U.S. patent application number 10/642295 was filed with the patent office on 2005-02-24 for saw blade camping device.
This patent application is currently assigned to Rexon Industrial Corp., Ltd.. Invention is credited to Chen, Ruey-Zon, Ku, George, Lo, Eric.
Application Number | 20050039339 10/642295 |
Document ID | / |
Family ID | 34080752 |
Filed Date | 2005-02-24 |
United States Patent
Application |
20050039339 |
Kind Code |
A1 |
Chen, Ruey-Zon ; et
al. |
February 24, 2005 |
SAW BLADE CAMPING DEVICE
Abstract
A blade clamping device includes a driving shaft and a base
member fixedly mounted to the driving shaft. An opening is defined
in the base member and a blade is inserted in the base member and
connected to the driving shaft. A cam member is pivotably engaged
with the opening of the base member and a cam head contacts a side
of the blade. The base member is received in a casing which is
connected to the electric saw and an opening is defined in the
casing. A lever is pivotably engaged with the opening of the casing
and includes a pushing end which is located beneath a bar of the
cam member so that when pivoting the lever, the pushing end pivots
the cam member to remove the cam head from the blade.
Inventors: |
Chen, Ruey-Zon; (Taichung
Hsien, TW) ; Lo, Eric; (Taichung Hsien, TW) ;
Ku, George; (Taichung Hsien, TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Assignee: |
Rexon Industrial Corp.,
Ltd.
Taichung Hsien
TW
|
Family ID: |
34080752 |
Appl. No.: |
10/642295 |
Filed: |
August 18, 2003 |
Current U.S.
Class: |
30/392 ;
30/338 |
Current CPC
Class: |
Y10T 279/17761 20150115;
Y10T 83/9481 20150401; B23D 51/10 20130101 |
Class at
Publication: |
030/392 ;
030/338 |
International
Class: |
B27B 019/09 |
Claims
1. A blade clamping device comprising: a driving shaft having an
extension extending from a distal end thereof; a base member having
a passage defined therethrough, the driving shaft securely received
in the passage and a blade connected to the driving shaft, a first
opening defined through a side of the base member and communicating
with the passage; a cam member pivotably connected to the base
member and a first end of the cam member being a cam head which is
inserted in the first opening and removably contacting the blade, a
second end of the cam member being a bar, a first torsion spring
connected to the base member to maintain the cam head to contact
the blade; a casing having a second opening defined in a side
thereof and a lever pivotably engaged with the second opening, the
lever including a handle and a pushing end, the pushing end of the
lever located beneath the bar of the cam member, the cam head of
the cam member being pivoted away from the blade by the pushing end
by pivoting the level; and two lugs extend from the base member
with the first opening located therebetween, a tube extending from
one of the two lugs and a slit defined in the tube, the first
torsion spring mounted to the tube and one of two legs of the first
torsion spring engaged with the slit and the other leg pressing on
the bar of the cam member.
2. (Cancelled)
3. The device as claimed in claim 1, wherein the passage includes a
first path and a second path which communicates with the first
path, the driving shaft is securely received in the first path and
the blade is inserted in the second path.
4. The device as claimed in claim 3 further comprising a boss
extending from a side surface of the extension of the blade has a
hole through which the boss extends.
5. The device as claimed in claim 1 further comprising a stop
extending from an edge of the blade and being stopped by an end
surface of the base member.
6. The device as claimed in claim 1, wherein the driving shaft has
two positioning holes and two pins extend through the base member
and are inserted in the two positioning holes.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a saw blade clamping device
for an electric saw. The saw blade can be easily and quickly
fastened or loosened by pulling a lever on the outside of the
barrel of the electric saw.
BACKGROUND OF THE INVENTION
[0002] A conventional saw blade clamping device is disclosed in
U.S. Pat. No. 5,647,133 and FIGS. 1 and 2, wherein the clamping
device includes a body 11 having a slot 111 for receiving a blade
20 therein and a passage 112 defined in communication with the slot
111. A tube 14 has a rod 13 received therein and the rod 13
includes a rectangular end 131 which fits an inner periphery of the
tube 14. A spring 15 is mounted to the rod 13 and biased between
the rectangular end 131 and the inside of the tube 14. The rod 13
is threadedly extends through the body 11 and further has a contact
end 12 which is able to contact a side of the blade 20. The body 11
includes a serrated surface 113 and the tube 14 is firmly urged by
the spring 15 to contact the serrated surface 113. A user has to
pull the tube 14 to remove the tube 14 away from the serrated
surface 113 and then rotate the tube 14 so as to move the rod 13 to
urge the blade 20 or disengage from the blade 20. The user has to
use a force that overcomes the force of the spring 15 and
simultaneously, rotate the tube 14. This is in convenient for the
user to operate the tube 14 in two different directions.
Furthermore, it is difficult to estimate the force that the contact
end 12 contacting the blade 20.
[0003] FIGS. 3 and 4 shows the disclosures in U.S. Pat. No.
6,023,848 which discloses a blade clamping device including a
casing 31 and a base member 32 located in the casing 31. A first
end of a biasing member 33 is connected to the base member 32. A
blade 40 is engaged with the base member 32 and the biasing member
33 includes a protrusion portion 331 which urges against the blade
40. A lever 34 is pivotably connected to the casing 31 and includes
an end that may pushes a free second end of the biasing member 33
to remove the protrusion portion 331 away from the blade 40.
