Note: Descriptions are shown in the official language in which they were submitted.
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AUTO HAMMER
BACKGROUND
Auto hammers are commonly used as portable tools in decoration and
construction fields. Chinese Patent Application No. 200820161342.1 discloses
an
auto hammer which comprises a main body and a muzzle part connected to the
main
body. The muzzle part is generally composed of a hollow cylindrical sleeve in
which
a hole for receiving a magnet is drilled. The magnet is engaged in the hole
for
attaching a nail placed in a striking device to clamp the nail. The
disadvantages of
such auto hammer are that: the magnet is located at the edge of the sleeve, so
that
the nail cannot be positioned at the centre of the sleeve and cannot be
parallel to the
centre line of the sleeve (i.e,. the attached nail is deflected). The magnet
also
cannot clamp other non-magnetic materials, such as wooden tenons and the like.
SUMMARY
Provided is an auto hammer, in which nails or other components can be
securely clamped within a striking device for convenience of the user.
To this end, an auto hammer is provided with convenient operation, better
visibility and compact structure, which comprises a striking device having a
striking
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mechanism. The clamping mechanism includes at least two clamping elements and
a
sleeve, and the clamping elements are movable between a closed position and an
opened position. The sleeve is provided with slots in which the clamping
elements
are movable relative to the sleeve such that the clamping elements are closed
when
located at a first position of the slots and the clamping elements are opened
when
located at a second position of the slots.
The sleeve is provided with slots on at least two sides thereof, and the slots
on each side are symmetric to each other. The clamping elements comprise
driving
portions which are disposed in the slots and movable along the slots.
Preferably, the
sleeve is provided with slots on four sides thereof, and the slots on each
side are
symmetric to each other. The driving portions of the clamping elements are
disposed
in the slots and movable along the slots. Due to the arrangement that the
slots are
configured on four sides of the sleeve, the clamping elements can clamp the
shank of
the nail in a wider range to obtain a better effect of clamping.
Further, the slots are configured as flexural-type to advantageously shorten
the sliding distance of the sleeve, and then the structure of the entirely
device is
more compact.
Further, the driving portions are mounted removably on the clamping
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elements and/or integrated with the clamping elements.
Further, the clamping elements include any one or any combination of jaw,
spring, magnet, screw or chuck for retaining a component.
Further, the clamping elements include recesses, and one component is
retained in the recesses at the closed position, or disengaged from the
recesses at the
opened position.
Further, the striking device includes a striking rod which passes through a
released region formed by the clamping elements at the opened position.
Further, the clamping mechanism includes a bush which passes through the
released region.
Further, the clamping mechanism includes a first biasing device for biasing
the sleeve toward the workpiece.
Further, the clamping mechanism includes a second biasing device for
biasing the clamping mechanism toward the workpiece.
Further, the clamping mechanism includes a third biasing device for biasing
the bush toward the workpiece.
Further, the clamping elements are interlocked to advantageously open or
close the clamping elements simultaneously.
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Further, the sleeve includes a locking mechanism which includes at least one
protrusion and a spanner, the clamping elements are located at the opened
position
after one protrusion and the spanner are interlocked, and the bush is exposed
from
the sleeve after another protrusion and the spanner are interlocked.
Further, the sleeve is provided with a sheath, and a toggle switch engages
with the sheath for moving together therewith. The user may open the clamping
elements by pushing and pressing the sheath or pushing the toggle switch.
Further, the sheath and/or the sleeve are composed of transparent material for
conveniently determining the specific position of the striking rod by the
user.
Further, the sheath and/or the sleeve are provided with recesses thereon for
increasing the visibility of the component.
Further, the striking rod exerts a striking force on the component for moving
it, and a transmission mechanism is arranged for converting rotating movement
of
the motor into linear reciprocating movement of the striking rod.
Further, the striking rod continually strikes the component for inserting it
into
the workpiece gradually.
Further, the transmission mechanism includes an impact wheel having at least
one protrusion, and the protrusion exerts impact motions on the striking rod
in
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cycles.
