Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02555585 2006-08-08
FIELD OF THE INVENTION
[0001] The present invention relates to drill attachments, and
more particularly to drill attac2unenCs that cause a hammering
action.
BACKGROUND OF THE INVENTIC)N
[0002] Hammer drills are well known and are typir_ally tlsed, even
by hoine cz-afLstaeri, to drill holes in relatively hard substances,
such as concrete and the like. Such hammer drills typically have
a'rot'ating spindle that drives the drill chuck. A fixPd disc
having a rearwardly facing toothed surface is secured to the
rotations spindle. A movable disc having a forwardly facing
toothed surface is selectively Qngageable with the rearwardly
facing toothed surface of the- fixed disc so as to provide the
,. ,
hammer drill function. Although the apparatus does work, it
presents a serious drawback in that the impact created by the
engagement of the two toothed surfaces is diL=ecLed forwardly
throuqh the drill bit and also back through the drill itself, as a
reaction force. Accordingly, the bea.ri,ngs of the drill tend to
wear excess.ivel y, which is highly undesirable. P'urthex, it is well
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known that there can be significant heat build with prior art
hammer drills.
[0003] Such hammer drills, also known as percussion drills, can
be found in for example United States Patent 2, 942, 852, issued June
28, 1960 to Muthman and United States Patent 5,653,294, issued
August 5, 1997 to Thurler.
[0044] United States Patent 4,450,919, issued May 29, 1984 to
Cousineau discloses a. drill attachri!ent for use with a conventi_onal
el.ectric drill. This dri1l attachment provides a hammering and
drilling acti,on so that a conventional drill may be used to drill
into hard substances. The drill attachment c-omprizes a hammer
assembly having a rearward case and a forward chuck assembly. A
rotating spindle is mounted within the case and has a reciprocating
spindle mounted in the front end thereof. The rotating spindle
drives a drill chuck within the chuck assembly via the
, ~. ,.
reciprocating spindle. A rotating c1u-L-ch plate mounted on the
reciprocating spindle rotates w:i,th the reciprocating spindle.
Teeth on the rotating clutch plate engage cooperating teeth on the
stationary clutch that is securely mounted on the case. A
removable handle connected to the case permits the case, and
therefore the stationary clutch, to be selectively moved forwardly
such that the teeth of the stationary clutch engage the teeth of.
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the rotating clutch plate, to thereby impart the hammering function
to a drill bit retained within the bit chuck. As is well known,
the friction generated by the two sets of co-operating teeth
frictionally engaging each other, i;, inefficient in terms of energy
transfer and causes unnecessary heat buildup.
[0005] It is a further object of the preserit i.rxvention to
prdvide a hammer drill bit chuck attachment.1
[0006] IL is yet a further object of the present invention to
r= 9=
provide a hammer drill bit chuck attachment that is inexpensive to
manufacture.
[0007] It is yet a further object of the present invention to
provide a hammer drill bit chuck attacbzaent that is robust.
[,0008] . it is yet a further object of the present invention to
provide a hammer drill bit chuck attachment wherein heat build up
is minimized.
[0009] It is yet a further object of the present invention to
provide a hammer drill bit chuck attachment whereiri an plec:tr. i c
drill used in conjunction with the hammer drill bit chuck
attachment can be operated at lower rotatiQnal speeds.
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[00010] It is yet a further object of the present invention to
provide a hammer drill b.i.t chuck attachment that is operable
without manual actuatiori in an operatively engaged position.
[00011] It is yet a further object of the present invention to
provide a hammer drill bit chuck attachmen't wherein more power is
available tio be transferred to a drill bit from an electric drill
used in conjunction with the hammer drill bit chuck attachment.
