JPH04128154U - belt sander - Google Patents

Abstract

(57) [Summary] [Purpose] When grinding a flat surface to be ground, it is possible to push the entire surface of the paper belt onto the surface to be ground without the hand holding the belt sander touching the material to be ground. To provide a belt sander that can give a beautiful finished surface and perform efficient grinding work. [Structure] The paper belt 90 is configured to be attached in a triangular shape by passing over the drive pulley 61, middle pulley 81, and tension pulley 71.
When the entire grinding surface 90a of the paper belt located between the paper belt 1 and the tension pulley 71 comes into contact with the workpiece W, a certain gap is created between the workpiece W and the motor case 30. It is assumed that the configuration is formed.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is suitable for belt sanders, which are suitable for grinding stone products, etc. It is related to

0002

[Conventional technology]

A commonly used belt sander a is, for example, as shown in Figure 10. It was composed of This belt sander a has a first pulley d attached to the output shaft s of an air motor m, for example. A support arm e is provided which is directly connected to the first pulley d and extends in a direction perpendicular to the first pulley d. , a distal end of the support arm e is provided at a predetermined distance from the first pulley d. The second pulley b is supported in parallel, and an endless paper belt is placed between both pulleys d and b. It is constructed by spanning the root p. Then, air is passed through the air hose h. If compressed air is supplied to motor m, this air motor m will rotate at high speed, which causes An example of this paper belt p is obtained by moving the paper belt p in a certain direction at high speed. For example, grinding is performed by pressing the lower grinding surface pa against the material W to be ground, such as a stone product. be.

0003 This belt sander a has an adjustment function for adjusting the tension of the paper belt p. Or, in order to replace this paper belt p, for example, as shown above, Insert an adjustment nut c in the middle of the support arm e, and rotate this adjustment nut c. It is configured so that the distance between the axes between both pulleys d and b can be increased or decreased by Met.

0004

[Problem that the idea aims to solve]

However, the conventional belt sander a has the following problems. That is, the paper belt p of this belt sander a is connected to the first pulley d and the second pulley. Since it is installed across the two shafts of Lee B, it is constructed as shown in Figure 11. When a trader grips this belt sander a and grinds the flat part of the material to be ground W, and press the grinding surface pa of the paper belt p against the workpiece W across the entire surface. If so, your hand will touch the workpiece W first, so you have no choice but to touch the tip of the grinding surface pa. This forces you to press only the edges, which is not only inconvenient to use, but also makes it difficult to finish the work efficiently. It was difficult to perform good grinding work on the raised surface.

[0005] In addition, for example, in the actual grinding work of stone products, the Rinse off the grinding powder (stone powder) from time to time to check the finish, and also check the finished product after washing it off. Work is performed by blowing compressed air to remove moisture or grinding powder on the rising surface. For this purpose, provision must be made for water supply, for example by means of a hose. Furthermore, a separate compressed air injection device (for example, commonly known as air It was very troublesome to have to prepare a gun.

[0006] This invention was made to solve these conventional problems, and is easy to use. Efficient grinding work can be carried out, and water supply equipment or compressed air injection equipment can also be used. Grinding work can be made even more efficient by installing the machine or both together. The purpose is to provide a belt sander that can perform

[0007]

[Means to solve the problem]

In order to solve the above-mentioned problems, this invention is designed to solve the above problems by installing a A drive pulley rotated by a motor driven by a motor, and a triangle with the drive pulley at its apex. A middle pulley and a tension pulley are provided at both ends of the bottom of the paper base. The belt is constructed to be installed in a triangular shape by spanning between each pulley. The grinding surface of the paper belt located between the pulley and the tension pulley is When the entire surface comes into contact with the material to be ground, the contact between the material to be ground and the motor case A certain gap is formed between the water supply device or the compressed air injection device. or both, to supply water and/or compressed air to the paper base. It is characterized by a structure in which a balloon can be blown out near the root.