BRIEF DESCRIPTION OF THE DRAWINGS
The detailed embodiments of the present invention are described below in
conjunction with the accompanied drawings, in which:
FIG. 1 is a perspective view of an auto hammer according to present
invention;
FIG. 2 is a sectional view of the auto hammer of FIG. 1 taken along a
combination surface of the two half housings;
FIG. 3 is a sectional view of the auto hammer of FIG. 1 taken along a
direction perpendicular to the combination surface of the two half housings;
FIG. 4 is a partially exploded view illustrating a transmission mechanism of
the auto hammer of FIG. 1;
FIGS is a cutaway view of the auto hammer of FIG.2 taken along axis A-A;
FIG.6 is a detailed plan view illustrating a clamping mechanism of the auto
hammer of FIG. 1, wherein the clamping elements are located in a closed
position;
FIG.7 is a detailed plan view illustrating a clamping mechanism of the auto
hammer of FIG. 1, wherein the clamping elements are located in an opened
position;
FIG.8 is a cutaway view of the clamping mechanism of FIG.6 taken along
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axis B-B;
FIG.9 is a cutaway view of the clamping mechanism of FIG.7 taken along
axis C-C;
FIG.10 is a schematic view illustrating that the nail is clamped in the
clamping mechanism and the sleeve of the auto hammer exactly contacts the
workpiece, at this moment, the clamping elements are located in the opened
position;
FIG. 11 is a schematic view illustrating that the nail is nailed into the
workpiece, and the protrusions on the sleeve of the auto hammer exactly abuts
against the spanner;
FIG.12 is a schematic view illustrating that the nail is nailed into the
workpiece, and the body of the clamping mechanism of the auto hammer exactly
contacts the workpiece, at this moment, the clamping element are located in an
entirely opened position;
FIG.13 is a schematic view illustrating that the nail is nailed into the
workpiece, and the bush of the clamping mechanism of the auto hammer exactly
contacts the workpiece; and
FIG.14 is a schematic view illustrating that the nail is totally nailed into
the
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workpiece.
DETAILED DESCRIPTION
As shown in FIGS. 1 and 2, an auto hammer 1 of an exemplary embodiment
includes a housing 2 containing a motor M and a striking device 6. The housing
2 is
formed by combining a left half housing 2' with a right half housing 2". A
substantially vertical grip 4 is formed by the main body of the housing 2 and
the
upper portion of the housing 2 has a head assembly 3 which includes a
transmission
mechanism and the striking device 6 formed by protruding forwardly.
In this embodiment, the auto hammer 1 comprises a battery pack (not shown)
for supplying electricity to the motor M. However, the auto hammer according
to the
invention need not be restricted to the use of a DC power supply and may be
equally
powered by a source of AC power. A switch 7 is arranged on the housing 2 for
controlling the motor M to start or stop. The striking device 6 includes a
striking rod
61 mounted therein by a spring. The striking rod 61 is disposed substantially
horizontally and moves in a reciprocating manner within the striking device 6.
During operation, the end surface of the striking end 611 of the striking rod
61 acts
on the components such as fasten pieces like nails, and tenons or objects like
bricks
and so on. The striking device 6 further includes a receiving cavity 63, the
inner
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diameter of which is larger than the diameters of the nails commercially used
or
other components, thus nails or other components with different sizes can be
placed
therein.
As shown in FIGS. 3 and 4, a rotation-linear motion transmission mechanism
is arranged in the housing 2 for converting rotating motions of the motor M
into
impact motions of the striking rod 61. The motor M is mounted vertically in
the
housing 2 with an upward motor shaft X' thereof transmitting the rotation
power to a
rotating shaft 35 by means of a multi-stage gear transmission mechanism
including
bevel gears. The rotating shaft 35 is supported on the upper portion of the
housing
by two bearings at opposite ends. A pair of inclined slots 36, each of which
is "V"
shaped and opens backwardly, is formed on the rotating shaft 35. An impact
wheel
31 is mounted on the rotating shaft 35, which is a generally hollow cylinder
and is
provided with a pair of curved guiding slots 37 which is formed on its inner
cylindrical surface and opposite to the inclined slots 36 respectively. The
opening of
the curve of each guiding slot 37 is orientated opposite to the "V" shaped
inclined
slot 36. The bottom of the inclined slots 36 and the guiding slots 37 are
semicircle.
