close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2408485

код для вставки
Oct. 1, 1946.
A. R. scHwARzKoPF
2,408,484
PERCU‘S S IVE TOOL
Filed Nov. 6, 1943
32
5o
26
24.
5'/
V20
/0
_2l
50
24»
2l
58
22
25
55
17
56
\
\\
. |_
16;Í
1:5 -
/4. ~
l!
|
J
7
Patented Oct. 1, 1946
2,408,484
UNITED STATES PATENT OFFICE
2,408,484
PERCUSSIVE TOOL
y Arthur R. Schwarzkopf, Chicago, Ill., assigner to
Wodack Electric Tool Corporation, Chicago,
Ill., a corporation of Illinois
Application November 6, 1943, Serial No. 509,311
1
8 Claims. (Cl. Z55-42)
The invention relates to power operated ham
mers or percussive tools and more particularly to
2
to Figs. 1 and 2 but showing the impact member
in its extreme advanced position.
portable tools in which the power is supplied by
Fig. 4 is a fragmentary sectional view of a mod
a rotary motor.
iñed form of the tool.
Fig. 5 is a perspective view of the actuating cam.
In tools of the above general character' a heavy 5
Fig. 6 is a perspective view of the cam follower
power spring is utilized to drive the reciprocatory
which is adapted to cooperate with the cam shown
impact member against a tool bit such as a star
drill which is loosely held in a socket provided
in Fig. 5.
for that purpose. Retraction of the impact mem
While the invention is susceptible of various
ber to condition the spring for action is effected 10 modifications and alternative constructions, I
by the motor through the medium of an actuating
have shown in the drawing and will herein de
mechanism usually in the form of a cam. In
scribe in detail the preferred embodiment, but it
normal operation when the tool bit is held firmly
is to be understood that I do not thereby intend
against a workpiece, substantially the entire force
to limit the invention to the specific form dis
imparted to the impact member by the power
spring is absorbed by the tool bit. When the
motor is run idly, that is, Without a tool bit in the
socket or when the pressure on the bit is relieved,
the shock of stopping the impact member must
be absorbed within the tool itself. In percussive 20
tools as constructed heretofore, the shock is or
dinarily taken by the actuating mechanism or
closed, but intend to cover all modifications and
alternative constructions falling within the spirit
and scope of the invention as expressed in the
appended claims.
The improved percussive tool, in the form se
lected for illustration, comprises generally an
elongated cylindrical casing or barrel Ill prefer
ably in the form of a hollow casting. At one
end, the barrel is provided with a socket II for
the same.
receiving the shank of a tool bit While the other
One object of the invention is to provide novel 25 end is suitably shaped so that it may be friction
means for effectually absorbing the shock of the
ally clamped to the spindle hub of an electric
impact member without subjecting the actuating
drill I2 or similar power driven tool. Supported
mechanism to excessive wear or strain when the
within the barrel coaxial with the socket II is a
motor is run idly.
reciprocable impact member or plunger I3. As
Another object is to provide novel means for
herein shown the socket II is formed in a plug
absorbing the shock of the impact member which
I4 threaded into the barrel and its inner end is
permits the full driving power of the power spring
splined for coaction with corresponding splines
to be utilized in the normal operation of the tool.
I5 on the impact member thus providing a slid
Still another object is to provide a percussive
ing «bearing for the member while effectually
tool of novel and advantageous construction in
holding it, against rotation.
which the power spring is enabled to effectually
The impact member I3 is yieldably held in a
absorb the shock of the impact member when
centered position in the housing by means of an
the tool is run idly.
extensible power spring I6. As herein shown,
It is also an4 object of the invention to provide
a percussive tool in the nature of an attachment 40 the spring I6 is arranged to act -between the im
pact member and a `pair of spaced abutments I1
suitable for use with an ordinary portable elec
and I8 rigid with the barrel Ill. In the exemplary
tric drill or the like which is simple and relatively
tool, the abutment I'l is formed integrally with
inexpensive to manufacture, which is rugged and
the barrel I0 While the abutment I8 is formed
~ durable in construction and Which is enicient in
operation.
45 by the inner end of the plug I4. The force of
the spring is exerted on the impact member
Other objects and advantages of the invention
through the medium of a collar I9 interposed
will become apparent from the detailed descrip
between the end of the spring and an upwardly
tion of the preferred embodiment illustrated in
facing shoulder 2D formed on the member adja
the accompanying drawing in which:
Figure 1 is a longitudinal sectional view of a 50 cent the splined end. Movement of the impact
member toward the socket under the action of
percussive tool embodying the features of the
cam resulting in excessive wear or damage to
invention.
