GRINDER
A grinder includes an attachment base provided on a main body, which is rotatably retaining a spindle, and surrounding the spindle; a mating portion provided on the wheel guard and mated with the attachment base; a recessed portion provided on the attachment base; a protruding portion provided on the mating portion; and a plate spring disposed between the attachment base and the mating portion, and when the wheel guard is displaced in the radial direction of the spindle against bias of the plate spring, mating between the recessed portion and the protruding portion is canceled, and the wheel guard is turnable in the circumferential direction of the spindle. As a result, the possibility that fixation of the wheel guard is cancelled against the intention of an operator is reduced as much as possible.
The present invention relates to a grinder to which a rotating tool is attached.
BACKGROUND ARTA grinder is provided with a spindle, which is subjected to a rotary drive, and various rotating tools are attached to the spindle depending on purposes and uses. For example, a disk-shaped grinding stone, a brush, a cutter, etc. are attached to the spindle of the grinder. The grinding stone to be attached to the spindle of the grinder includes a grinding stone for polishing and a grinding stone for cutting. The brush to be attached to the spindle of the grinder includes a wire brush and a wireless brush. The cutter to be attached to the spindle of the grinder includes a diamond cutter. In the below explanations, various rotating tools attached to the spindle may be collectively referred to as “wheel”.
The grinder as described above is required to attach a wheel guard that covers ½ or more the outer circumference of the wheel. Moreover, when the grinder is used, the attachment position of the wheel guard has to be changed depending on purposes and uses.
Therefore, Patent Document 1 describes a grinder in which the attachment position of the wheel guard can be changed without using a tool such as a wrench or a screwdriver. In the grinder described in Patent Document 1, the wheel guard is turnably attached to a packing gland. The packing gland is provided with a retaining groove, and a set ring of the wheel guard is provided with a rib, which is mated with the retaining groove. Furthermore, between the packing gland and the set ring, a coiled spring, which prevents the rib mated with the retaining groove from falling, is disposed.
In the grinder described in Patent Document 1 provided with the above described structure, when the wheel guard is pushed up to the axial-direction upper side of the spindle against bias of the coiled spring, the mating between the retaining groove and the rib is cancelled. Therefore, fixation of the wheel guard is cancelled, and the attachment position of the wheel guard can be changed. Then, when push-up with respect to the wheel guard is cancelled, the rib is mated with the retaining groove again by the bias of the coiled spring. Therefore, the wheel guard is fixed at a new attachment position.
RELATED ART DOCUMENT Patent DocumentPatent Document 1: Japanese Utility Model Application Publication Laid-Open No. H6(1994)-36764
SUMMARY OF THE INVENTION Problems to be Solved by the InventionIn the grinder described in Patent Document 1, when the wheel guard is pushed up to the axial-direction upper side of the spindle, the fixation of the wheel guard is cancelled. Herein, in many cases, the wheel attached to the grinder is retained approximately parallel to the surface of an object such as stone, concrete and wood and is pushed against the object surface. At this point, if the wheel guard contacts the object surface for some reason, the force which is upward in the axial direction of the spindle is applied to the wheel guard. In other words, the force that acts to cancel the fixation of the wheel guard is applied to the wheel guard. Therefore, the fixation of the wheel guard may be cancelled against the intention of the operator who is using the grinder.
An object of the present invention is to reduce, as much as possible, the possibility that the fixation of the wheel guard is cancelled against the intention of the operator.
Means for Solving the ProblemsA grinder of the present invention is provided with a spindle to which a rotating tool is attached and a wheel guard covering the rotating tool attached to the spindle, and the grinder includes: an attachment base provided on a main body rotatably retaining the spindle, the attachment base surrounding the spindle; a mating portion provided on the wheel guard and mated with the attachment base; a recessed portion provided on either one of the attachment base and the mating portion; and a protruding portion provided on the other one of the attachment base and the mating portion. Then, when the wheel guard is displaced in a radial direction of the spindle, mating between the recessed portion and the protruding portion is cancelled, and the wheel guard is turnable in a circumferential direction of the spindle.
In an aspect of the present invention, the grinder is provided with an elastic body disposed between the attachment base and the mating portion, and when the wheel guard is displaced in a radial direction of the spindle against bias of the elastic body, the mating between the recessed portion and the protruding portion is cancelled, and the wheel guard is turnable in the circumferential direction of the spindle.
In another aspect of the present invention, the recessed portion is provided on an outer circumferential surface of the attachment base, the protruding portion is provided on an inner circumferential surface of the mating portion, and the elastic body is provided on the inner circumferential surface of the mating portion and at a position opposed to the protruding portion.
