Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
201301-4CA
IMPACT DRIVER SCREW DRIVING DEVICE WITH DEPTH ADJUSTMENT
FIELD OF THE INVENTION
[0001] The present invention relates to a screw driving device and, in
particular,
an impact driver screw driving device with depth adjustment to adjustably
control
a depth to which a screw is driven into a work piece.
BACKGROUND OF THE INVENTION
[0002] Existing devices for driving screws using an impact driver are known,
as
characterized by Applicant's co-pending published United States Patent
application number US/2018/0126523A1, published on 05-10-2018 entitled
Screw Driving Device for Use With An Impact Driver. That device works
extremely
well for consistently driving screws to a predetermined depth determined by a
length of a replaceable nose cone on the device.
[0003] However, it is well known that a device with adjustable screw depth
control
is desirable. It is also understood that the concussive force generated by
impact
drivers transmits to prior art depth adjusting mechanisms, causing those
mechanisms to change depth settings as a screw is driven into a workpiece,
which is most undesirable.
[0004] It is therefore an object of the invention to provide a screw driving
device
for an impact driver with a screw depth adjustment mechanism that will not
change a depth setting to which it has been adjusted while screws are driven
by
the impact driver.
SUMMARY OF THE INVENTION
[0005] The invention therefore provides an impact driver screw driving device
with depth adjustment, comprising: a screw driving mechanism that retains a
screw bit for driving screws into a work surface; a floating sleeve that
surrounds
the screw driving mechanism; a floating sleeve spring that provides a constant
bias between an upper end of the floating sleeve and an upper end of a hollow
clutch sleeve of the screw driving mechanism; a depth adjustment sleeve
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threadedly connected to a bottom end of the floating sleeve, the depth
adjustment
sleeve having
a bottom end with a passage through which the screw bit extends; and a clutch
spring that constantly urges the screw driving mechanism to a drive position.
[0006] The invention further provides an impact driver screw driving device
with
depth adjustment, comprising: a screw driving mechanism that retains a screw
bit for driving screws into a work surface, the screw driving mechanism
comprising a drive shaft with a socket end received in a hollow clutch sleeve;
a
floating sleeve that surrounds the screw driving mechanism; a floating sleeve
spring that provides a constant bias between an upper end of the floating
sleeve
and an upper end of the hollow clutch sleeve; a depth adjustment sleeve
threadedly connected to a bottom end of the floating sleeve, the depth
adjustment
sleeve having a bottom end with a passage through which the screw bit extends;
and a clutch spring captured between a clutch spring retainer clip received in
a
clutch spring retainer clip groove on the drive shaft and a top of the hollow
clutch
sleeve, the clutch spring constantly urging the screw driving mechanism to a
drive
position.
[0007]The invention yet further provides an impact driver screw driving device
with depth adjustment, comprising: a screw driving mechanism that retains a
screw bit for driving screws into a work surface, the screw driving mechanism
comprising a drive shaft with a socket end received in a hollow clutch sleeve,
the
socket end of the drive shaft receiving and retaining the screw bit; a
floating
sleeve that surrounds the screw driving mechanism; a floating sleeve spring
that
provides a constant bias between an upper end of the floating sleeve and an
upper end of the hollow clutch sleeve, the floating sleeve spring being
retained in
a top of the floating sleeve by a spring retainer washer and a washer retainer
clip
received in a retainer clip groove in the upper end of the floating sleeve; a
depth
adjustment sleeve threadedly connected to a bottom end of the floating sleeve,
the depth adjustment sleeve having a bottom end with a passage through which
the screw bit extends; and a clutch spring captured between a clutch spring
retainer clip received in a clutch spring retainer clip groove on the drive
shaft and
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a top of the hollow clutch sleeve, the clutch spring constantly urging the
screw
driving mechanism to a drive position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Having thus generally described the nature of the invention, reference