Fig. 2 is a sectional View similar to Fig. 1 show
ing the impact member in retracted position.
Fig. 3 is a fragmentary sectional view similar
the spring I6 isk thus limited by engagement of
the collar I9 with the fixed abutment I8, the
shoulder and abutment being located so that the
end of the plunger projects into the socket II
55,408,434
3
a sufficient distance to engage the shank ofthe
cam member to bear against a collar 2l loosely
tool bit held therein.
mounted on the plunger below the cam follower
.
'
Suitable actuating means is provided for
periodically retracting the plunger i3 from the
socket II against the forceV exerted by the spring
I'o‘ and for releasing the member for impact with
the tool bit. The actuating means is arranged
to be driven by the motor of the drill I2 to which
the tool is attached and, >as herein shown, com
prises a rotary cam member 2l, preferably of
cylindrical form. The cam member is formed
with an end wall 22 adapted to rest on an anti-`
friction thrust bearing 23 seated in a counter.
:bore
abutment
in the
Il. barrel l? immediately above
As will be seen by reference to.`
Fig. 5, the open end of the cylindrical wall of
the cam member 2l is shaped to provide two inéf
clined cam surfaces Ztl each extending throughl
26, A groove Bâ in the face of the collar prevents
binding of the same `on the impact member in theY
event that the collar is deformed by theV pound
ing of the cam follower thereon.
The sleeve .35 and collar 3l" are dimensioned
and arranged so that the- follower 25 rests on the
upper surface of the collar and the follower varms
Z‘l are held out of engagement with the cam sur
faces Zfi when the impact member I3 is in its
v
normal rest position as shown
in Fig. 1.A As the
cam is rotated, the cam surfaces 2li engage the
El thus retracting the impact
member from the Ysocket and compressingrthe
spring it between the collar It and Vflange 36
ofY the sleeve 35. When the cam surfaces lride
out »from under the follower arms, the spring I5
approximately 180° and terminating in abrupt
.faces 2.5.
advances the impact member rapidly toward the
For coaction with the cam member, a cam
socket.
ïn the event that rno resistance is pre
follower 25 is threaded on the upper end of the
sentediosuoh movement, as byY a tool bit,- the
inertia- `of the _impact’memgbe'rrcarries it beyond
impact member i3; The cam follower, as shown
the` normal restposition and the impact' ofthe
in Fig. 6, comprises a collar having arms 2ll pro#
jecting radially from opposite vsides for engage
ment with the cam surfaces 2li. Since the plunger
I3 is held against rotation by its splined connecä
member IS falls lliBOn the collar 31 instead of on
tbe oem and follower'` arms 2l.. Tbe'foree'of the
tion with the plug i4, rotation of the cam mem
ber ZI is thus effective to retract the follower
25 and impact member I3 against the force of
the power spring IE. When the cam surfaces
24 ride out from under the follower arms, the
abrupt faces 25 of the cam member permit the
plunger to advance rapidly under the actio-vi of
the spring i6 and thus deliver a powerful im#
vpower spring I6.
. The action above described takes place only
after the power `spring `has expended its power
to advance the impact member as determined by
the engagement of the collar i9 with' the nxed
pact to the tool bit.
'
Y
Rotation of the cam mem-ber 2l is eiîecîed
through the medium of a power transmitting c'_'-n
nection with the driven spindle of the drill I2.
rí‘his connection, as herein shown, comprises a
cup-shaped head 3i! enclosing the cam member
and threaded thereto as shown in Figs. 1_4. At
its upper end, the head 3E is provided with an
impact is transferred from the Collar through the
sleeve 35 and fiange 36 to the upper' end 'of the
abutment i8. The power _spring thus brings .the
impact member to a cushioned stop .and absorbs
the shock incident thereto without sacriñce‘o'f
normal operating efficiency. In this way a single
spring is enabled to 'function both >as 'the Vdriver
for the 'impact member in the normal operation
of the tool and as a buffer or shock absorber when
the tool .is run idly. The use of a single spring
for this purpose materially Simp-lines the con
struction of the tool and correspondingly reduces
axially projecting shank 3i adapted .to be. se-`
its cost, Moreover, the operating efficiency. of the
powerspring is not impaired since the shock ab-A
cured in a colletchuck 32 or the like fast on
sorbing. action takes place only after the spring
the end of the drill spindle. The sides of the
barrel ISB are preferably‘cut away adjacent the
head 353 and chuck 32 to provide kconvenient ac-cess to these parts V`for connecting and discon»
has advanced the'impactr member to the full ex
tent permitted in normal operation.
