U.S. patent application number 15/305511 was filed with the patent office on 2017-02-09 for quick-connect chuck mechanism for screwdriver bits and the like.
The applicant listed for this patent is Maxtech Consumer Products Limited. Invention is credited to Satnam Singh, Kailash C. Vasudeva.
Application Number | 20170036330 15/305511 |
Document ID | / |
Family ID | 54331532 |
Filed Date | 2017-02-09 |
United States Patent
Application |
20170036330 |
Kind Code |
A1 |
Singh; Satnam ; et
al. |
February 9, 2017 |
QUICK-CONNECT CHUCK MECHANISM FOR SCREWDRIVER BITS AND THE LIKE
Abstract
A bit holder has a shank at a proximal end thereof and a blind
bit-accepting hole at a distal end thereof, shaped to receive a
correspondingly-shaped tool bit. The bit holder has at least one
locking mechanism which includes an angled path defined in the bit
holder, opening into a side of the bit-accepting hole, extending
away from the bit-accepting hole in a proximal direction at an
acute angle A from a central axis. A locking element is slideable
in the path. A sleeve around the shank is biased towards the
bit-accepting hole by a spring, such that a distal end of the
locking element extends slightly into the bit-accepting hole.
Moving the sleeve towards the proximal end of the bit holder
retracts the locking element from the bit-accepting hole, thereby
releasing the bit. A spring-loaded plunger in the blind hole may be
used to eject the bit automatically when the locking mechanism is
released by the sleeve.
Inventors: |
Singh; Satnam; (Kitchener,
CA) ; Vasudeva; Kailash C.; (Waterloo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Maxtech Consumer Products Limited |
Waterloo |
|
CA |
|
|
Family ID: |
54331532 |
Appl. No.: |
15/305511 |
Filed: |
April 22, 2015 |
PCT Filed: |
April 22, 2015 |
PCT NO: |
PCT/CA2015/050334 |
371 Date: |
October 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61982637 |
Apr 22, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B25B 23/0035 20130101;
B23B 2231/46 20130101; B23B 31/1071 20130101; B23B 31/1074
20130101 |
International
Class: |
B25B 23/00 20060101
B25B023/00; B23B 31/107 20060101 B23B031/107 |
Claims
1. A bit holder having a shank at a proximal end thereof and a
blind bit-accepting hole at a distal end thereof, said
bit-accepting hole being shaped to receive a correspondingly-shaped
tool bit, the bit holder having at least one locking mechanism
comprising an angled path defined in said bit holder, opening into
a side of said bit-accepting hole, extending away from said
bit-accepting hole in a proximal direction at an acute angle A from
a central axis of said bit holder, and a locking element slideable
in said path, such that a distal end of said locking element
extends slightly into said bit-accepting hole, said bit holder
further comprising a sleeve mounted around said shank, biased by a
spring to urge said locking element towards said bit-accepting
hole, connected to said locking element such that moving said
sleeve towards the proximal end of said bit holder retracts said
locking element from said bit-accepting hole.
2. A bit holder as in claim 1, wherein said locking element
comprises a pin connected to said sleeve, for a distal end of said
pin to contact a tool bit.
3. A bit holder as in claim 1, wherein said locking element
comprises a pin connected to said sleeve, said pin having a roller
mounted at a distal end thereof to contact a tool bit.
4. A bit holder as in claim 1; wherein said locking element
comprises a ball and wherein said sleeve has a hook portion
extending therefrom to capture said ball.
5. A bit holder as in claim 1, further comprising a second angled
path defined in said bit holder, opening into a side of said
bit-accepting hole, extending away from said bit-accepting hole in
a distal direction at an acute angle A from a central axis of said
bit holder, and comprising a second locking element, whereby said
tool bit is locked against movement in both directions until said
sleeve is moved.
6. A bit holder as in claim 5, comprising more than one said
locking mechanism spaced apart radially.