[0008]

[Effect]

According to the above configuration, the motor case is held almost parallel to the material to be ground and When the entire grinding surface of the belt is pressed against the workpiece, the motor A certain gap is created between the case and the material to be ground, and the hand holding the motor case does not touch the material to be ground.

[0009] Also, the water supply device or compressed air injection device is not attached to the belt sander. There is no need to prepare it separately.

0010

【Example】

Next, an embodiment of the present invention will be described based on FIGS. 1 to 9. In addition, in this example, a bell whose driving source is an air motor M rotated by compressed air is used. This will be explained using Tosander A as an example. FIG. 1 is a longitudinal sectional view of the entire belt sander A of this example, and FIG. 2 is a side view thereof. , FIG. 3 is a front view, and FIG. 4 is a rear view.

[0011] In the figure, 30 is a motor case, which has a roughly cylindrical shape with an appropriate diameter that is easy for the operator to grasp. It is formed to also serve as the grip part of belt sander A in this example. Ru. An air motor M is installed in the left side of the motor case 30 in the drawing.

0012 Since this air motor M is already known, the explanation will be omitted. Connected to the rear end of the motor case 30 on the right side in the figure via the hose joint 1. It is configured to be rotatable by compressed air supplied by an air hose 4. Ru. Note that the air hose 4 is connected to a compressed air supply device (not shown).

[0013] The compressed air supplied via the air hose 4 passes through the air passage 10 to the air motor. -M, but there is a straight bar in the middle of this air passage 10. Lube 3 is interposed. This straight valve 3 is connected directly to the motor case 30. It is rotatable in the radial direction so as to cross the air passage 10 and the water channel 9 described later. It is supported by Noh. In the diametrical direction of this straight valve 3, air is Communication holes 3b and 3c are formed to penetrate through the channel 10 and the water channel 9, respectively. Then, rotate the knob 5 attached to the tip of this straight valve 3 to By disconnecting the air passage 10, it is possible to switch between driving and stopping the air motor M. has been completed. Here, the water channel 9 and the communication hole 3c constitute a water supply device. This will be discussed later.

[0014] In the figure, 31 is a case cover made of synthetic rubber, for example, and the motor case 30 The motor case 30 is attached to the outer peripheral surface of the belt sander A. It is constructed so that it can be easily held as a cup.

[0015] Furthermore, as shown in FIG. 4, a silencer 14 is attached to the rear end of the motor case 30. The exhaust from the air motor M passes through this silencer 14. is constructed so that it is exposed to the atmosphere.

[0016] Next, on the left end side of the motor case 30 configured in this way, there is a drive. A gear case 50 is attached to which a shaft 59 is rotatably supported. child A cylindrical flange portion 50a is formed protruding from the left side surface of the gear case 50 in the figure. , the drive shaft 59 protrudes from the cylindrical flange portion 50a to the left in the figure. It is supported by On the other hand, inside this gear case 50 is the output of the air motor M. A shaft 33 protrudes, and a gear 33a is formed at the tip of this output shaft 33. Ru. This gear 33a is connected to a spatula attached to the rear end of the drive shaft 59. - is meshed and connected to the gear 54, thereby controlling the rotation of the air motor M. It is configured to be transmitted to the eve shaft 59.

[0017] Furthermore, a drive pulley 61 is attached to the tip of the drive shaft 59. It is being This drive pulley 61 is movable in the axial direction of the drive shaft 59. The compression coil is attached to the drive shaft 59 and is interposed between the drive shaft 59 and the drive shaft 59. It is biased to the right in the figure by a spring 62.

[0018] A flange 61c is formed at the rear end of this drive pulley 61 (the right end in FIG. 1). There is a rubber anti-slip on the outer circumferential surface of the belt hanging part in front of the flange 61c. A cover 63 is attached.

