U.S. patent application number 15/978186 was filed with the patent office on 2019-11-14 for up-and-down motion mechanism for belt sander.
The applicant listed for this patent is Chin-Chin Chang. Invention is credited to Chin-Chin Chang.
Application Number | 20190344397 15/978186 |
Document ID | / |
Family ID | 68463893 |
Filed Date | 2019-11-14 |
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United States Patent
Application |
20190344397 |
Kind Code |
A1 |
Chang; Chin-Chin |
November 14, 2019 |
UP-AND-DOWN MOTION MECHANISM FOR BELT SANDER
Abstract
An up-and-down motion mechanism for a belt sander including a
continuous loop of sandpaper mounted on two end drums, includes a
worktable including an opening with the belt sander moveably
disposed therethrough, two bifurcations on an underside, and a
housing mounted to the underside; a base releasably secured to the
worktable; an electric motor in the housing and configured to
repetitively move up-and-down relative to the worktable, the motor
including an upper motor shaft rotatably connected to one drum, a
lower worm screw, and two legs; and a transmitting assembly
disposed in the housing and including a rotational shaft rotatably
disposed through the legs, a worm wheel with the rotational shaft
disposed through and meshing with the worm screw, two cams secured
to two ends of the rotational shaft respectively, and two links
each having one end connected to one arm and the other end
connected to one bifurcation.
Inventors: |
Chang; Chin-Chin; (Taichung
City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chang; Chin-Chin |
Taichung City |
|
TW |
|
|
Family ID: |
68463893 |
Appl. No.: |
15/978186 |
Filed: |
May 13, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24B 21/22 20130101;
B24B 47/04 20130101 |
International
Class: |
B24B 21/22 20060101
B24B021/22; B24B 47/04 20060101 B24B047/04 |
Claims
1. An up-and-down motion mechanism for a belt sander including a
continuous loop of sandpaper mounted on two end drums, comprising:
a detachable worktable including an opening with the belt sander
up-and-down moveably disposed therethrough, two bifurcations on an
underside, a housing mounted to the underside, a chute disposed
under both one drum and the opening, and two cylindrical columns
extending downward from the underside of the worktable; a base
including a plurality of posts releasably secured to the underside
of the worktable; a control device mounted to the base; an electric
motor disposed in the housing and including an upper motor shaft
rotatably connected to one drum, a lower worm screw, two legs, at
least one first hollow cylindrical member slidably put on one
cylindrical column, and at least one second hollow cylindrical
member slidably put on the other cylindrical column; and a
transmitting assembly disposed in the housing and including a
rotational shaft rotatably disposed through the legs, a worm wheel
with the rotational shaft disposed through and meshing with the
worm screw, two cams secured to two ends of the rotational shaft
respectively, two links with the electric motor disposed
therebetween, each link having one end connected to one arm and the
other end connected to one bifurcation, and a biasing member having
one end anchored at a bottom of the electric motor and the other
anchored at the underside of the worktable.
2. The up-and-down motion mechanism of claim 1, wherein in response
to activating the electric motor, the worm screw rotates to rotate
the worm wheel which in turn rotates the cams, the rotary motion of
the worm wheel is transformed into linear motion of the links, and
the electric motor repetitively moves up-and-down, thereby
repetitively moving the belt sander up-and-down.
3. The up-and-down motion mechanism of claim 1, wherein the number
of the post is four.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The invention relates to belt sanders and more particularly
to an up-and-down motion mechanism for a belt sander, the
up-and-down motion mechanism including an electric motor, two cams
and a worm drive, so that a belt sander disposed above the motor
may repetitively move up or down as the motor activates.
2. Description of Related Art
[0002] A conventional motion mechanism for a belt sander including
a continuous loop of sandpaper mounted on two end drums and
comprises an electric motor, a pivotal member, a link, and a
reduction gear assembly. After activating the electric motor, the
drums may move laterally due to operative cooperation of the motor
shaft, the pivotal member, the link and the reduction gear
assembly. As a result, the continuous loop of sandpaper may move
laterally.
[0003] However, the conventional motion mechanism for a belt sander
is disadvantageous because the movement of the belt sander is not
smooth, its operation is not reliable, and the mechanism is
complicated.
[0004] Thus, the need for improvement still exists.