7. A bit holder as in claim 6, further comprising a spring-loaded
plunger mounted in a proximal end of said blind hole, to eject a
said tool bit when said locking element is released by moving said
sleeve.
8. A bit holder as in claim 7, wherein said bit and said
bit-accepting hole are hexagonal in cross-section.
9. A bit holder as in claim 7, wherein said bit and said
bit-accepting hole are non-circular in cross-section.
10. A bitdriver comprising a bit holder as in claim 9, and having a
handle mounted on said shank.
11. A bit holder having a shank at a proximal end thereof and a
blind bit-accepting hole at a distal end thereof, said
bit-accepting hole being shaped to receive a correspondingly-shaped
tool bit, the bit holder having at least one locking mechanism
comprising an opening defined in said bit holder, opening into a
side of said bit-accepting hole, and a locking element in said
opening, said locking element comprising a rotatable eccentric cam,
spring biased to rotate its largest radius away from said
bit-accepting hole, said bit holder further comprising a sleeve
mounted around said shank, spring-biased against said eccentric cam
to prevent said eccentric cam from rotating its largest radius away
from said bit-accepting hole.
12. A bitdriver comprising a bit holder as in claim 11, and having
a handle mounted on said shank.
13. A bit holder having a shank at a proximal end thereof and a
blind bit-accepting hole at a distal end thereof, said
bit-accepting hole being shaped to receive a correspondingly-shaped
tool bit, the bit holder having at least one locking mechanism
comprising an opening defined in said bit holder, opening into a
side of said bit-accepting hole, and a locking element in said
opening moveable towards said opening to contact a tool bit ins
said bit-accepting hole, said bit holder further comprising a
sleeve around a body portion of said bit holder, overlying said
opening and biased by a spring towards a normal position, said
sleeve having an internal ramp angled to contact said locking
element to urge said locking element towards said tool bit when
said sleeve is in said normal position, and to free said locking
element when said sleeve is moved from said normal position against
the force of said spring.
14. A bitdriver comprising a bit holder as in claim 13, and having
a handle mounted on said shank.
Description
BACKGROUND
[0001] This invention relates to a quick-change tool bit holder
that can secure a tool bit by using a wedging element on its
external profile. This kind of locking in a quick change holder
provides substantially "no play" holding of a tool bit. The wedging
element moves in a guided angular path within the body of the
holder, the path making a self-locking acute angle with the centre
axis of the holder.
[0002] The invention will normally be used for standard hexagonal
bits. However, the invention can be readily adapted for use with
bits having any polygonal cross-section, including square bits for
example, as well as for use with bits having a non-polygonal
cross-section, for example ovaloid bits with two flats and two
arcs, or tri-centric bits with three flats and three arcs. In
general, the invention can be adapted for use with virtually any
non-circular cross-section. Typical quick change tool bit holders
on the market use some kind of a locking device that engages a
circumferential groove per ANSI B 107.4-1982 or an edge notch per
ASME B107.600-2008 (B107.26) on the hex shank of a tool bit,
resulting in restricting axial freedom of the same.
[0003] Because of inherent features of the circumferential groove
in the tool bits, the locking mechanism in each case is of a binary
nature. This means the conditions are either, on or off, grabbed or
released, locked or unlocked, etc. Due to the stack-up of
tolerances in such bit holder devices, coupled with manufacturing
tolerances of tool bits, there is generally excessive axial and
radial play between the tool bits and the tool bit holder.
Tradespersons and do-it-yourselfers accustomed to using solid screw
drivers or driver/drill bits directly chucked into a hand drill
strongly dislike the resulting sloppy functioning of these quick
change holders.
SUMMARY OF THE INVENTION
[0004] The quick change tool bit holder presented here offers quick
interchangeability of tool bits without compromising the feel of a
solid chuck, by providing a substantially no-play hold on the tool
bit. The design is based upon at least one angularly guided locking
element, the path of which makes a self-locking acute angle `A`
with the center axis of the bit holder. This locking element acts
as a wedge against the outer surface of the tool bit, hence locking
the bit against axial and radial freedom.