Although the biasing member 33 is easily to operate by operating
the lever 34, the biasing member 33 quickly looses its biasing
force after frequent operation by the lever 34.
[0004] The present invention intends to provide a blade clamping
device that employs a cam member to firmly position the blade and a
lever conveniently pivot the cam member to release the clamp of the
blade.
SUMMARY OF THE INVENTION
[0005] In accordance with one aspect of the present invention,
there is provided a blade clamping device for an electric saw which
comprises a driving shaft having an extension extending from a
distal end thereof and the driving shaft is inserted in a passage
in a base member. A blade is connected to the driving shaft. An
opening is defined through a side of the base member and
communicates with the passage. A cam member is pivotably engaged
with the opening in the base member and a cam member of the cam
member removably contacts the blade. A second end of the cam member
is a bar. A first torsion spring is connected to the base member to
maintain the cam head to contact the blade.
[0006] A casing is mounted to the base member and has an opening
with which a lever is pivotably engaged. The lever includes a
handle and a pushing end which is located beneath the bar of the
cam member. The cam head of the cam member is pivoted away from the
blade by the pushing end by pivoting the lever.
[0007] The present invention will become more obvious from the
following description when taken in connection with the
accompanying drawings which show, for purposes of illustration
only, a preferred embodiment in accordance with the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view to show a first conventional
blade clamping device;
[0009] FIG. 2 is a cross sectional view to show the first
conventional blade clamping device;
[0010] FIG. 3 shows a cross sectional view of a second conventional
blade clamping device;
[0011] FIG. 4 shows that the biasing member is pushed by the lever
to release the clamp of the blade of the second conventional blade
clamping device;
[0012] FIG. 5 is a perspective view to show an electric saw with
the blade clamping device of the present invention;
[0013] FIG. 6 is an exploded view to show the blade clamping device
of the present invention;
[0014] FIG. 7 is a top view to show the torsion spring that
maintains the cam member to contact the blade;
[0015] FIG. 8 shows the positions of the cam member and the lever
which is not yet pivoted, and
[0016] FIG. 9 shows the lever is pivoted to remove the cam head of
the cam member to release the blade.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0017] Referring to FIGS. 5 to 8, the blade clamping device for an
electric saw 50 of the present invention comprises a driving shaft
52 that extends from a distal end of a barrel 51 of the electric
saw 50 and an extension 521 extends from a distal end of the
driving shaft 52. A boss 523 extends from a side surface 522 of the
extension 521 and two positioning holes 520 are defined through the
driving shaft 52.
[0018] A base member 55 has a passage 551 defined therethrough and
the passage 551 includes a first path 5511 and a second path 5512
which communicates with the first path 5511. The driving shaft 52
is securely received in the first path 5511 by extending two pins
552 through the base member 55 and inserted in the two positioning
holes 520. A blade 60 is inserted in the second path 5512 and
includes a hole 61 through which the boss 523 extends. A stop 62
extends from an edge of the blade 60 and is stopped by an end
surface of the base member 55. A first opening is defined through a
side of the base member 55 and communicates with the second path
5512 of the passage 551. Two lugs 553 extend from the base member
55 with the first opening located therebetween. A tube 555 extends
from one of the two lugs 553 and a slit 5551 is defined in the tube
555.
[0019] A cam member 554 is pivotably connected between the two lugs
553 of the base member 55 by a pin 56 and a first end of the cam
member 554 is a cam head which is inserted in the first opening and
removably contacts the blade 60. A second end of the cam member 554
is a bar 5542. A first torsion spring 556 is mounted to the tube
555 and one of two legs of the first torsion spring 556 is engaged
with the slit 5551 and the other leg is inserted in a hole 5543 in
the bar 5542 and presses the bar 5542 of the cam member 554. The
first torsion spring 556 maintains the cam head to normally contact
the blade 60.
[0020] A casing 53 is connected to the distal end of the barrel 51
of the electric saw 50 and has a second opening 532 defined in a
side thereof. A lever 54 is pivotably engaged with the second
opening 532 by a pin 544 extending through a plate 543 on an inside
of the lever 54 and engaged with the opposite walls of the second
opening 532. The lever 54 includes a handle 541 and a pushing end
542 which is located beneath the bar 5542 of the cam member 554. A
second torsion spring 545 is mounted to the pin 544 and one of two
legs of the second torsion spring 545 is hooked at an inside of the
second opening 532 and the other leg is inserted in a hole in the
plate 543.
[0021] As shown in FIG. 9, when releasing the blade 60, the user
simply pulls the handle 541 of the lever 54 to let the pushing end
542 goes counter clockwise to push the bar 5542 of the cam member
554. The cam head of the cam member 554 is then pivoted away from
the blade 60 so that the blade 60 can be removed from the second
path 5512 of the passage 551 and a new blade can be installed. When
releasing the handle 541, the second torsion spring 545 makes the
pushing end 542 pivot clockwise and the first torsion spring 556
pivots the cam head of the cam member 554 to position the blade
again.
[0022] This clamping device improves the shortcomings of the
conventional blade clamping devices and allows the user to quickly
and conveniently replace new blades. Besides, the force that the
clamping member 554 applies to the blade 60 can be controlled in a
pre-determined range.
[0023] While we have shown and described the embodiment in
accordance with the present invention, it should be clear to those
skilled in the art that further embodiments may be made without
departing from the scope of the present invention.
* * * * *