[0019] In addition, the rear end surface of this drive pulley 61 (see FIG. 5) has two recesses with different depths. The grooves 61a and 61b (hereinafter referred to as "shallow groove 61a" and "deep groove 61b") are approximately The drive shaft 59 is formed to be orthogonal to each other, while the drive shaft 59 has a shaft that protrudes on both sides in the diametrical direction. Locking protrusions 59a, 59a are formed to bias the compression coil spring 62. The drive pulley 61 is moved to the left in the figure against the force, and the groove 61a (or 61b) is moved. If the locking protrusions 59a, 59a are removed from the drive shaft, the drive pulley 61 59, and conversely, due to the biasing force of the compression coil spring 62, the The protrusion 59a moves to the right and engages one of the grooves 61a (or 61b). 59a, this drive pulley 61 will rotate relative to the drive shaft 59. It is configured so that it cannot rotate as a unit. And both concave grooves 61a, 61 b have different depths, so the locking protrusions 59a, 59a are inserted into the shallow groove 61a. If the driver is inserted into the deep concave groove 61b, the drive force will be increased by the difference in depth between the two. It will be held on the tip side of the eve shaft 59.

[0020] In this way, the drive pulley 61 is moved to the left in the figure and made rotatable. By selecting the concave groove into which the locking protrusion 59a of the shaft 59 is inserted, the drive plate The drive shaft 59 is configured so that it can be held at two selected positions in the axial direction of the drive shaft 59. It is being done.

[0021] Next, as shown in FIGS. 2 to 4 (or FIG. 6), the lower part of the gear case 50 is The support edge 50b is formed to extend, and the front side of the support edge 50b (in FIG. 2) A middle pulley 81 is rotatably attached to the left side) via a support shaft 50c. It is being This middle pulley 81 has approximately the same diameter as the drive pulley 61. It is formed to have the same width as the belt hanging part of the belt, and is connected to the drive pulley 61. The guide pulley 61 maintains its position in parallel and on its tip surface via the deep groove 61b. It is supported so that it is aligned with the tip surface when held. The outer peripheral surface of this middle pulley 81 is also made of rubber, similar to the drive pulley 61 described above. A non-slip cover 83 is attached.

[0022] Next, an eccentric collar is provided on the outer peripheral side of the cylindrical flange portion 50a of the gear case 50. 65 is fitted, and a tension arm 7 is fitted on the outer circumferential side of this eccentric collar 65. 0 is attached.

[0023] The eccentric collar 65 is formed in a ring shape with an outer circumference eccentric by a predetermined dimension with respect to an inner circumference. A screw hole 65a is formed on the circumferential side of the screw hole 65a passing through the inner circumferential side. A fixing screw 66 is attached to this screw hole 65a. And this fixing screw 6 6, the eccentric collar 65 can be rotated relative to the cylindrical flange portion 50a. It is configured so that it can be fixed by tightening it in the opposite direction.

[0024] The tension arm 70 is formed by forming a band plate into an arm shape of a predetermined length. With the eccentric collar 65 fitted into the support hole 70a formed at one end thereof, Rotatably supported. As a result, this tension arm 70 is on a plane perpendicular to the rotation axis of the drive shaft 59, that is, the drive pulley 61. Supported in a swingable manner. Further, a long groove hole is provided at an appropriate position on the side surface of the support hole 70a. 70c is formed, and a fixing screw having a knob 63 at the tip is inserted into this long slot 70c. The fixing screw 67 is inserted into the screw hole formed in the eccentric collar 65. It is attached to 65b. Then, by loosening this fixing screw 67, this tension can be adjusted. The rotation arm 70 can be swung relative to the eccentric collar 65; conversely, it can be swung by tightening it. configured to be permanently fixed.