[0005] Further details of the invention will be described or will
become apparent in the course of the following detailed description
and drawings of embodiments of the invention, presented as examples
only.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side cross-section of a first example of the
invention, using a pin actuated by a spring-loaded sleeve, shown
with a tool bit inserted;
[0007] FIG. 2A is a cross-section corresponding to FIG. 1, but
without the tool bit;
[0008] FIG. 2B is an end view corresponding to FIG. 2A;
[0009] FIG. 3A is a top view at 90 degrees to FIGS. 1 and 2A;
[0010] FIG. 3B is an end view corresponding to FIG. 3A;
[0011] FIG. 4A is a perspective view showing the sleeve and pin of
FIGS. 1 to 3B;
[0012] FIG. 4B is an exploded perspective view corresponding to
FIG. 4A;
[0013] FIG. 5 is a side cross-section of a second example of the
invention, using a pin and a roller actuated by the spring-loaded
sleeve, shown with a tool bit inserted;
[0014] FIG. 6A is a cross-section corresponding to FIG. 5, without
the tool bit;
[0015] FIG. 6B is an end view corresponding to FIG. 6A;
[0016] FIG. 7A is a top view at 90 degrees to FIGS. 5 and 6A;
[0017] FIG. 7B is an end view corresponding to FIG. 7A;
[0018] FIG. 8 is a perspective view showing the sleeve, pin and
roller of FIGS. 5 to 7A;
[0019] FIG. 9 is a side cross-section of a third example of the
invention, very similar to the second example, but with the
bit-holder body in two pieces;
[0020] FIG. 10A is a side cross-section of a fourth example of the
invention, very similar to the previous examples, but using a
ball;
[0021] FIG. 10B is a side cross-section where the mechanism is
identical to that of FIG. 10A, simply illustrating that for all
embodiments the locking does not depend on the bit having a
circumferential groove;
[0022] FIG. 11 is a side cross-section of a fifth example of the
invention, using a ball holder and a ball actuated by a
spring-loaded sleeve, shown with a tool bit inserted;
[0023] FIG. 12A is a cross-section corresponding to FIG. 11,
without the tool bit;
[0024] FIG. 12B is an end view corresponding to FIG. 12A;
[0025] FIG. 13A is atop view at 90 degrees to FIGS. 11 and 12A;
[0026] FIG. 13B is an end view corresponding to FIG. 13A;
[0027] FIG. 14 is a perspective view showing the sleeve, ball
holder and ball of FIGS. 11 to 13A;
[0028] FIG. 15A is a side cross-section of a sixth example of the
invention, where the sleeve is placed in front of the open end of
the body/housing, shown with a tool bit inserted;
[0029] FIG. 15B is an end view corresponding to FIG. 15A;
[0030] FIG. 16A is a side cross-section of a seventh example of the
invention, showing two opposing bit-locking elements one acting in
one direction and the other acting in the opposite direction;
[0031] FIG. 16B is an end view corresponding to FIG. 16A;
[0032] FIG. 16C is a side cross-section of the seventh example,
showing the sleeve moved forwardly from the holder;
[0033] FIG. 16D is a side cross-section of the seventh example,
showing the sleeve moved rearwardly;
[0034] FIG. 17A is a side cross-section of an eighth example of the
invention, using a spring-loaded cam;
[0035] FIG. 17B is a detailed view corresponding to FIG. 17A;
[0036] FIG. 18 is a side cross-section showing a bit being
inserted; FIG. 19 is a side cross-section showing the bit locked in
place;
[0037] FIG. 20 is a side cross-section of a ninth example of the
invention, in which a wedge portion is provided on the inner
diameter of a slideable sleeve;
[0038] FIG. 21 is a corresponding view, showing a bit being
inserted;
[0039] FIG. 22 is a corresponding view, showing the bit locked in
place;
[0040] FIG. 23 is a side cross-section of a tenth example of the
invention, similar to the ninth example, but having a spring-loaded
plunger to eject the tool bit when the locking mechanism is
released;
[0041] FIG. 24 is a corresponding view, showing a bit fully
inserted;
[0042] FIG. 25 is a corresponding view, showing the collar being
pushed forward and the bit being ejected;
[0043] FIG. 26 is a side cross-section of an example of the
mechanism combined with a typical screwdriver handle;
[0044] FIG. 27 is an end view showing three locking mechanisms
offset by 120 degrees from each other;
[0045] FIG. 28 is an end view showing two locking mechanisms offset
by 180 degrees from each other;
[0046] FIG. 29 is an end view showing two locking mechanisms offset
by 120 degrees from each other;
[0047] FIG. 30 is and end view showing an alternative bit and bit
holder cross-section, namely tri-centric; and
[0048] FIG. 31 is and end view showing another alternative bit and
bit holder cross-section, namely ovaloid.
DETAILED DESCRIPTION
[0049] FIGS. 1-4B shows a first example of the invention. The main
body of the bit holder 10 has a shank 11 and a bit-accepting end 12
with a blind bit-accepting hole 13 having a profile to match the
profile of the tool bit 30. The profile will normally be hexagonal,
but as stated above, the invention can be adapted for use with bits
of basically any non-circular cross-section. The shank 11 normally
will be mounted in, for example, a screwdriver handle, as shown in
FIG. 26.
[0050] At least one pin 15, preferably but not necessarily
cylindrical for ease of manufacturing, acts as a locking element.
In the drawings and throughout this description, generally only one
locking element will be described, for convenience. However, to
achieve maximum "no play" performance, there should preferably be
more than one locking element. Preferably, there may be three of
them, offset at 120 degrees from each other.
[0051] The pin 15 preferably has a semi-spherical tip 16, and is
slideable and guided in an angularly formed path 14, the path 14
partially opening into the bit-accepting hole 13 such that the tip
16 extends slightly into the bit-accepting hole 13. As best seen in
FIGS. 4A and 4B, the pin 15 is anchored to a slideable sleeve 20,
by a slot near 17 the end of the pin and a notch 17' in the sleeve.
When the pin connects to the sleeve, the end of the pin sits in the
notch and the outside of the notch sits in the slot so as to anchor
the pin to the sleeve.
[0052] The angle A at which the path 14 is offset from the axis of
the bit holder is preferably in the range of 5 to 13 degrees. Too
large an angle increases the diameter of the mechanism excessively,
and reduces the effectiveness of the locking. Conversely, too small
an angle increase the length of the mechanism, and ultimately also
reduces the effectiveness of the unlocking.
[0053] The sleeve 20 is biased towards the distal end of the
holder, i.e. towards the open end of the bit-accepting hole 13, by
a spring 21 that has its one flat face against the sleeve 20 while
the other face is against a stop ring 22. The stop ring 22 is
retained by lock ring 23 sitting in a recess in the main body 10.
Axial sliding movement of sleeve 20 results in angularly sliding
movement of element 15 within the guided path 14 of the body.
[0054] When a tool bit 30 is axially inserted into the
bit-accepting hole 13, it engages with the tip 16 of the element
15, pushing the element 15 and in turn the sleeve 20 towards the
shank 11. As the insertion of tool bit 30 continues, the element 15
is pushed fully out of the bit-accepting hole 13 and the tip 16 is
in contact with the external surface 31 of the bit 30 until the bit
stops against the terminating end of bit-accepting hole 13. Due to
the spring biasing, the tip 16 of element 15 is continuously pushed
against the outer surface 31 of the tool bit 30, resulting in
wedging and clamping the bit 30 inside the bit-accepting hole 13.
Any effort to pull the tool bit 30 out from the bit-accepting hole
13 only further tightens the grip on the tool bit. This kind of
locking ensures "no play" fitment of the tool bit in the holder. In
order to release the tool bit 30, the sleeve 20 must be pulled back
towards the shank 11 of the body 10, against the force of the
spring 21, thus withdrawing the tip 16 from surface 31 and
therefore freeing the tool bit 30 for removal.
[0055] As shown in FIG. 2A, the angular path makes an acute angle
"A" with the center axis of the bit holder. Preferably, to make the
pressing force between the pin 16 and the bit 30 more effective for
preventing axial movement of the bit 30 in the bit-accepting hole
13, the acute angle "A" is less than 20 degrees, and preferably
less than 15 degrees. In the drawings, a preferred angle of 10
degrees is shown.
[0056] A second example of the invention is shown in FIGS. 5-8. The
mechanism is essentially identical to that of FIGS. 1-4B, except
that the sliding element 15 has a freely rotating roller 18 that
replaces tip 16 of the pin 15. This is most clearly seen in FIG.
8.
[0057] FIG. 9 shows a third example of the invention, which is a
slightly modified version of the first and second examples. In this
example, the angular path for the locking element is formed
partially as a slot in portion 12 of the body 10 and partially into
a coaxial collar 40 press fitted onto the end 12. With this split
construction there is better access to the guide path during
manufacturing, to produce a polished finish with less friction.
[0058] FIGS. 10A and 10B show a fourth example of the invention,
where the bit locking element is a spherical ball 42 positioned at
the distal end of the pin 15 within the angular path 14. The bit
locking function is the same as shown in the earlier examples of
the invention.
[0059] FIG. 10B is identical to FIG. 10A, except that it
illustrates that the invention can be used not only with bits
having a conventional circumferential groove 43 near their proximal
ends (FIG. 10A), but also with bits having no such groove.
[0060] FIGS. 11-14 show a fifth example of the invention, which is
similar to the fourth example (FIGS. 10A and 10B). In this example,
the locking element is a spherical ball 42, but it is anchored to
an extended hook portion 24 of sleeve 20, as best seen in FIG.
14.
[0061] FIGS. 15A and 15B show a sixth example, which is a variation
of the fifth example (FIGS. 11-14). In this sixth example, the
sleeve 20 is placed in front of the open end of the body/housing.
The locking function is the same as in the previous examples, but
in this case, to release the bit, the movement of the sleeve pushes
the ball 42 away from its locking position instead of pulling it
away.
[0062] FIGS. 16A and 16B show a seventh example of the invention,
which is an enhanced version of the sixth example (FIGS. 15A and
15B). In this enhanced version, the bit can be locked in both axial
directions by a dual-biased sliding sleeve 20. One locking element
42 locks the bit against movement in one direction, and the other
locking element 42' locks the bit against movement in the other
direction. The locking elements can be operated for bit release in
one direction at a time. The extended anchoring portions 24 of the
sleeve 20 have an open ended slot and another closed slot anchoring
the locking elements.
[0063] FIG. 16C shows the sleeve 20 pushed forward from the holder.
This forward movement of the sleeve forces the locking element 42'
angularly away from the tool bit and thus frees the bit to be
pushed deeper into the blind hole. FIG. 16D shows sleeve 20 pushed
rearwardly, moving the locking element 42 away from the bit, hence
freeing the bit to be extracted from the holder.
[0064] FIGS. 17A-19 show an eighth and somewhat different example,
where the bit locking element is at least one rotatable eccentric
cam 44. This cam is lightly spring biased in a counter-clockwise
direction by a spring 45. Point `B` is the highest on the
peripheral surface of the eccentric cam while point `C` is the
lowest. A slideable sleeve 20 is strongly biased towards the open
end of bit insertion bit-accepting hole 13, keeping the eccentric
cam 44 pushed in a clockwise direction such that the highest
portion `B` extends into the bit-accepting hole 13. As the tool bit
30 is inserted into the matching bit-accepting hole 13 of the
holder, the eccentric cam 44 is pushed into counter-clockwise
rotation until it rides on the bit surface 31, at the same time
pushing the sleeve 26 back against its bias. Thus the cam 44 acts
as a rotating wedge clamping the tool bit 30 within the
bit-accepting hole 13 of the holder. Any effort to pull out the
tool bit tends to rotate the eccentric cam 44 in a clockwise
direction, resulting in further tightening the grip on the bit. In
order to release the tool bit, the sleeve 26 must be pulled back
against axial spring bias, allowing cam 44 to rotate
counter-clockwise, thus releasing clamping force on the bit for
removal.