A pair of steel balls 38 is arranged respectively in the chambers formed by
the
corresponding inclined slots 36 and the guiding slots 37 and can move along
the
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inclined slots 36 and the guiding slots 37. The impact wheel 31 can thus be
driven to
rotate through the steel balls 38 located in the inclined slots 36 when the
rotating
shaft 35 is rotated. A pair of projections 32, which is disposed oppositely
along the
diameter direction of the impact wheel 31, is provided on the outer periphery
of the
impact wheel 31. When the switch 7 is triggered, the motor M is actuated and
drives
the rotating shaft 35 to rotate by the multi-stage gear transmission
mechanism. As
a result, the rotating shaft 35 then drives the impact wheel 31 to rotate
therewith via
the steel balls 38.
As shown in FIG. 4, an energy storing spring 40 is mounted between the
impact wheel 31 and the rotating shaft 35 in such a manner that one end of the
spring
abuts against a shoulder 351 of the rotating shaft 35 and the other end
thereof abuts
against the impact wheel 31. The axial force of this energy storing spring 40
may
cause the impact wheel 31 to locate at a first axial position relative to the
rotating
shaft 35. At this first axial position, the impact wheel 31 rotates
circumferentially
under the action of the rotating shaft 35 and the steel balls 38. If the
impact wheel 31
rotates to a position where the projections 32 may come into contact with the
striking rod 61, the striking rod 61 stops the rotation of the impact wheel 31
temporarily because it encounters a larger resistance which cannot be overcome
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temporarily. As a result, the impact wheel 31 is forced to gradually press the
energy
storing spring 40 and thereby moves from the first axial position to a second
axial
position. At this second axial position, the projections 32 of the impact
wheel 31
depart from the striking rod 61 and then the braking is released. At this
moment, the
energy storing spring 40 starts to release the elastic potential energy
thereof. Under
the function of the rebound force of the energy storing spring 40, the impact
wheel
31 is axially pressed back to its first axial position, and is moved at a
higher speed
than that of the rotating shaft with the cooperation of the inclined slots 36,
the
guiding slots 37 and the steel balls 38. As a result, the stricken end 612 of
the
striking rod 61 is impacted by the projections 32 of the impact wheel 31 to
make the
striking rod 61 moves linearly at high efficiency, and thus a strike action is
achieved.
After the first striking action is completed, when the impact wheel 31 rotates
to be
stopped by the striking rod 61 again, it enters into a second impact cycle,
and the
succeeding impact cycles will be achieved in the same manner.
With reference to FIGS. 2 and 5-9, the striking device 6 further includes a
clamping mechanism 5 therein for clamping the nails or other components. The
clamping mechanism 5 is composed of clamping elements 52a, 52b, 52c and 52d
and
mounted in the body 51 of the clamping mechanism 5. The clamping elements 52a,
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52b, 52c and 52d generally have a first position and a second position. At the
first
position, i.e., a closed position, the clamping elements 52a and 52b are
closed with
respect to each other, and the clamping elements 52c and 52d are also closed
with
respect to each other to create a clamped region in which the nails or other
components may be retained, as shown in FIGS. 6 and 8. At the second position,
i.e.,
a opened position, the clamping elements 52a and 52b are opened with respect
to
each other, and the clamping elements 52c and 52d are also opened with respect
to
each other to create a state in which the nails may be struck continually by
the
striking rod until the nail is completely nailed into the workpiece, as shown
in FIGS.
7 and 9. When the clamping elements are located in the opened position, the
nails or
other components may be placed into the receiving cavity 63 and retained in
the
clamped region upon the clamping elements being closed. Each clamping element
is
provided with a recess which may exactly engage with the arc of the shank of
the
nail. The clamping effect will be enhanced if the contact areas between the
clamping
elements and the shanks of the nails or other components are increased. Also,
the
nails or other components with different sizes can be retained independently
by the
clamping elements since the clamping elements can be adjusted. Once the
clamping
elements are opened, the nails or other components can be disengaged from the
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recesses.
The clamping elements as mentioned above may be any one or any
combination of jaw, spring, magnet, screw or chuck and the like for retaining
elements.