'
’
' The modified construction shown in Fig. 4 is
similar in general to that above described except
-
that a sleevev ¿lil which corresponds in function to
In the normal operation of the tool, that is,
when the tool bit is held against the work with
the sleeve 35 is formed with an »integral ñange
or coilar 4I at its upper end for engagement ,with
the lower face of Ythe, camrffollowerlâ.' YThis
necting the tool and drill.
-
Y
a substantial amount of pressure, the impact of
the member I3` is absorbed by the tool bit. How-_
ever, when the tool is runidly either without a
tool bit in the socket or when the bit is not held
ñrmly against the work, allora part of the im
pact of the member I3 must be absorbed within
the tool itself. ln accordance with the'present
ñange is recessed as' at 42 to prevent binding- on
the plunger inthe eventI thatfthe> flaríge’isfde-j
formed by the pounding of the fo1lower.` l¿it .lits
lower end, the sleeve 40 abuts `against a washer
43 looselymounted on the impact member I3' and
interposed between the abutment ll and the
invention, advantage is taken of the fact that 60 upper end of the power spring 16. In this in-Y
the driving action of thepower spring is ter
stance, the impactof‘the memberlt is taken by
Aminated at a definite point in the advance oí
the ñange _4| and transferred through the sleeve
the impact member to utilize the power Spring
4t and _washerfiiä to the power spring which'thus
brings the plunger to a cushioned stop without
itself to absorb the impact of the member after
imposing unnecessary strains on the cam or lon
the driving force of the spring has been expended.
the parte of the follower coacting therewith.
To enable the spring I6 to perform its shock
. It will be apparent V_from theforegoing that
absorbing function, the impact member I3 is fit1
the invention provides a percussive tool of novel
ted with a sleeve 35;, which may also be referred
and advantageous construction embodying im
to as _a motion- or force-transmitting member,
having at one end a peripheral ilenseâß inter-l
posed between the abutment Il and theupper
_end of the power Spring l5, The sleeve is Supl@
ported and guided for axial sliding movement in
a central bore in the'abutment Il and it extends
proved means for absorbing vthe vimpact of _ the
impact member when the‘tool is run id1y_„By
reason of the improved construction, the'power'
spring -itself is enabled to function as va buffer
or shock absorbing means >without in the least
through the bearing 23 and end wall 22 of the 75 impairing its normal operating efficiency.' The
2,408,484
5
6
improved tool is simple and relatively inexpensive
the member to `the action of the spring, and
to manufacture, very rugged and durable in con
means reciprocable- with said member engage
able with the other end of the sleeve to interrupt
the outward movementv of the member by said
struction and eñicient in operation,
ï claim as my invention:
l. A hammer attachment for rotary drills
comprising, in combination, an elongated barrel
adapted to be mounted on the drill and having
a -tool socket, an -impact member reciprocable
axially in the barrel in operative relation to the
socket, means forming shoulders adjacent oppo
site ends of said member, a pair of spaced abut
'mentsv in said barrel, a collar loosely mounted on
said~~member and abutting against the shoulder
adjacent one end of the member, a flanged sleeve
slidably mounted on the member and abutting
against the shoulder adjacent the other end of
the member, a spring interposed between said
collar and said sleeve operative to yieldably urge
the collar and the flange of the sleeve against
spring means.
l
'
fl. Apercussive tool comprising, in combina
tion, a casing having 'a tool socket at one end, an
elongated impact member> supported in said cas
ing for reciprocation axially toward and from the
socket, a flanged sleeve slidably mounted on said
member, a cam follower at one end oi the mem
ber engageable with one end of the sleeves a fixed
abutment in said casing, spring means yieldably
urging the flange oi said sleeve against said abut
ment, power actuated cam means operative to re
a central position in the barrel, power driven
means acting on said member to retract the same
from the socket, the shoulder at said one end of
tract the impact member against the force of said
spring and to release the member for movement
toward the socket under the action of said spring,
said follower engaging said sleeve to transfer the
impact oi the member to said sleeve after a pre
determined advance of the member.
5. A hammer attachment for rotary drills and
the like comprising, in combination, an elongated
said member engaging said collar in the retrac
barrel having a tool socket at one end, means at
tion of the member to compress said spring be- = y
the other end of the barrel for mounting it on the
said abutments whereby to hold the member in ~
drill, an impact member reciprocable axially in
tween said collar and said sleeve, said spring act
ing through said collar and said shoulder upon
the release of the member to advance it rapidly
said barrel in operative relation to said socket, a
driving spring interposed between said barrel and
said member operative to yieldably urge the
member toward said socket, a cam follower rigid
toward the socket, said sleeve being engaged by
the shoulder adjacent the other end of said mein
ber for movement therewith at a predetermined
with said impact member, a cam arranged to be
driven by the drill and operative in coaction with
said follower to periodically retract the impact
member from said socket and then release the
member, said spring storing up energy incident to
point in its advance and said spring acting to re
sist such movement of the sleeve and therebl7
bring the member to a cushioned stop.