In another aspect of the present invention, the elastic body is a plate spring curved toward an inner side of the mating portion.
In another aspect of the present invention, the main body includes: a housing a drive source of the spindle; and a gear case rotatably retaining the spindle. The attachment base is integrally formed with a cover member covering an opening of the gear case.
In another aspect of the present invention, the grinder is provided with a projecting portion projecting inward from the inner circumferential surface of the mating portion, and an engaging portion projecting outward from the outer circumferential surface of the attachment base and engaged with the projecting portion.
In another aspect of the present invention, the recessed portion is provided on the attachment base, and the engaging portion is provided in a region of the attachment base excluding a region in which the recessed portion is provided.
In another aspect of the present invention, a grinder is provided with an output shaft to which a rotating tool is attached, a wheel guard covering the rotating tool, and an attachment base to which the wheel guard is attached, and the grinder includes: a recessed portion provided on either one of the wheel guard and the attachment base; and a protruding portion provided on the other one of the wheel guard and the attachment base. Then, the recessed portion and the protruding portion are mated with each other in a radial direction of the output shaft.
In another aspect of the present invention, the grinder is provided with an elastic body disposed between the wheel guard and the attachment base in the radial direction of the output shaft, and biasing either one of the protruding portion and the recessed portion toward the other one of the protruding portion and the recessed portion.
In another aspect of the present invention, the wheel guard is provided with either one of the protruding portion and the recessed portion, the elastic body, and a perpendicular part covering a radial-direction outer side of the rotating tool. The perpendicular part is provided in a side in which the elastic body is provided in relation with the output shaft.
In another aspect of the present invention, either one of the protruding portion and the recessed portion, and the elastic body are provided at symmetrical positions with respect to the output shaft.
In another aspect of the present invention, a grinder includes: an output shaft to which a rotating tool is attached; a wheel guard provided with a mating portion and a perpendicular part covering the rotating tool; and an attachment base to which the mating portion is attached. The wheel guard is movable from the mating-portion side to the perpendicular-part side, and the mating portion and the attachment base are mated with each other in a moving direction of the wheel guard.
In another aspect of the present invention, the grinder is provided with a recessed portion provided on either one of the mating portion and the attachment base, and a protruding portion provided on the other one of the mating portion and the attachment base. The recessed portion and the protruding portion are disposed in an opposite side of the perpendicular part with respect to the output shaft.
In another aspect of the present invention, the grinder is provided with an elastic body biasing the wheel guard to the perpendicular-part side.
In another aspect of the present invention, the grinder is provided with an elastic body causing the recessed portion and the protruding portion to be mated with each other in a radial direction of the output shaft.
Effects of the InventionAccording to the present invention, the possibility that the fixation of the wheel guard is cancelled against the intention of the operator is reduced.
Hereinafter, an example of a grinder to which the present invention is applied will be explained in detail with reference to the drawings. As shown in
The grinder 1 is provided with a main body 5 including a housing 3 and a gear case 4. The housing 3 has an approximately cylindrical shape as a whole, and an electric motor 6 serving as a drive source is housed in the housing 3. The electric motor 6 is connected to a commercial electric-power source via an electric-power-source cord 7, which is extended from a rear end of the housing 3.
The gear case 4 has a case main body 10 and a packing gland 11 serving as a cover member, which covers an opening of the case main body 10, and is attached to a distal end of the housing 3. Two bearings (a needle bearing 12 and a ball bearing 13) are provided in the gear case 4, and a spindle (output shaft) 20 is rotatably retained by these bearings. The spindle 20 is orthogonal to an output shaft 6a of the electric motor 6, and one end thereof is penetrating through the packing gland 11 and projecting to the outside. On the other hand, a bevel gear 22, which is meshed with a bevel gear 21 attached to the output shaft 6a of the electric motor 6, is attached to the other end of the spindle 20 positioned in the gear case 4. The rotation direction of the electric motor 6 is converted by 90 degrees by the above-described pair of bevel gears and is transmitted to the spindle 20 with a reduced rotation speed. In other words, the spindle 20 is subjected to rotary drive by the electric motor 6.