[0025] Furthermore, the swinging tip side of this tension arm 70 is shown in FIG. 1 (or FIG. 2). A cut groove is formed from the side of the plate to divide it into two in the thickness direction, and the front A tension pulley is connected to the tip of the split arm 70b on the side (left side in the figure) via a support shaft 76. A relay 71 is rotatably attached. This tension pulley 71 is formed almost similarly to the middle pulley 81 described above. parallel to the middle pulley 81 and with its tip surfaces aligned. It is supported by In addition, the entire outer periphery of the pulleys 61 and 81 have the same A rubber anti-slip cover 73 is attached. Reference numeral 69 in the figure is an adjustment screw, and by rotating this adjustment screw 69, the above-mentioned tension can be adjusted. The rotation axis of pulley 71 is always aligned with the rotation axis of other pulleys 61 and 81. It is configured to be adjustable so that it is parallel to the

[0026] Between each pulley 61, 71, 81 supported in parallel with each other as described above, , as shown in FIGS. 1 to 3, the endless paper belt 90 forms a substantially triangular shape. It is worn across the sea urchin. The outer peripheral surface of this paper belt 90 is, for example, a It is coated with fine diamond particles and is capable of grinding stones, etc.

[0027] In addition, 105 in the figure is a protective cover made of synthetic resin, for example, and is a paper belt. 90 to prevent the scattering of grinding powder or water, etc., which will be described later. In order to ensure safety and good workability, the page should be removed from the top surface 50d of the gear case 50. It is attached so as to protrude above the par belt 90.

[0028] The configuration described above is the main body of the belt sander A of this example, and the air hose 4 The air motor M rotates at high speed due to the compressed air supplied by the The paper belt 90 is transmitted to the dynamic pulley 61 and moves in a fixed direction at high speed. This paper belt 90 mainly consists of a middle pulley 81 and a tension pulley. The part located between the grinding surface 90a (hereinafter referred to as the "grinding surface 90a") is It is configured so that it can grind the material W to be ground by pressing it against the material W to be ground, such as a material product. -ing

[0029] Next, the belt sander A configured as described above includes a water supply device and a compression device. An injection device is attached. First, the water supply device prevents clogging of the paper belt 90 and burns the material W to be ground. Prevents adhesion, and also removes grinding powder, etc. that adheres to the paper belt 90 or the material to be ground W. A device for supplying water to wash away Water is placed at the rear end of the water channel 9 formed in the motor case 30 (rear end of the motor case). While the cock 7 is attached and the hose 6 is connected, a water pipe is connected to the other end of the water channel 9. Connect the water pipe 111 to the outside of the motor case 30. It extends along the paper belt 90 almost directly above it. This war A water nozzle 114 is attached to the tip of the water pipe 111.

[0030] Further, the above-mentioned straight valve 3 is also interposed at a midway position of the water channel 9. There is. A communication hole 3c for the water channel 9 is formed in the diametrical direction of the straight valve 3. The straight valve 3 is rotated via the knob 5 to open the waterway. 9 can be communicated or cut off to switch between water supply and water cutoff. child Here, the water passage communication hole 3c is shaped in the same direction as the air passage communication hole 3b. Therefore, the above switching between water supply and water cutoff is performed by starting and stopping the air motor M. This is done in conjunction with the stop. In other words, at the same time as the air passage 10 is communicated, the water channel 9 is also communicated. When the air passage 10 is blocked, the water channel 9 is also blocked. It is.

[0031] Note that the water cock 7 is equipped with a knob 7a for adjusting the flow rate. By rotating the valve 7a, the water supply amount can be adjusted, and the water supply or water cutoff can be turned off. It is constructed so that it can be replaced. Also, the other end of the hose 6 is not shown. However, for example, it is connected to a water faucet.

[0032] Next, the compressed air injection device is injected with grinding powder during grinding work or the water supply device mentioned above. It is attached to blow away spilled water, etc., as shown in Figure 1 or Figure 4. In order to branch the air passage 10 to the rear end of the air passage 10 (from the straight valve 3) Connect the air pipe 101 to the hose joint 1 side), and is attached to the side of the gear case 50 along the outside of the motor case 30. It is connected to an air valve 91. And from this air valve 91, paper An air nozzle 102 extending close to the belt 90 is attached.