will
now be made to the accompanying drawings, in which:
[0009] FIG. 1 is a side elevational view of an impact driver screw driving
device
with a depth adjustment mechanism in accordance with the invention;
[0010] FIG. 2 is a cross-sectional view of the depth adjustment mechanism of
the
impact driver screw driving device taken along lines 2-2 of FIG. 1;
[0011 ] FIG. 3 is a side elevational view of the impact driver screw driving
device
showing a depth adjustment sleeve partially cut away to illustrate depth
adjustment notches on a floating sleeve of the depth adjustment mechanism;
[0012] FIG. 4 is a cross-sectional view taken along lines 2-2 of FIG. 1 with
the
impact driver screw driving device in a screw driving position;
[0013] FIG. 5 is a cross-sectional view taken along lines 2-2 of FIG. 1 with
the
impact driver screw driving device in a clutch released position;
[0014] FIG. 6 is a cross-sectional view taken along lines 2-2 of FIG. 1 of the
impact driver screw driving device in a bit-extended position used to extract
a
driven screw.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] The invention provides an impact driver screw driving device with depth
adjustment which has a floating sleeve that surrounds a screw driving
mechanism
that retains a screw bit. A floating sleeve spring provides a constant bias
between
a top of the floating sleeve and a top of the screw driving device. A depth
adjustment sleeve is threadedly connected to a lower end of the floating
sleeve.
The floating sleeve and the depth adjustment sleeve are free to rotate
independently of the screw driving device so concussive force of the impact
driver
does not change a driven screw depth adjustment setting. The driven screw
depth
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adjustment setting is set by manually rotating the depth adjustment sleeve to
one
of a plurality of predetermined driven screw depth settings while gripping the
floating sleeve to prevent rotation thereof.
[0016] FIG. 1 is a side elevational view of an impact driver screw driving
device
with a depth adjustment mechanism 11 in accordance with the invention. The
screw driving device 10 has a drive shaft 12 with a drive end 14 adapted to be
engaged and driven by a portable electric impact driver (not shown), a hand
tool
that is well known in the art. A floating sleeve 16 surrounds the drive shaft
12 of
a screw driving mechanism, which will be explained below with reference to
FIGs.
4-6. A depth adjustment sleeve 18 is threadedly connected to a bottom end of
the
floating sleeve 16, as will be also explained below in more detail with
reference
to FIGs. 2 and 3. The depth adjustment sleeve 18 has a depth adjustment
indicator 20 that indicates a current depth to which a screw is to be driven
by the
screw driving device 10. The depth adjustment indicator 20 aligns with one of
a
plurality of driven screw depth adjustment indexes 22 on the floating sleeve
16,
as will be explained below with reference to FIG. 3. A plurality of depth
adjustment
lock tabs 24 lock the depth adjustment sleeve 18 at a current driven screw
depth
adjustment index 22. To change the driven screw depth adjustment, the depth
adjustment sleeve 18 is manually rotated to a different depth adjustment index
22 by an operator of the impact driver screw driving device 10, which changes
a
depth to which a screw (not shown) is driven in a work piece (not shown) by a
screw bit 26.
[0017] FIG. 2 is a cross-sectional view of the depth adjustment mechanism 11
of
the impact driver screw driving device 10, taken along lines 2-2 of FIG. 1. A
floating sleeve spring 28 provides a constant bias between an upper end of the
floating sleeve 16 and an upper end of the screw driving mechanism 30 (see
FIG.
4). A top of the floating sleeve spring 28 is retained by a spring retainer
washer
32. This permits the floating sleeve 16 and the depth adjustment sleeve 18 to
rotate freely with respect to the screw driving mechanism 30, so concussive
force
of the impact driver does not change the driven screw depth adjustment. The
spring retainer washer 32 is retained within the floating sleeve 16 by a
washer
retainer clip 34 received in a retainer clip groove 35 in a top end of the
floating
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sleeve 16. As can be seen, the depth adjustment sleeve 18 is rotatably secured
on the lower end of the floating sleeve 16 by a male thread 40 on the lower
end
of the floating sleeve 16 that engages a female thread 42 within the depth
adjustment sleeve 18.