As shown in FIGS. 6-9, a sleeve 8 is configured as a hollow cuboid and
provided with inclined slots. Two symmetrical inclined slots 81 and 82 are
disposed
on each of four sides (i.e., front side, rear side, top side and bottom side)
of the
sleeve. The inclined slots on the front side are shown in FIG. 6, and the
inclined
slots on other three sides are arranged similarly. The inclined slots 81 and
82 may
also be disposed integrally to form a "V" shaped slot. Moreover, the inclined
slots
81 and 82 are not linear-type but flexural-type inclined slots, which is
advantageous
to shorten the stroke of the sleeve 8, and make the structure of the entire
device more
compact. The flexural-type inclined slots depicted herein refer to non-linear-
type
recesses, including curved recesses and recesses formed by two or more lines
with
different slopes and the like. Two driving portions 53a, 53b of the clamping
elements pass through the clamping elements 52a, 52b respectively, and each of
them is mounted at opposite ends into the corresponding inclined slots 81, 82
on the
top and bottom sides of the sleeve 8. The other two driving portions 53c, 53d
pass
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through the clamping elements 52c, 52d respectively, and each of them is
mounted
at opposite ends into the corresponding inclined slots 81, 82 on the front and
rear
sides of the sleeve 8. An interlock structure is formed by the four driving
portions.
When the clamping elements are located in the first position, i.e., the closed
position,
four clamping elements clamp the nail in the manner that the opposite ends of
the
driving portion 53a are respectively positioned at one end of the
corresponding
inclined slots 81 on the top and bottom sides of the sleeve 8, the opposite
ends of the
driving portion 53b are respectively positioned at one end of the
corresponding
inclined slots 82 on the top and bottom sides of the sleeve 8, the opposite
ends of the
driving portion 53c are respectively positioned at one end of the
corresponding
inclined slots 81 on the front and rear sides of the sleeve 8, and the
opposite ends of
the driving portion 53d are respectively positioned at one end of the
corresponding
inclined slots 82 on the front and rear sides of the sleeve 8. The four
driving portions
move together with respect to the respective inclined slots. As shown in FIGS.
7 and
9, when the clamping elements are located in the second position, i.e., the
opened
position, the four clamping elements are opened with respect to each other in
the
manner that the opposite ends of the driving portion 53a are respectively
positioned
at the other end of the corresponding inclined slots 81 on the top and bottom
sides of
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the sleeve 8, and the opposite ends of the other driving portions are
respectively
positioned at the other end of the corresponding inclined slots on two sides
of the
sleeve, whereby the nail may be struck continually by the striking rod 61
passing
through the clamping elements until it is totally nailed into the workpiece.
It could
be understood that the driving portions may be integrated with the clamping
elements.
Upon assembly, each clamping element is firstly placed within the body 51 of
the clamping mechanism, and then each driving portion is passed through the
respective clamping element. A sheath 9, which may prevent the driving
portions
disengaging from the sleeve 8 and dropping out from the auto hammer, is
further
mounted on the outer surface of the sleeve 8. The body 51 is connected to one
end of
a ferrule 10 for moving therewith. It could be understood that, the driving
portions
also may be integrated with the clamping elements.
As shown in FIGS. 10-14, a first biasing device is provided in the form of a
spring 11 for biasing the sleeve 8 toward the left, namely toward the
workpiece to be
processed, so that the clamping elements are located at the closed position.
The
spring 11 is mounted on the sleeve 8 at one end and on the protrusion of the
ferrule
10 at the other end. When the sleeve 8 contacts the workpiece, the user has to
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counteract the pressure exerted by the first biasing device to open the
clamping
elements. A second biasing device is provided in the form of a spring 12 for
biasing
the ferrule 10 toward the left. The spring 12 is mounted on the ferrule 10 at
one end
and on a stop collar 13 at the other end. When the end surface 51a of the body
51
contacts the workpiece, the body 51 will move together with the sleeve 8 by
counteracting the pressure exerted by the second biasing device. A third
biasing
device is provided in the form of a spring 14 for biasing a bush 15 toward the
workpiece. The spring 14 is mounted on the gear box at one end and on the bush
15
at the other end. When the bush 15 contacts the workpiece, the bush 15 will
move
together with the sleeve 8 and the ferrule 10 by counteracting the pressure
exerted
by the third biasing device till the nail is totally nailed into the
wordkpiece.
The springs as mentioned above may be compression springs or coil springs.
The springs may be substituted with other elastic members or biasing members
for
producing attraction force or exclusion force, for example, the springs 11, 12
and 14
may be replaced by magnetic members.