[0033] The air valve 91 is operated by a lever 93 and a compression coil spring 95 as shown in FIG. and a switching rod 94 that is biased upward in the figure. For example, if you push down the switching rod 94 with your finger, the air pipe 101 and air Compressed air is blown out from the air nozzle 102 by communicating with the nozzle 102, and vice versa. If you remove your finger from the lever 93 to make it free, the switching lock will open. The air pipe 101 is moved upward by the biasing force of the compression coil spring 95. communication with the air nozzle 102 is cut off, and the blowing of compressed air is stopped. It is configured. In other words, this compressed air injection device requires only switching of the straight valve 3. That is, independent of starting and stopping of the air motor M, compressed air is applied near the paper belt 90. It is constructed so that air can be blown out.

[0034] Belt sander A in this example is configured as described above, and with this configuration, In other words, it has the following effects.

[0035] First, to use this belt sander A, just operate as follows. That is, the air hose 4 connected to the compressed air supply device (not shown) In addition to supplying compressed air into the air passage 10, a water supply connected to a water faucet, etc. Water is supplied into the water channel 9 by the data hose 6. At this time, the flow rate of water cock 7 The adjustment knob 7a may be left open as appropriate.

[0036] After achieving this state, the operator grasps the motor case 30 and pulls the motor through the knob 5. When the tray valve 3 is rotated to the starting side, the air passage 10 and the water channel 9 are communicated with each other. As soon as the air motor M starts, water flows out from the water nozzle 114. . Thereby, the grinding work can be performed while flowing water onto the material W to be ground.

[0037] If water supply is not required, close the water cock 7 by turning the flow rate adjustment knob 7a. Turn the same knob 7a to turn on or off the water as needed. All you have to do is adjust the amount of water supplied.

[0038] The actual grinding work is mainly carried out on the grinding surface 90a (mirror surface 90a) of the paper belt 90. The part located between the dollar pulley 81 and the tension pulley 71) is the part to be ground. This is done by pressing the grinding surface 90a against the drive pulley 61. It is located at the base of the triangle defined as a point, and between it and the lower end of the motor case 30 in the illustration. A certain level difference (gap) is provided between the two. Therefore, as shown in FIG. 8, the motor case 30 is approximately The worker's hands do not touch the workpiece W even when held in parallel, and the paper Grinding work can be performed by pressing the belt's grinding surface 90a against the workpiece W over the entire surface. It is easy to use, has a beautiful finished surface, and is highly efficient. Good grinding work can be done easily.

[0039] Furthermore, belt sander A in this example is equipped with a water supply device, so it is easy to carry out grinding work. There is no need to prepare separately in advance, and if the water cock 7 is opened, the Water flows out from the water nozzle 114 at the same time as the amotor M starts, so the work The operator should hold this belt sander A with one hand and perform the grinding work while running water. This allows for efficient grinding work.

[0040] This belt sander A is also equipped with a compressed air injection device, which can be used separately. There is no need to mean it. And, regardless of whether the air motor M starts or stops, the air valve When the lever 93 of 91 is pressed, compressed air is injected from the air nozzle 102, and this operation This can be done with one hand while holding the belt sander A.

[0041] As described above, according to the belt sander A of this example, the water supply device or the compressed air injection There is no need to prepare a separate device, and there is no need to grip the belt sander A, prevent water from flowing out or All compressed air injection can be performed with one hand, and this belt sun is also useful in these respects. The grinder A is very easy to use, and grinding work is done efficiently.

[0042] Next, a procedure for replacing the paper belt 90 will be explained with reference to FIG. That is, if the fixing screw 67 is loosened, the tension arm 70 can be moved within the range of the long groove hole 70c. The tension arm 70 can be swung toward the middle pulley 81. By reducing the distance between the tension pulley 71 and middle pulley 81, The super belt 90 can be removed, and the tension arm 70 can be removed after replacement. The tension pulley 71 and middle pulley 81 swing toward the opposite side of the middle pulley. Appropriate tension can be applied to the paper belt 90 by increasing the distance between the axes of the paper belt 90. It can be installed in a stretched state between each pulley 61, 71, and 81. Wear.