[0065] FIGS. 20-22 show a ninth example, in which the wedge portion
50 is provided on the inner diameter of a slideable sleeve 52, the
sleeve being biased towards the shank of the bit holder. The axial
bias of the slideable wedge causes radial movement of a locking
element 42 sitting in a radial hole 54 in the body, the hole
communicating with the bit-accepting recess 13 in the holder body.
The sleeve 52 is pushed against the bias of the spring, towards the
front end of the holder to insert the tool bit into the accepting
bit-accepting hole 13. Once the bit is fully inserted, the sleeve
is released, resulting in locking of the tool bit due to the radial
force of the locking element. To release the bit 30, the sleeve is
pushed forward.
[0066] FIG. 23-25 show a tenth example, similar to the ninth
example (FIGS. 20-22). This tenth example provides automatic
locking of the bit 30 on insertion. In order to release the bit 30,
the sleeve 52 is pushed against the spring bias, resulting in
taking the radial force off the locking element 42, such that the
tool bit is then ejected by a spring-loaded plunger 56. FIG. 24
shows a bit fully inserted, and FIG. 25 shows the collar being
pushed forward and the bit being ejected.
[0067] For clarity and simplicity, most drawings do not show where
the mechanism is installed. However, the usual and typical
application is to mount the mechanism in a screwdriver (bit-driver)
handle. FIG. 26 is a side cross-section showing a mechanism
according to the invention, mounted in a typical
screwdriver/bitdriver handle 100. Obviously any one of the
described examples of the invention can be so mounted.
[0068] It will be evident to those knowledgeable in the field of
the invention that many variations on the examples described above
are conceivable within the scope of the invention. It should
therefore be understood that the claims which define the invention
are not restricted to the specific examples described above.
Possible variations include, for example, the shape of the pin, the
structure of the connectivity and the shape of the tool bit
profile.
[0069] Most of the examples described above show a single locking
mechanism, for clarity of illustration, and for most applications a
single mechanism may suffice. However, it should also be
appreciated that there can be more than one bit-locking mechanism.
For example, FIG. 27 shows three such mechanisms positioned at 120
degrees to each other, to engage three of the faces of a hexagonal
tool bit. Obviously, two opposing mechanisms could also be used, as
shown in FIG. 28. FIG. 29 shows another example, where there are
two mechanisms, offset by 120 degrees. Theoretically there could be
six mechanisms, but clearly that would neither be necessary nor
practical.
[0070] It should also be appreciated that although most of the tool
bits illustrated in the accompanying drawings are shown with a
conventional circumferential groove near the proximal end of the
bit, it is an advantage of this invention that the groove is not
required for locking, unlike most prior art locking mechanisms. The
locking means, whether a pin or a roller or a ball or other,
engages a flat portion of the tool bit, such that no groove is
required. See FIGS. 10B and 16A for specific examples of tool bits
without grooves. However, it should be seen that in the other
drawings, even when the tool bit does have a conventional groove,
that groove is not engaged.
[0071] It should also be appreciated, as stated previously, that
the tool bit does not need to be a conventional hexagonal
cross-section. Other non-circular cross-sections can be used, such
as those shown in FIGS. 30 and 31 (tri-centric and ovaloid
respectively).
[0072] Further variations may be apparent or become apparent to
those knowledgeable in the field of the invention, within the scope
of the invention as defined by the claims which follow.
* * * * *