SUMdKARY OF THE INVENTION
[00012] In accordance with one aspect of the present invention
there is disclosed a novel hammer-action attachment for use with a
~ e
conventional electric drill. The hammer-action attachment
comprises,.a mairi shaft having a forward drila. chuck end po 'rtion and
a rearward shank portion, and defines a longitudinal axis. An
impact member is sectire.ly mounted in longitudinal force
transmitting relatiori on L'he main shaft for rotation therewith
about the Iongitudirial axis. An actuator mechanism is mounted on
the main shaft for free rotation of the main shaft with respect to
the actuator m.echanism and for longitudinal sliding movement of the
actuator mecharii5m along the main shaft between a forwardly
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displaced position and a rearwardly displaced position. A drill
engaging member is securely connected to the actuator mechanism and
extends rearwardly from the actuator mechanism for engagement with
the electric drill. The drill engaging member biases the actuator
mechanism into force transrcmitting engagement with the impact
member, and precludes rotatidnal movement about the longitudinal
axis of the actuator mechanism with respect to the electric drill.
Kotati.on of the main ~haft and impact member about the longitudikal
axis wtien the actuator mechanism is biased into force transmitting
engagement with the impact member, causes the acLuator mechanism to
move in a reciprocating motion bPt_ween the forwardly displaced
position and the rearwardly d%splaced position, and transmits
impact forces forwardly along the longitudinal axis to the main
shaft.
[00013] Qther advantages, features and characterisLics of the
present invention, as welcl as methods of operation and functions of.
the related elemenLs of the structure, and the combination of parts
and economies of manufacture, will become more apparent upon
consideration of the following detailed description and the
appended claims with reference to the accompanying drawings, the
latter of which is briefly described herein below.
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BRIEF DESCRIPTION OF THE DRAWINGS
[00014] The novel features whi.ch are believed to be
characteristic of the hammer-action attachment for use with a
coriveriLional electric drill according to the present invention, as
Lo its structure, ozganization, use and method of operation,
together with further objectives and advantages thereof, will be
better understood from the .f.ol~owi,ng drawings in which a presently
preferred embodiment of k.he invention wi],l now be illustrated by
way of example. It is expressly understood, however, that the
drawings are for the purpose of illustration and description only,
and are not intended as a definition of the limits of the
inventian. In the accompanyinq drawings:
[00015] Figure 1 is a perspective view of the first preferred
~. ,.
embodiment of the hammer-action attachment for uae with a
conventional electrir. drill,according to the present invention;
[000161 Figure 2 is a top plan view of the first preferred
embodiment hammer-action attachment for use with a conventional
electric drill of Figure 1;
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[00017] Figure 3 is a side elevational view of the first
preferred embodiment hammer-actiorl attachment for use with a
conventional electric drill of Figure 1;
[00018] Figure 4 is a frotiL end view of the first preferred
embodiment hammer-actioti attachment for use with a conventional
electric drill of Figure 1;
[00019] Figure 5 is a back end view of the first preferred
embodiment hammer-action attachment for use with a conventional
electric drill of Figure 1;
[00020] Figure 6 is a partly exploded perspecLive view of the
first preferred embodiment hammer-action attachment for use with a
convpntiona7 electric drill of Figure 1;
[60021] Figure 7 is a sectional side elevational view of the
fi.r..st preferred embodiment hammer-action attachment for use with a
conventional electric drill of Figure,.l, taken along section line
7-7 of Figure 4;
[00022] Figure 8 is a secLional top plan view of the firsL
preferred embodiment hammer-action attac,hment for use with a
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conventional electric drill of Figure 1, taken along section line
e-~3 of Figure 4;
[00023] Figure 9 is a partly exploded perspective view of the
first preferred embodiment hammer-action attachment for use with a
conventional electric drill of Figure 1, with the plastic overmold
removed for the sake of clarity;
c
[00024] Figure 10 is a side elevational of the first preferred
emPodiment hammer-action attachment for use with a conventional
eleGtric dri.l], of Figure 1, with the p].astic overmold removed for
the sake of clarity;
[00025] Figure 11 is a perspective view of the plastic overmold
used in the first preferred embodiment hammer-action attachment for
use with a conventiorial electric drill of Figure 1;
[000261 Figure 12 is a side elevational of the plastic overmold
used in the first preferred embodiment hammer-action attachment for
use w.i.th a conventional electric drill of Figure 1;