[0043] Here, a tension pulley is selected so that the tension of the paper belt 90 is appropriate. The position of the belt 71 is not constant due to variations in the overall length of the paper belt. sand That is, the position of the grinding surface 90a of the paper belt is not constant. But long Also, the ease of use when holding this belt sander A (air valve 91, knob 5, etc.) Considering the ease of gripping when considering the arrangement of For example, it is desirable to always be parallel to the upper surface 50d of the gear case 50.

[0044] Therefore, in the belt sander A of this example, the swing center of the tension arm 70 is moved. This absorbs variations in the overall length of the paper belt and improves the grinding surface 90a. It is constructed so that it can always be positioned parallel to the upper surface 50d of the gear case 50. It is being accomplished. That is, the tension arm 70 rotates the eccentric collar 65. It is swingably supported by the cylindrical flange portion 50a of the gear case 50 through the Since the eccentric collar 65 is formed so that the inner circumference is eccentric with respect to the outer circumference, the fixing screw 66 and rotate this eccentric collar 65 by a predetermined angle. The center of swing of the arm 70 will move. In addition, loosen the fixing screw 66. When installing, remove the fixing screw 67 and attach the tension arm 70 to the drive shaft 59. This can be done by moving it toward the tip side.

[0045] In this way, the tension arm 70 is adjusted to fit the entire length of the paper belt 90. By moving the center of swing, the grinding surface 90a is aligned with the upper surface 50d of the gear case 50. The belt sander A of this example can also be positioned parallel to the This makes it easy to use.

[0046] Next, as explained above, according to the belt sander A of this example, the entire grinding surface 90a is Grinding work is possible by pressing the surface against the workpiece W, but in actual grinding work is often used by pressing only the end of the grinding surface 90a (see Fig. 11). Therefore, in general, the widthwise ends of the paper belt decrease most quickly. Here, da Paper belts coated with diamond particles are very expensive. Therefore, it is uneconomical to frequently replace them with new ones. Therefore, paper-based It is common practice to cut off the end of the root and reuse it by reducing its width. It is.

[0047] Belt sander A in this example is also compatible with this narrower paper belt 90'. It is possible. That is, as shown in FIG. 9, the drive pulley 61 is connected to the drive shaft. 59 to the distal end side, this narrow paper belt 90' can be The tip edge of is almost aligned with the tips of middle pulley 81 and tension pulley 71. state, and this paper belt 90' is brought into contact with the flange 61c of the drive pulley 61. It can be installed in the same position. From this, both pulleys 8 during grinding work. The tip of No. 1, 71 protrudes from the tip edge of the paper belt 90' and directly attaches to the material to be ground. This narrow paper belt 90' will not be damaged by being pressed against W. Even if there is, grinding work can be carried out without any problem.

[0048] Note that the movement of the drive pulley 61 is performed as follows. First, the drive pulley 61 is moved against the compression coil spring 62 and the drive shaft 59 is moved. The locking protrusion between the deep groove 61b and the drive shaft 59 The engagement with the pieces 59a, 59a is released. As a result, the drive pulley 61 becomes dry. It becomes possible to rotate with respect to the shaft 59. In this state, drive pulley 61 should be rotated approximately 90 After rotation, the biasing force of the compression coil spring 62 returns it to the right in the figure. This results in , the locking protrusions 59a, 59a are inserted into the shallow groove 61a, and the drive pulley 61 is displaced toward the tip of the drive shaft 59 by the difference in depth between the grooves 61a and 61b. It is maintained as such.