In operation, if the clamping elements are located in the closed position as
shown in FIG. 2, the user may overcome the pressure exerted by the first
biasing
device 11 through a toggle switch 21 to push the sleeve 8 to move in the right
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direction as pictured. The toggle switch 21 is mounted on the housing 2 and
engages
with the sheath 9. If the toggle switch 21 is moved by the user for driving
the sleeve
8 and the sheath 9 to move together in the right direction as pictured, or the
sleeve 8
is pressed directly to move in the right direction as pictured, the clamping
elements
will be totally opened and the user may hear a "click." The nail may now be
placed
in the receiving cavity 63 and then be retained individually by the clamping
elements by releasing the spanner 16. Subsequently, the auto hammer is
positioned
to make the nail adjacent to the workpiece, and the switch 7 maybe pushed when
the
battery pack (not shown) is loaded so as to activate the motor M for driving
the
striking rod 61 to move in a reciprocating manner. The head of the nail will
be
struck repeatedly by the striking rod 61 once the auto hammer is pressed on
the
workpiece by the user, so that the nail is inserted gradually into the
workpiece. If the
user wants to stop the strike before the clamping elements are opened, he may
turn
the toggle switch 21 to again move the sleeve 8, or press the sleeve 8
directly
inwardly, so that the clamping elements are opened and thus the nail may
disengage
from the auto hammer. During the gradually inserting of the nail, as shown in
FIG.
10, the user may overcome the pressure exerted by the spring 11 to open the
clamping element when the sleeve 8 engages with the workpiece, which allows
the
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nail to be inserted partly into the workpiece before being released. As shown
in
FIGS. 11 and 12, the sheath 9 includes at least one protrusion 91 at the lower
end
thereof, and the sheath 9 may push out the protrusions 101 on two sides of the
ferrule 10 from the internal of the housing while the spanner 16 is pushed out
by the
protrusion 91, so that the body 51 may slide inwardly to the housing. Upon the
end
surface 51a of the body 51 contacting the workpiece, as shown in FIG. 12, the
clamping elements are located in the opened position, the pressure exerted by
the
spring 12 is needed to be counteracted by the user to make the nail head
available
through the clamping elements, while the bush 15 and the striking rod 61 may
also
pass through the clamping elements to continually strike the nail. Upon the
bush 15
contacting the workpiece, as shown in FIG. 13, the pressure exerted by the
spring 14
is needed to be counteracted by the user to make the bush 15 flush around the
nail
head so as to prevent the nail head becoming trapped in any gap which may be
formed after the clamping elements are entirely opened. The nail will thus be
struck
continually until it is nailed totally into the workpiece, as shown in FIG.
14.
The clamping mechanism further includes a locking mechanism such that the
sheath 9 may be locked in the opened position of the clamping elements by the
engagement of the protrusion 91 with the spanner 16 after the nail is nailed
totally
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into the workpiece. The second strike will be achieved by repeating the steps
as
described above after placing one nail into the receiving cavity 63, and
pressing the
spanner 16 to clamp the nail in the receiving cavity 63 by the clamping
elements.
The sheath 9 may further include another protrusion at the lower end to lock
the
sheath 9 at another position, at which the bush 15 is exposed from the sleeve
8 to
increase the visibility of the striking rod 61. At this moment, the striking
end 611 of
the striking rod 61 may be used as a knocking portion of the auto hammer,
which
may knock the workpiece to be processed such as tenon, brick and the like with
the
linear reciprocating movement of the striking rod 61 during operation.
Whereby, the
functions of this machine are increased rather than limited to strike the
fastening
elements into the workpiece. According to this embodiment, the sleeve 8 and
the
sheath 9 may be composed of transparent materials, such as transparent
plastic,
which may also enhance the visibility of the striking rod 61. If the specific
position
of the striking rod 61 can be determined, the striking rod 61 may be used as
an auto
hammer by the user to knock the workpiece to be processed. In addition, the
"V"
shaped recesses provided on the sleeve and the sheath can also enhance the
visibility
of the clamped nail in the case that the nail is smaller, so as to facilitate
the
operation.
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In conclusion, the auto hammer described in this invention is not limited to
the embodiments described above and the configurations shown in the drawings.
There are many obvious variations, substitutes and modifications in the shapes
and
locations of the components based on the present invention, and such
variations,
substitutes and modifications shall all fall in the scope sought for
protection in the
present invention.
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