[00027] Figure 13 is a sectional side elevational of the plastic
overmold used in the first preferred embodiment hartutzer-action
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attachment for use with a conventional electric dr.ill of Fiqure 1,
taken along section line 13-13 of Figure 11;
(000281 Figure 14 is a perspective view of the locking collar
used in the first preferred embodiment hamme.r-action attachment for
use with a conventional electric drill of Figure 1;
[00029] Figur= 15 is a perspective view of the dri'll engagi.ng
member used in Lhe first preferred embodiment hammer-action
attachment for use with a conventional electric drill. of Figure 1;
[00030] Figure 16 is a side elevational view of l:he drill
engaging member used in the first preferred embodiment hammer-
action attachment for use with a conventional electric drill of
Figure 1;
[00031] Figuxe 17 is a sectional side el.evational. view~ of the
drill engaging member used in the first preferred embodiment
hammer-action attachment for use with a conventional electric drill
of Figurc 1, taken along section line 17-17 of Figure 15;
[00032] Figure 18 is a sectional top plan view of tho drill
engaging member used in Lhe first preferred embodiment hammer-
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action attachment for use with a conventional electric drill of
Figure 1;
[00033] Figure 19 is a perspective view of the impact member used
in the first preferred embodiment hammer-action attachment for use
with a conventi_onal electric drill of Figure 1;
[00034] Figure 20 i.'s a perspective view of the drill engagi,ng
member used in the first preterred embodiment hammer-action
attachment for use with a conventional electric dril3, of Figure 1;
[000351 Figure 21 is a back end, elevational view of the drill
engagi.ng member used in the first preferred embodiment hammer-
action attachment for use with a conventional el.ectric: drill of
Figure 1;
[00036] Figure 22õ is a i-sectional side elevational view of.. the
drill engaging member used in the First preferred embodiment
hammer-action attachment for use with a conventional electric drill
of Figure 1, taken along section line 22-22 of F'igure 21;
[00037] Figure 23 is a perspective view of the substantia.]1.y
cylindrical core of the actuator mechanism used in the first
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preferred embodiment hammer-aetion attachment for use wiGh a
conventional electric drill of Figure 1;
[00038] Figure 24 is a side elevational view of the subsf;dnti.ally
cylindrical core of the actuator mechanisza used in the first
preferred embodiment hammer-action attachment for use with a
conventional electric drill of Figure 1;
[00039] Figure 25 is a perspective view of the -cntact rinq of
the actuator mechanism used in the first preferred embodiment
hammer-action attachment for use with a conventional electric drill
of Figure 1;
[00040] Figure 26 is a perspective view of the main shaft of the
actuator mechanism used in the first preferred embodzment hammer-
action attachment for use with a convenkionaJ. electric drill of
Figure 1;
1000411 Figure 27 i.s a side elevational view of the first
preferred embodiment hammer-action attachment for use with a
conventional electric drill of Figure 1, with the actuator
mechanism in an forwardly c3isplaced position;
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[00042] Figure 28 is a side elevat;ional view of the first
preferred embodiment hammer-action attachment for use with a
conventional electric drill of Figure 1, with the actuator
mechanism in a rearwardly displaced position;
[00043] Figure 29 is a perspective view of the second preferred
embodiment of the hammer-act.i.on attachment for use with a
conventional electric drill according to the present invention;
[00044] Figure 30 is a sectional top plan view of the second
preferred embodiment of the hammer-action attacrunent for use with
a conventional electric drill of Figure 29, taken along section
line 30-30 of Figure 29;
[00045] Figure 31 is a sectional side elevational view of the
second preferred embodiment of the hammer-action attachment for use
with a conventional electric drill of Figiire 29, taken along
section line 31-31 of L'igure 29;
[00046] Figure 32 is a front end view of the second preferred
embodimenl; of the hammer-action attachment for use with a
conventional electric drill of Figure 29;
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(00047} Figure 33 is a perspective view from the back of the
handle m.ember used in the second preferred embodiment of the
hammer-action attachment for use with a conventional electric drill
of Figure 29;
[00048] Figure 34 is a sectional top plan view of the handle
member used in the second preferred embodiment of the hammer-action
attactiinent for use with a conventional electric drill according to
the present inventiorl, taken aJ.ong section line 34-34 of F'igure 33;
and,
[00049] Figure 35 is a sectional side elevata,onal view of the
handle member used in the second preferred embodiment of the
hammer-action attachment for use with a conventional electric drill
of Figure 29, taken along section line 35-35 of Figure 33.