[0018] FIG. 3 is a side elevational view of the impact driver screw driving
device
showing the depth adjustment sleeve 18 partially cut away to illustrate depth
adjustment notches 36 on a floating sleeve 16 of the depth adjustment
mechanism 11. The depth adjustment notches 36 are interleaved by depth
adjustment ridges 38. The depth adjustment notches 36 are equally distributed
around a perimeter of the floating sleeve 16, there being one depth adjustment
notch 36 for each depth adjustment index 22 of the screw driving device 10. As
explained above, the depth adjustment sleeve 18 is threadedly connected to the
floating sleeve 16. In one embodiment, the male thread 40 and female thread 42
are arranged such that the depth adjustment mechanism 11 is at maximum depth
setting when the complimentary male thread 40 and female thread 42 are fully
engaged. To change a driven screw depth setting, the operator grips the
floating
sleeve 16 and the depth adjustment sleeve 18 and rotates the depth adjustment
sleeve 18 in an appropriate direction with respect to the floating sleeve 16,
forcing
the depth adjustment lock tabs 24 over the respective depth adjustment ridges
38 until the depth adjustment indicator 20 points to a desired depth
adjustment
index 22. In one embodiment, depth adjustment sleeve slots 44 are provided to
facilitate deflection of the depth adjustment lock tabs 24 as they are
respectively
forced over the respective depth adjustment ridges 38 during a change to a
different depth adjustment index 22.
[0019] FIG. 4 is a cross-sectional view taken along lines 2-2 of FIG. 1 with
the
screw driving mechanism 30 of the impact driver screw driving device 10 in a
screw driving position. In the screw driving position, the screw bit 26
rotates with
the drive shaft 12 and is released from driving engagement with the drive
shaft
12 when the screw driving mechanism 30 is in a clutched position, as will be
explained below with reference to FIG. 5. The drive end 14 of the drive shaft
12
extends through a central passage 48 in a hollow clutch sleeve 46. A top of
the
central passage 48 extends inwardly to form a hollow clutch sleeve stop 50
sized
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to permit the drive end 14 of the drive shaft 12 to pass through, but not
permit a
socket end 52 of the drive shaft 12 to pass through. A plurality of radial
bores 54
through the socket end 52 of the drive shaft 12 respectively house a clutch
bearing 56. The clutch bearings 56 are described in detail in Applicant's
above-
referenced published co-pending United States patent application number
U5/2018/0126523A1, published on May 10. 2018. In one embodiment there are
3 radial bores 54 spaced 120 apart on a radial plane. A flat inner end of the
respective clutch bearings 56 engage flats on the hexagonal screw bit 26 in
the
drive position of the screw driving mechanism 30, so that the screw bit 26
rotates
with the screw driving mechanism 30. The respective clutch bearings 56
collectively disengage from the screw bit 26 when the screw driving device 10
is
in the clutched position, so that the screw bit 26 no longer rotates with the
drive
shaft 12. A clutch spring 58 is captured between a clutch spring retainer clip
60,
held in a clutch spring retainer clip groove 61 on the drive shaft 12, and a
top end
of the hollow clutch sleeve 46. The clutch spring 58 constantly urges the
hollow
clutch sleeve 46 to the drive position of the screw driving device 10. A
doughnut-
shaped magnet 62 is received in a magnet socket 64 in the lower end of the
depth
adjustment sleeve 18. The magnet 62 magnetically attracts a steel screw (not
shown) placed on the screw bit 26 so that the screw remains on the screw bit
26
until the screw is driven by the impact driver screw driving device 10.