2. A hammer attachment for rotary drills com
prising, in combination, a barrel adapted to be
suoli retraction for advancing the member rap
mounted on the drill and having a tool socket, an
idly toward said socket upon its release, stop
impact member reciprocable axially in the barrel
means including a sleeve element slidable rela
tive to said impact member and yieldably urged
in operative relation to the socket, a pair of
members slidably mounted on said impact mem
40 away from said socket by said spring, a collar
ber, means limiting the movement of the sliding
members toward the respective ends of the im
pact member, a spring interposed between said
sliding members yieldably urging them toward
their limit positions, abutment means in said
barrel engageable by the sliding members at their
limit positions, power actuated means operable
to intermittently retract the impact member from
the socket and to release the same, one of said
sliding members moving with the impact member
in its retraction through the action of said limit
ing means to compress said spring against the
other sliding member held against movement by
its associated abutment, said spring acting
through said one sliding member and its asso- -
interposed between said sleeve element and said
follower, said collar being positioned for engage
ment by said follower before the follower engages
said cam in the advance of said impact member
whereby the energy of said impact member is
transferred to said spring to cushion the impact
of the member.
6. In a percussive tool, in combination, a casing
having a tool socket at one end, an elongated im
pact member supported in said casing for recipro
cation axially thereof toward and from said
socket, a flanged sleeve slidably mounted on said
member, a rigid element adjacent one end of said
impact member positioned for coaction with one
end of said sleeve, a ñxed abutment in said cas
ing, spring means interposed between said sleeve
and said impact member yieldably urging the
flange of said sleeve against said fixed abutment
and said impact member toward said socket,
power actuated means operative to retract the
impact member against the force of said spring
and to release the member for movement toward
the socket under the action of said spring, said
rigid element acting through said sleeve to trans
65 fer the impact of the member through said sleeve
stop.
to said spring upon a predetermined advance of
3. A percussive tool comprising, in combina
the member whereby to bring the member to a
tion, a casing, an impact member supported for
Cushioned stop.
reciprocation in said casing, a flanged sleeve
7. A percussive, tool comprising, in combina
mounted on said member and seated on said cas
ing, spring means interposed between said mem 70 tion, an elongated barrel having a tool socket
at one end, an impact member supported in said
ber and the ñanged end oi’ said sleeve operative
barrel for reciprocation relative to said socket,
to urge the member outwardly of the casing,
power actuated means for retracting said mem
rotatably driven cam means operative to inter
ber from said socket and for releasing it, a power
mittently retract the member against the pres
sure of said spring means and to suddenly release 75 spring adapted to be stressed in response to the
ciated limiting means when the impact member
is released to advance the impact member rapidly
toward the socket, said other sliding member be
ing carried along by the impact member after a
predetermined advance through the action of its
associated limiting means and acting to com
press said spring against said one sliding member
held stationary by its associated abutment where
by the impact member is brought to a cushioned
2,408,484
7
S
retraction of said impact member and operative
ment relative to _said casing; a _power Spring inter
posed between said members yieldably urging the
movable member` against the casing- and the im
upon release of the member to advance lit t0 en
gage a tool bit in said socket, and a force trans
pact member toward the socket, power actuated
means loperative to intermittently retract the im
mitting member movable with said impact mem
ber during the latter portion of the travel thereof ‘
pact member from the socket and thereby com,
press said .Spring against said movable member
forvengaging said spring and thereby for render
ing said spring operative to absorb the impact
and bring said member to a cushioned stop when
the resistance offered _by the tool bit to such ad
vance is insuñicient to absorb the impact.
8. A percussive tool comprising, in combina
and to release the impact member to theV action
of the compressed spring, and means associated
l0
with said iin-_pact „member engageable with said
movable ,member at'a'predetermined point in the
tion, a casing having a tool socket at one end, an
advance Q_f the impact member to compress’the
impact member reciprocable axially in the casing
Spring-against the impact member and thereby ,
bringfthe latter to a cushioned stop.
in operative relation to said socket, a member
mounted for limited axial movement relative to
said impact member and for limited axial move
ARfrHUR R. .SCHWARZKOPR
Документ
Категория
Без категории
Просмотров
0
Размер файла
698 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа