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US-12617056-B2 - Belt sander capable of automatically adjusting oscillating position of abrasive belt

US12617056B2US 12617056 B2US12617056 B2US 12617056B2US-12617056-B2

Abstract

A belt sander includes a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and an electric motor control module. The rotary unit includes a retaining seat and an oscillating seat. A lower wheel is pivotally connected to the retaining seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. A recess is formed on the oscillating seat. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The bearing is located in the recess. The electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. The electric motor is controlled to run or stop running to achieve the function of automatically adjusting the oscillating position of the abrasive belt through the abrasive belt position detector, the first sensor and the second sensor.

Inventors

  • Bor-Yann Chuang

Assignees

  • Bor-Yann Chuang

Dates

Publication Date
20260505
Application Date
20240403

Claims (8)

  1. 1 . A belt sander, comprising: a base, including at least one workbench thereon; a frame, disposed on one side of the base, the frame having a retaining bracket; a rotary unit, including a retaining seat and a motor, the retaining seat and the motor being fixed to the retaining bracket of the frame, a lower wheel being pivotally disposed on the retaining seat, the lower wheel being connected to the motor, one end of a central axle being fixed to the retaining seat, another end of the central axle being fixed to an oscillating seat, a recess being formed on the oscillating seat, an upper wheel being pivotally connected to the oscillating seat, an abrasive belt being mounted on the upper wheel and the lower wheel; an oscillating unit, including an electric motor, an eccentric bushing and a bearing, the electric motor being fixed to the retaining seat, the electric motor being connected to an output shaft, the output shaft having a receiving groove, the eccentric bushing being fitted on a periphery of the output shaft, the eccentric bushing and the output shaft being arranged eccentrically, the eccentric bushing having an accommodating groove corresponding to the receiving groove, a pin being inserted in the receiving groove and the accommodating groove, the bearing being fitted on the eccentric bushing and located in the recess; an abrasive belt position detector, disposed on the retaining seat for detecting a position of the abrasive belt; a first sensor and a second sensor, the first sensor and the second sensor being configured for confirming an oscillating angle of the oscillating seat; a control unit, including an electric motor control module, the electric motor control module being electrically connected to the abrasive belt position detector, the first sensor and the second sensor, thereby controlling the electric motor to run or stop running; wherein when the electric motor is running, the bearing is rotated eccentrically to drive the oscillating seat to move back and forth.
  2. 2 . The belt sander as claimed in claim 1 , wherein the abrasive belt position detector has a signal terminal and a reflection terminal, and a portion of the abrasive belt is between the signal terminal and the reflection terminal, thereby blocking or not blocking the abrasive belt position detector.
  3. 3 . The belt sander as claimed in claim 1 , wherein the eccentric bushing is located between the first sensor and the second sensor, a magnetic element is disposed on the eccentric bushing, and the first sensor and the second sensor detect a position of the magnetic element to confirm the oscillating angle of the oscillating seat.
  4. 4 . The belt sander as claimed in claim 3 , wherein the control unit includes an abrasive belt position detection module that is electrically connected to the abrasive belt position detector, a first oscillating angle detection module that is electrically connected to the first sensor, and a second oscillating angle detection module that is electrically connected to the second sensor; when the abrasive belt is in a blocking position and the first sensor does not detect the magnetic element, the electric motor control module controls the electric motor to run; when the abrasive belt is not in the blocking position and the second sensor does not detect the magnetic element, the electric motor control module controls the electric motor to run.
  5. 5 . The belt sander as claimed in claim 4 , wherein when the abrasive belt is in the blocking position and the first sensor detects the magnetic element or when the abrasive belt is not in the blocking position and the second sensor detects the magnetic element, the electric motor control module controls the electric motor to stop running.
  6. 6 . The belt sander as claimed in claim 1 , wherein the central axle has a retaining section, a retaining sleeve is fitted on the retaining section, the retaining sleeve is fixed to the retaining seat, a retaining rod is provided on one side of the retaining sleeve, and the retaining rod is fixed to the retaining seat.
  7. 7 . The belt sander as claimed in claim 1 , wherein an outer circumference of the central axle, close to the oscillating seat, has a retaining ring, and a spring is fitted on the central axle between the retaining ring and the retaining sleeve.
  8. 8 . The belt sander as claimed in claim 1 , further comprising a lifting adjustment unit, wherein the lifting adjustment unit includes a lifting rod, a rotary disk on one end of the lifting rod, and a handle on the rotary disk; the lifting rod has a detection section and a threaded section, a graduated sleeve is fitted on the detection section, the graduated sleeve and a detector are arranged oppositely, the detector is fixed to the frame for detecting a rotation angle of the graduated sleeve, and the threaded section is screwed to a transverse protrusion of the retaining bracket.