SUMMARY OF THE INVENTION
[0005] It is therefore one object of the invention to provide an
up-and-down motion mechanism for a belt sander including a
continuous loop of sandpaper mounted on two end drums, comprising a
detachable worktable including an opening with the belt sander
up-and-down moveably disposed therethrough, two bifurcations on an
underside, a housing mounted to the underside, a chute disposed
under both one drum and the opening, and two cylindrical columns
extending downward from the underside of the worktable;a base
including a plurality of posts releasably secured to the underside
of the worktable; a control device mounted to the base; an electric
motor disposed in the housing and including an upper motor shaft
rotatably connected to one drum, a lower worm screw, two legs, at
least one first hollow cylindrical member slidably put on one
cylindrical column, and at least one second hollow cylindrical
member slidably put on the other cylindrical column; and a
transmitting assembly disposed in the housing and including a
rotational shaft rotatably disposed through the legs, a worm wheel
with the rotational shaft disposed through and meshing with the
worm screw, two cams secured to two ends of the rotational shaft
respectively, two links with the electric motor disposed
therebetween, each link having one end connected to one arm and the
other end connected to one bifurcation, and a biasing member having
one end anchored at a bottom of the electric motor and the other
anchored at the underside of the worktable.
[0006] The above and other objects, features and advantages of the
invention will become apparent from the following detailed
description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of a belt sander incorporating
an up-and-down motion mechanism according to the invention;
[0008] FIG. 2 is an exploded perspective view of FIG. 1;
[0009] FIG. 3 is an exploded perspective view of the components
shown in top right corner of FIG. 2;
[0010] FIG. 4 is a perspective view of the motor mounted on the
underside of the worktable, and the transmitting assembly mounted
to the motor;
[0011] FIG. 5 is an exploded view of FIG. 4;
[0012] FIG. 6 is a perspective view of the motor and the
transmitting assembly;
[0013] FIG. 7 is a view similar to FIG. 6 showing the meshing of
the worm screw and the worm wheel and their rotations in
operation;
[0014] FIG. 8 is an exploded perspective view of FIG. 7;
[0015] FIG. 9 is a side elevation schematically showing a downward
motion of both the motor and the belt sander; and
[0016] FIG. 10 is a view similar to FIG. 9 showing an upward motion
of both the motor and the belt sander.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIGS. 1 to 10, an up-and-down motion mechanism
for a belt sander 1 in accordance with the invention is shown. The
belt sander 1 includes a continuous loop of sandpaper 11 mounted on
two end drums 12. The up-and-down motion mechanism includes the
following components as discussed in detail below.
[0018] A detachable worktable 2 includes an opening 21 with the
belt sander 1 up-and-down moveably disposed therethrough, two
bifurcations 22 on the underside, a housing 23 mounted to the
underside with a portion of the opening 21 disposed thereabove, a
chute 24 disposed under both one drum 12 and the opening 21, and
two cylindrical columns 25 extending downward from the underside of
the worktable 2.
[0019] A base 3 includes four posts 31 releasably secured to the
underside of the worktable 2. A control device 4 mounted to the
base 3.
[0020] An electric motor 5 is disposed in the housing 23 and
includes an upper motor shaft 51 rotatably connected to one drum 12
via an adapter 54, a lower worm screw 52, two legs 53, and three
hollow cylindrical members 55 in which one hollow cylindrical
member 55 is slidably put on one column 25 and the other two hollow
cylindrical members 55, aligned vertically, are slidably put on the
other column 25. Both the motor shaft 51 and the worm screw 52
rotate at the speed as the motor 5 activates.
[0021] A transmitting assembly 6 is disposed in the housing 23 and
includes a rotational shaft 61 rotatably disposed through the legs
53, a worm wheel 62 with the rotational shaft 61 disposed through
and meshing with the worm screw 52 to transfer motion in 90-degree,
two cams 63 secured to two ends of the rotational shaft 61
respectively, two links 64 with the motor 5 disposed therebetween,
each link 64 having one end connected to one arm 63 and the other
end connected to one bifurcation 22, and a torsion spring 65 having
one end anchored at a bottom of the motor 5 and the other anchored
at the underside of the worktable 2.
[0022] In response to activating the motor 5, the motor shaft 51
rotates and in turn, one drum 12 rotates. Thus, the continuous loop
of sandpaper 11 shapes and finishes, for example wood. Generated
sawdust is discharged to a collector (not shown) through the chute
24. The subject of the invention is discussed below.
[0023] The worm screw 52 rotates to rotate the worm wheel 62 which
in turn rotates the cams 63. Further, the rotary motion of the worm
wheel 62 is transformed into linear motion (i.e., repetitive
up-and-down motion) of the links 64 due to the provision of the
cams 63. Furthermore, the motor 5 is capable of repetitively moving
up-and-down because the cylindrical members 55 are slidably put on
the columns 25. As a result, the belt sander 1 repetitively moves
up-and-down. This has the advantages of balancing the load of the
continuous loop of sandpaper 11 and prolonging the useful life of
the continuous loop of sandpaper 11. It is noted that the provision
of the torsion spring 65 can assist in the returning of the motor 5
to its original position after being lowered or lifted.
[0024] While the invention has been described in terms of preferred
embodiments, those skilled in the art will recognize that the
invention can be practiced with modifications within the spirit and
scope of the appended claims.
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