[0049] In this way, by displacing the drive pulley 61, the width of the paper becomes narrower. -Always align belt 90' with the ends of tension pulley 71 and middle pulley 81. Grinding work can be carried out in a stable state. From this, narrow paper bells Grinding work can be done without any problem even if the belt is 90', making the paper belt effective. This makes it possible to use it for

[0050] The belt sander A described above is an embodiment of the present invention, and its configuration is is not limited to what is explained above, and is outside the scope of claims for utility model registration. Various embodiments can be implemented within the scope.

[0051]

[Effect of the idea]

Since the present invention has the above configuration, the belt sander is placed parallel to the material to be ground. Even if you hold it and press the entire surface of the grinding surface against the workpiece, your hands may not touch the workpiece. It is easy to use because there is no touching, and therefore the finished surface is good and the efficiency is high. Can do good grinding work.

[0052] In addition, the water supply device and compressed air injection device are attached to the belt sander. This not only eliminates the need for separate equipment, but also allows the operator to flush the water with one hand. Grinding work can be done while blowing sand or compressed air. It is convenient and can also improve the efficiency of grinding work.

[0053] Furthermore, by moving the swing center of the tension arm, the paper belt It is possible to absorb variations in the overall length of the grinding surface when the operator grips it. The drive pulley can be kept in the proper orientation at all times, and the drive pulley cannot be displaced. It can also be used with narrower paper belts, making it easier to use paper belts. This makes it possible to use resources effectively.

[0054]

[Brief explanation of drawings]

FIG. 1 is a vertical sectional view of the entire belt sander according to an embodiment of the present invention.

FIG. 2 is a side view of the belt sander.

FIG. 3 is a view taken in the direction of arrow III in FIG. 2, and is a front view of the belt sander.

4 is a view taken along arrow IV in FIG. 2 and a rear view of the belt sander; FIG.

FIG. 5 is a rear view of the drive pulley.

FIG. 6 is a front view of the gear case and a plan view showing the positional relationship between the eccentric collar and the tension arm.

FIG. 7 is a partial vertical sectional view of the air valve.

FIG. 8 is an explanatory diagram of an example of use of the belt sander.

FIG. 9 is a partial cross-sectional view of the tip of the belt sander,
It is an explanatory view showing a displacement method of a drive pulley.

FIG. 10 is an overall perspective view showing a conventional example of a belt sander.

FIG. 11 is an explanatory diagram of an example of use of a conventional belt sander.

[Explanation of symbols]

A, a Belt sander W Material to be ground M, m air motor 30 Motor case 50 gear case 59 Drive shaft 59a Locking protrusion 61 Drive pulley 61a Shallow groove 61b Deep groove 65 Eccentric collar 70 Tension arm 71 Tension pulley 81 Middle pulley 90, p paper belt 90a, pa ground surface 102 Air nozzle 105 Protective cover 114 Water nozzle

Claims (5)

[Scope of utility model registration request] Claim 1: A paper belt is provided with a drive pulley rotated by a motor installed in a motor case serving as a gripping part, and a middle pulley and a tension pulley at both ends of the base of a triangle with the drive pulley as the apex. The paper belt is installed in a triangular shape by being stretched between pulleys, and when the entire grinding surface of the paper belt located between the middle pulley and the tension pulley is brought into contact with the material to be ground, A belt sander characterized in that a certain gap is formed between the material to be ground and the motor case. 2. The tension pulley is pivotally supported on a swinging tip side of a swingably supported tension arm,
The belt sander according to claim 1, wherein the distance between the shafts of the drive pulley or the middle pulley can be changed. 3. The tension arm is configured to be swingably supported through a support hole formed on the swing base side thereof, and an eccentric collar is interposed on the inner peripheral side of the support hole. 3. The belt sander according to claim 2, wherein the center of swing of the tension arm can be displaced by rotating the eccentric collar by a certain angle. 4. The belt sander according to claim 2, wherein the drive pulley is configured to be able to be displaced in the axial direction and held at a plurality of positions. 5. The belt sander according to claim 1, further comprising a water supply device and/or a compressed air injection device so that water and/or compressed air can be blown into the vicinity of the paper belt.