Description

FIELD OF THE INVENTION The present invention relates to a belt sander, and more particularly to, a belt sander capable of automatically adjusting the oscillating position of an abrasive belt. BACKGROUND OF THE INVENTION A belt sander is widely used for wooden products, furniture, and so on. The surface of wood has to be processed appropriately by sanding and polishing through the belt sander to enhance the overall appearance and fine modification. As disclosed in U.S. patent application Ser. No. 17/542,404, an oscillating device of a belt sander comprises rollers and wheels located on both sides of a belt sander. A motor drives the abrasive belt to rotate through the rollers, and an electric motor drives the wheels to oscillate left and right, so that the abrasive belt is reciprocated up and down, thereby improving the quality and efficiency of sanding or polishing. However, in the conventional belt sander, the wheels are oscillated through the electric motor, the output shaft, the linking member, the eccentric shaft and the frame, having the disadvantages of large number of components and high complexity of assembly. Besides, the difference in the circumference of the two sides of the abrasive belt leads to inconsistent tension, which in turn affects the oscillating position of the abrasive belt. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems. SUMMARY OF THE INVENTION The primary object of the present invention is to provide a belt sander capable of automatically adjusting the oscillating position of an abrasive belt. When the abrasive belt is reciprocated left and right, the oscillating position of the abrasive belt is automatically adjusted. In order to achieve the above object, the belt sander provided by the present invention comprises a base, a frame, a rotary unit, an oscillating unit, an abrasive belt position detector, a first sensor, a second sensor, and a control unit. The base includes at least one workbench thereon. The frame is disposed on one side of the base. The frame has a retaining bracket. The rotary unit includes a retaining seat and a motor fixed to the retaining bracket. A lower wheel is pivotally disposed on the retaining seat. The lower wheel is connected to the motor. One end of a central axle is fixed to the retaining seat. Another end of the central axle is fixed to an oscillating seat. A recess is formed on the oscillating seat. An upper wheel is pivotally connected to the oscillating seat. An abrasive belt is mounted on the upper wheel and the lower wheel. The oscillating unit includes an electric motor, an eccentric bushing, and a bearing. The electric motor is connected to an output shaft. The eccentric bushing and the output shaft are arranged eccentrically and fitted on a periphery of the output shaft. The bearing is fitted on the eccentric bushing and located in the recess. The abrasive belt position detector is disposed on the retaining seat for detecting a position of the abrasive belt. The first sensor and the second sensor are configured for confirming an oscillating angle of the oscillating seat. The control unit includes an electric motor control module. The electric motor control module is electrically connected to the abrasive belt position detector, the first sensor and the second sensor, thereby controlling the electric motor to run or stop running. In the belt sander provided by the present invention, the motor drives the abrasive belt to rotate, the electric motor drives the upper wheel to oscillate through the eccentric bushing and the bearing, and the abrasive belt is reciprocated left and right. Besides, the belt sander provided by the present invention has the ability to maintain the oscillating angle of the oscillating seat and automatically adjust the oscillating position of the abrasive belt through the abrasive belt position detection module, the first oscillating angle detection module and the second oscillating angle detection module. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a preferred embodiment of the present invention; FIG. 2 is an exploded view of the preferred embodiment of the present invention; FIG. 3 is a partial exploded view of the preferred embodiment of the present invention, illustrating the rotary unit and the oscillating unit; FIG. 4 is a partial cross-sectional view of the preferred embodiment of the present invention; FIG. 5 is another partial cross-sectional view of the preferred embodiment of the present invention, illustrating the lifting adjustment unit; FIG. 6 is a further partial cross-sectional view of the preferred embodiment of the present invention, illustrating the abrasive belt position detector; FIG. 7 is a block diagram of the control unit of the preferred embodiment of the present invention; FIG. 8 is a flowchart showing the control of the electric motor of the preferred embodiment of the present in