,. .
DETAILED DESCRIPTION OF TTIE PREFERRED EMBODIMENTS
(00050] Referring to Figures 1 through 35 of the drawings, it
will be noted that Figures Z through 28 illustrate a first
preferred einbodiinent csf the hammer-action attachment for use with
a conventional electric drill of Ltie present invention, and Figures
29 through 35 illustraLe a second preferred embodiment of the
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hammer-action attactunent for use with a conventional electric drill
of the present invention.
[00051] Reference will now be made to Figures 1 through 28, which
show a preferred embodiment of the hammer-action attachment for use
with a conventional electric drill of the pr=esent invention, as
indicated by general r-elerence numeral 20, for use with a
conventional e7ectric drill 28 (shown in Figures 27 and'28).
[00052] The hammer-action attachment for use with a conventional
electric drill 20 comprises a main shaft. 30 having a forward drill
chuck end portion 33 and a rearward shank portion 34 that is
preferably hexagonal in cross-section. The main shaft 30 defines
a longitudinal axis "L" about which the main shaft 30 rotates.
[00053] A conventional drill bit chuck 35 is mountabl.e on the
forward dril.l chuck eiid portion 33 of the main shaft 30 for
rotatiori therewith, and comprises three movable jaw members 36 that
receive and retain a conventional drill bit 29 therein. The drill
,. ,.
bit chuck 35 has a threaded bore hole 39a that receives the co-
operating threaded forward drill chuck end portion 33 in secure
engagement. Fundamentally, the hammer drill bit chuck attachment
20 comprises a main shaft 30, an impact member 40, an actuator
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mechanism 50, and a drill engaging member 70, as will be described
in greaLer detail below.
[00054] The impact member 40 is securely mounted in fixed
relation on the main shaft 30, so as to be in longitudinal force
transmitting relation, for rotation therewith about the
longituCinal axis "L". The impact member 40 has a rearwardly
facing impact surface 42 that in the first preferred en-bodiment as
illustrate comprises a plurality of teeth 44. Other types and
shapes of impact surfaces have also been found to be suitable..
[00055] The actuator mechanism 50 is mounted on the main shaft 30
for free rotation of the main shaft 30 with respect to the actuator
mechanism 50 and for longitudirial sliding movement of acLuator
mechanism 50 along the main shatt 30 between a forwardly displaced
position, as can be best seen in Figure 27, and a rearwardly
displaced position, õas can be best seen in Figure 28. A roller
bearing 57 disposed aL the rear of the substantially cylindrical
core 53 ensures a cl.ose but non-binding fit ori the rearward shank
portion 34 of the main shaft 30. The actuator mechanism 50 engages
the impact surface 42 of the impact member 40 when the actuator
mechanism 50 is in its forwardly displaced posi,tion.
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[00056] The actuator mechanism is retained on the rearward shank
portion 34 of the main shaft 30 by means of a G"-cl.ip 58 securely
engaged 3,n an annulax= slot 36 in the rearward shank portion 34.