[0020]The socket end 52 of the drive shaft 12 has a screw bit socket 66 which
receives and retains the screw bit 26. As explained above, the screw bit
socket
66 is pierced by the plurality of radial bores 54 (only one is shown in the
cross-
section). The radial bores 54 respectively receive a one of the clutch
bearings 56
that respectively engage the flats on the hexagonal screw bit 26 when the
screw
driving mechanism 30 is in the drive position shown. The hollow clutch sleeve
46
has a hollow clutch sleeve groove 68 sized to receive a rounded outer end of
the
respective clutch bearings 56 when the screw driving mechanism 30 is in the
clutched position, so that the clutch bearings 56 disengage the screw bit 26
but
remain captured in the respective radial bores 54. A ball bearing 70 friction
fit in
an axial bore 72 in an upper end of the screw bit socket 66 supports a top end
of
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the screw bit 26 to permit the screw bit 26 to remain stationary while the
drive
shaft 12 rotates freely when the screw driving device 10 is in the clutched
position.
A circlip 73 captured in a radial groove 74 in the end of the screw bit socket
66
engages notches 76 in the screw bit 26 to removably retain the screw bit 26 in
the screw bit socket 66.
[0021] FIG. 5 is a cross-sectional view of the screw driving device 10 shown
in
the clutched position in which the screw bit 26 is released from driving
engagement with the respective clutch bearings 56 so that a screw 78 is no
longer
driven by the screw driving mechanism 30. As the screw is driven into a work
surface 80, the bottom end of the depth adjustment sleeve 18 contacts the work
surface 80 and the drive shaft 12 slides downward through the central passage
48 of the hollow clutch sleeve 46 as the screw 78 is driven into the work
surface
80 until the respective radial bores 54 align with the clutch sleeve groove 68
in
the hollow clutch sleeve 46 and the respective clutch bearings 56 are forced
outwardly into the clutch sleeve groove 68 by pressure exerted by the screw
bit
26 as it engages the driven screw 78. Once the respective clutch bearings 56
enter the hollow clutch sleeve groove 68, they are no longer in contact with
the
respective flats on the screw bit 26 and the screw driving mechanism 30 is in
the
clutched position. Thus, even though the drive shaft 12 may continue to be
rotated
by the impact driver, the screw bit 26 remains stationary and the screw 78 is
no
longer driven. The depth to which the screw is driven into the work surface 80
is
thereby controlled by the depth adjustment index 22 selected by an operator.
When downward pressure on the drive shaft 12 is released by the operator of
the
impact driver, and the screw driving device 10 is moved away from the work
surface 80, the clutch spring 58 urges the drive shaft 12 upwardly and the
screw
driving device 10 returns to the drive position shown in FIG. 4. As the screw
driving device 10 returns to the drive position, an inclined bottom surface 82
of
the clutch sleeve groove 68 forces the respective clutch bearings 56 back into
contact with respective flats of the screw bit 26.
[0022] FIG. 6 is a cross-sectional view of the screw driving device 10 shown
in
FIG. 4 manually held in a reverse drive position typically used to extract a
driven
screw from a workpiece. In order to place the screw driving device 10 in the
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reverse drive position, the floating sleeve 16 is gripped by the operator and
pulled
upwardly against the bias of the clutch spring 58. In the reverse drive
position,
the respective clutch bearings 56 are below the clutch sleeve groove 68 in the
hollow clutch sleeve 46 and engage respective flats on the screw bit 26, so
that
rotation of the drive shaft 12 in either direction rotates the screw bit in
the same
direction. This permits a driven screw 78 to be extracted from the work
surface
80. Because the depth adjustment mechanism 11 rotates independently of the
screw driving mechanism 30, the operator can hold the impact driver screw
driving device 10 in the reverse drive position while extracting a screw for
as long
as necessary. This more can also be used to drive a screw deeper into the work
surface 80, if desired.
[0023] The embodiments of the invention described above are intended to be
exemplary only. The scope of the invention is therefore intended to be limited
solely by the claims.
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