacts with workpiece; Clamping element is in a fully open position, and the pressure that the user then need overcome spring 12 makes the head of a nail can pass through clamping element, and lining 15 also can continue to impact nail through clamping element with impulse member 61.Shown in figure 13, when lining 15 contacted with workpiece, the pressure that the user then need overcome spring 14 made lining 15 all the time around the head of a nail, prevented that the head of a nail is stuck in clamping element and opens fully in the slit that the back produces.Shown in figure 14, continue to impact nail then, hammered in the workpiece fully up to nail.

This clamp mechanism comprises a locking mechanism, and after nail was hammered in the workpiece fully, protruding 91 engaged with spanner 16, make sheath 9 be locked in the clamping element fully open position.Put a nail again in cavity volume 63, press lower ejector lever 16 then, make clamping element in cavity volume 63, clamp nail, repeat above-mentioned steps, then can carry out impacting the second time nail.The lower end of sheath 9 can also be provided with another convexity, makes sheath 9 can be locked in another position, and in this position, lining 15 exposes from sleeve pipe 8, increases the visuality of hit piece 61.At this moment, 611 positions of knocking that can be used as the power hammer are held in impacting of this hit piece 61, during work; Along with workpiece to be processed is knocked in the straight reciprocating motion of hit piece 61; As strike tenon, strike brick etc., realize the function expansion of this machine, and be not limited only to securing member is hammered in the workpiece.And those skilled in the art it is understandable that sleeve pipe 8 and sheath 9 usefulness transparent materials such as transparent plastic etc. are made according to present embodiment, also can increase the visuality of hit piece 61.When the user saw the particular location of hit piece 61, the user just can remove to knock workpiece to be processed with it when being used as power hammer.In addition, when the less nail of clamping, " V " connected in star that is provided with on sleeve pipe and the sheath also can increase the visuality of nail, person's operation easy to use.

The power hammer that the present invention discloses is not limited to described content of above embodiment and the represented structure of accompanying drawing.On basis of the present invention, change obviously, substitute or revise, all within the scope that the present invention requires to protect what made the shape of member wherein and position.

Claims (1)

1. a power hammer comprises that one impacts device, and described beating unit comprises hit piece and clamp mechanism; Described hit piece is used for the element that impacts repeatedly, and described clamp mechanism comprises clamping element, sleeve pipe, first bias unit and second bias unit, it is characterized in that: described sleeve pipe is provided with groove; Described clamping element slides in described groove, the primary importance of clamping element opposed slot, and clamping element is closed; The second place of clamping element opposed slot; Clamping element is opened, thus the direction that described first bias unit is used for impacting element towards hit piece to the sleeve pipe off-set sleeve of exerting pressure, described clamp mechanism also comprises a cutting ferrule; The directive effect that described second bias unit is used for impacting element towards hit piece is in described cutting ferrule, thereby to the cutting ferrule biasing clamping element of exerting pressure.

2. power hammer as claimed in claim 1; It is characterized in that described power hammer also comprises housing, motor, transmission mechanism and impacts assembly; Described motor vertically is installed in the described housing, and described transmission mechanism converts rotatablely moving of motor to said hit piece percussion action through bevel gear transmission and impact assembly.

3. power hammer as claimed in claim 1 is characterized in that at least two faces of described sleeve pipe are provided with groove, and described clamping element comprises drive part, and described drive part places in the described groove, and described drive part can move along described groove.

4. power hammer as claimed in claim 3; It is characterized in that described clamp mechanism comprises four clamping elements; Four faces of described sleeve pipe are provided with groove; Described clamping element comprises drive part, and described drive part places in the described groove, and described drive part can move along described groove.

5. power hammer as claimed in claim 1 is characterized in that described groove is set to broken line type.

6. power hammer as claimed in claim 3 is characterized in that described drive part is removably mounted on the described clamping element.

7. power hammer as claimed in claim 3 is characterized in that described drive part and described clamping element are provided with all-in-one-piece.

8. power hammer as claimed in claim 1 is characterized in that described clamping element comprises each or any combination of the claw, spring, magnet, screw or the chuck that are used for holding element.

9. power hammer as claimed in claim 1 is characterized in that when described clamping element is positioned at open position, forms a release areas, and described hit piece can be through described release areas.

10. power hammer as claimed in claim 9 is characterized in that described clamp mechanism comprises a lining, and described lining can be through described release areas.

11. power hammer as claimed in claim 10 is characterized in that described clamp mechanism comprises the 3rd bias unit, the direction that described the 3rd bias unit impacts element towards the hit piece described lining of setovering.

12. power hammer as claimed in claim 1 is characterized in that described clamping element can interlock.

13. power hammer as claimed in claim 1 is characterized in that described clamp mechanism comprises a locking mechanism.

14. power hammer as claimed in claim 13 is characterized in that described locking mechanism comprises a spanner and at least one convexity.

15. power hammer as claimed in claim 14 is characterized in that described clamping element is positioned at open position after one of them described convexity and the locking of described spanner.

16. power hammer as claimed in claim 14 is characterized in that described lining exposes after one of them described convexity and the locking of described spanner from sleeve pipe.

17. power hammer as claimed in claim 1 is characterized in that described sleeve pipe is provided with a sheath.

18. power hammer as claimed in claim 17, thereby it is characterized in that a toggle makes described toggle and described sheath move with described sheath joint.

19. power hammer as claimed in claim 17 is characterized in that described sheath and/or described sleeve pipe made by transparent material.

20. power hammer as claimed in claim 17 is characterized in that described sleeve pipe and/or described sheath are provided with groove.

Images