[00057] The actuator mechanism 50 has at least one roller member
52 freely rotatably mounted thereon by means of suitable threaded
fasteners 52a, and in the first preferred embodiment as
illustrated, the at least one roller member. 52 comprises three
roller members 52, each freely rotatably mounted on the actuator
mechanism 50. Preferably ..the three roller members 52 are
substantially equally radially spaced around the actuator mechanism
50, and around the longitudinal axis "L". When the actuator
mechanism 50 is bi.ased. in to forced transmitting cngagement with
the impact member 40, by the drill engaging member 70, the three
roller members S. are in force transmitting engagement with the
~. .
impact surface 42 of the impact member 40, as the mai.n shaft 30
rotates with respect to the actuator mechanism 52. }
[00058] The actuator mechani.sm. 50 comprises a substantially
cy].indrical main body member 54 that preferably coiaprises a plastic
overmold 51 molded over a substantially cylindrical core 53. The
aubstantial],y cylindrical main body member 54, and specifically the
plastic overmold 51, has a male-threa.ded exterior surface 55.
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[000591 The plastic overmold 51 also has a forwardly extending
annular portion 51a. The three roll.er members 52 of the actuator
mechanism 50 are covprPd by the forwardly extending annular poz=t:ion
51. As can be seen in the figures, when the actuator mechanism 50
in its forwardly displaced position, rhe .rol,].er members 52 engage
the impact surface 42 of the impac;L member 40, as the main shaft
rotates with respec:t to the actuator mechanism 50.
[00060] The hammer-action attachmerit 20 further comprises a drive
collar 60 having a throughpassage 62.. The drive collar 60 is
connected in freely slidable relation to the actuator member 50, to
permit longitudinal movement of Lhe actuator member 50 on the
rearward shank portion 34 of the main shaft 30. The drive collar
60 extends rearwardly from the actuaLor member 50 to receive the
rearward shank portion of 34 of the main shaft 30 in the
throughpassage 62. 'I'he drive collar 60 is hexagonal in cross
section so that it can be gripped more securely in the chuck 23 of
the electric drill 22, which is cspecially a.mportanL in an
electric drill havi.ng a keyless chuck. Further, thP throughpassage
62 is hexagonal in cross-section so that is does not rotate around
the rearward shank portion 34 of the main shafL, and thereby can
transmit rotational force from the electric drill 22 to the main
shaft 30.
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[00061] The first preferred embodiment hammer-action attachmerit
20 also comprises a drill engaging member 70 securely connected to
the actuator mer.hanism 50. The drill engaging member 70 extends
rearwardly from the actuator mechanism SO for engagement wiCh the
electric drill 22. The drill engaging member 70 biases the
actuator mechanism 50 in to force transmitting engagement with the
impact surface 42 of the impact member 40, and precludes rotational
movement about the longitudinal axis "L" of the actuator mechanism
50 with respect to the electric drill 22.
,. ,
[00062] The drill engaging member 70 comprises a front collar 72,
a rear collar 74, a first ariti member 71 and a second arm member 72.
The first and second arm member 73., 72 extend between the frorit
collar 73 and the rear collar 74. The first and second arm mQmber.
71., 72 are longitudinally flexible, so as to provide for the
bia5ing action of the drill engaging member 70, and are preferably
made from ABS plastic (acrylonitrile butadiene styrene).
[00063] The front collar 73 of the drill engaging member 70 has
a cooperating female threaded interior surface 77 that threadibly
engages the male threaded exterior surface 55 of the substantially
cylindrical main body member 54, thereby permitting the front
collar 73 of the drill engaging member 70 to be longitudinally
adjustable on the substantially cylindrical main body member 54 of
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the actuator mechanism 50. In this manner, the overall length of
the first preferred embodiment hammer-action attachment 20 is
adjustable, to accommodate various sizes and shapes of conventional
electric drills.
[00064] '1'he hammer-action attactunent 20 further comprises a
locking collar 78 having a co-operating female-threaded interior
surface 79 that threadibly engages the male-threadeci exterior
surface 55 of the substantially cylindrical main body member 54 of
the actzaator mechanism 50. The locking collar 78 is rotated to
abut txgainsL the front collar 73 of the drill engaging member 70,
to t,hereby lock the drill Gngaging member 70 in place on the
substantially cylindrical main body member 54 of the actuator
mechani,sm 50.
[00065] The rear collar 74 of the drill engaging member 70 has a
high friction surface 75 at its back and, to preclude slippage w,ith
respect to the electric drill 22. The high friction surface 75 is
part of a high friction ring member 76 that is preferably made from
poly vinyl chloride.
[00066] xotation of the main shaft 30 and the impact member 40
about the longitudinal axis "L", when the actuator mechanism is
biased in to force transmitting engagement with Lhe impact member
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40 by the drill engaging member 70, causes the actuator mechanism
50 to move in a reciprocating motion between its fo.r,wardiy
displaced position and its rearwardly displaced position, and
Lransmits impact forces forwardly along the longitudinal axis "L"
to the main shaft 30, thereby providing a hammer-action to the
drill bit 29 in the chuck 35.
[000671 Reference will how be made to Figures 29 through 35,
which show a second preferred embodiment of the present inventian.
In the second preferred embodiment, indicated by the general reference
numera3. 220, the hammer-action attachment 220 comprises
a hand gripped 270 having an inLernal threaded passage way 272 that
threadibly engages the male-threaded exterior surface 55 of the
substantially cylindrical main body member 54 of the actuator
mcchanism. This h.and grip 270 permits manual manipulation of the
actuator 50 in to engagement with the impact mHmber 40, and might
be used when it is desirable to select between a hammer drilling.
~ ~.
-iction and a conventional drilling action.
(000681 It can readily,be seen that the hammer-action attachment
for use wiLh a conventional electric drill, according to the
preserit: invention, permits a conventional electric drill to
function as a hammer drill, when the hammer-action attachment is
used with a conventional electric drill. It has been found that
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using the combination of the hammer-action attachment according to
the present invention with a conventional electric drill, holes can
be drilled into masonry and the like even Faster than with most
hammer drills, evezi those costing several hundred dollars.
[00069] Further, it has been found that with the hammer drill bit
chuck attachment 20 of the present invention, there is reduced
friction, reduced heat build up, reduced wear and improved dri.].1.ing
performance compared with conventional hammer drills, which have
two sets of impacting steel teeth used to perform the hammering
function_ Heat build up is of particular concern under IEC
60745-1:2001, as adopted by UL, CSA and other natiorial governing
bodies regulating safety in hand held power tools and accessories.
pn electric drill using the present invention experiences very
minimal 1055 of spcod due to the reduced Lriction between the
roller members bz and the impact meamb.er 40. Accordingly, the
rotational energy is directed to the actual longitudinal vibration,
and not to losses due to friction and heat. This is important for
being able to achieve the maximtun poss.ib].e speed with a drill, and
also for reduced wear of the hammer drill bit chuck attachment of
the present invention and art electric drill being used. In
contrast, an electric hammer drill actually operates at: a
significantly reduced rotational speed compared to the maximum.
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rotational speed of the drill, due to the ~riction of the steel
teeth.
[00070] As can be understood from the above description and from
the accompanying drawings, thc present invention provides a hammer-
action attachment for use with a conventional electric drill that
is inexpensive to manufacture, that is robust, wherein the
frequency and amplitude of impacts can be adjusted or selected,
wherein heat build up is minimized, whereiri an electric drill used
in conjunction with the hammer drill bit chuck attachment can be
operated at lower rotational. speeds, and whexel,n more power is
available to be transferred to a drill bit from an electric drill
used in conjunction with the hammer drill bit chuck attachmpnt, all
of which features are unknowri in the prior art.
[00071) Other variations of the above principles will be apparent
to those who are kriowledgeable in the ficld. of the invention, arid
such variations are considered to be within the scope of the
present invention. I'urther, othe-r znodificatior:s and alterations
may be used in the desiqn and manufacture of the hammer drill bit
and hammer drill bit chuck attachment of the present invention
without departing from the spirit and scope of the accompanying
claims.
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