The grinding wheel 2 is provided with a substrate 2a including a disk-shaped steel plate, and a plurality of diamond grinding stones are fixed to a surface of the substrate 2a by adhesion or another means. Moreover, an attachment hole into which the spindle 20 is inserted is provided at the center of the substrate 2a, and the grinding wheel 2 is attached to the spindle 20, which penetrates through the attachment hole. Specifically, the grinding wheel 2 is fixed to the spindle 20 by a wheel washer(s) and a lock nut(s), and rotated integrally with the spindle 20. The housing 3 is provided with an unshown switch. When this switch is operated, electric power is supplied to the electric motor 6, and the output shaft 6a of the electric motor 6 is rotated. As a result, the spindle 20 coupled to the output shaft 6a via the above-described pair of bevel gears is rotated, and the grinding wheel 2 fixed to the spindle 20 is rotated.
A wheel guard 30 covering at least ½ or more the outer circumference of the grinding wheel 2 is attached to the gear case 4. Hereinafter, an attachment structure of the wheel guard 30 will be explained in detail.
As shown in
On an outer circumferential surface of the attachment base 41, a plurality of recessed portions 42 are provided along the circumferential direction thereof at a constant interval. Specifically, as shown in
As shown in
As shown in
As shown in
As shown in
As shown in
Then, when the mating portion 32 (wheel guard 30) shown in
The position of the wheel guard 30 shown in
Then, while pushing (or pulling) with respect to the wheel guard 30 is maintained, the wheel guard 30 is turned by a desired angle to an arrow direction shown in
Then, when pushing (or pulling) with respect to the wheel guard 30 is cancelled, as shown in
In the present embodiment, when the wheel guard 30 shown in
However, as shown in
The present invention is not limited to the above described embodiment, and various modifications can be made without departing from the gist thereof. For example, the plate spring 34 serving as the elastic body can be replaced by a coiled spring, rubber, or the like. Moreover, the protruding portion 33 is only required to be provided on either one of the attachment base 41 and the mating portion 32, and the recessed portion 42 is only required to be provided on the other one of the attachment base 41 and the mating portion 32. Therefore, the protruding portion 33 can be provided on the attachment base 41, and the recessed portion 42 can be provided on the mating portion 32. Moreover, the protruding portion 33 is only required to be provided on either one of the wheel guard 30 and the attachment base 41, and the recessed portion 42 is only required to be provided on the other one of the wheel guard 30 and the attachment base 41. Furthermore, the number and disposition of the recessed portion 42 and the protruding portion 33 can be appropriately changed as necessary.
REFERENCE SIGNS LIST
- 1 GRINDER
- 2 GRINDING WHEEL
- 2a SUBSTRATE
- 3 HOUSING
- 4 GEAR CASE
- 5 MAIN BODY
- 6 ELECTRIC MOTOR
- 6a OUTPUT SHAFT
- 7 ELECTRIC-POWER-SOURCE CORD
- 10 CASE MAIN BODY
- 11 PACKING GLAND
- 12 NEEDLE BEARING
- 13 BALL BEARING
- 20 SPINDLE
- 21 BEVEL GEAR
- 22 BEVEL GEAR
- 30 WHEEL GUARD
- 30a HORIZONTAL PART
- 30b PERPENDICULAR PART
- 31 OPENING
- 32 MATING PORTION
- 33 PROTRUDING PORTION
- 34 PLATE SPRING
- 35 PROJECTING PORTION
- 40 THROUGH HOLE
- 41 ATTACHMENT BASE
- 41a ENGAGING PORTION
- 42, 42a RECESSED PORTION
- 43 RELIEF PORTION
Claims
1. A grinder provided with a spindle to which a rotating tool is attached and a wheel guard covering the rotating tool attached to the spindle, the grinder comprising:
- an attachment base provided on a main body rotatably retaining the spindle, the attachment base surrounding the spindle;
- a mating portion provided on the wheel guard and mated with the attachment base;
- a recessed portion provided on either one of the attachment base and the mating portion; and
- a protruding portion provided on the other one of the attachment base and the mating portion,
- wherein when the wheel guard is displaced in a radial direction of the spindle, mating between the recessed portion and the protruding portion is cancelled, and
- the wheel guard is turnable in a circumferential direction of the spindle.
2. The grinder according to claim 1, comprising an elastic body disposed between the attachment base and the mating portion,
- wherein when the wheel guard is displaced in a radial direction of the spindle against bias of the elastic body the mating between the recessed portion and the protruding portion is cancelled, and
- the wheel guard is turnable in the circumferential direction of the spindle.
3. The grinder according to claim 2,
- wherein the recessed portion is provided on an outer circumferential surface of the attachment base,
- the protruding portion is provided on an inner circumferential surface of the mating portion, and
- the elastic body is provided on the inner circumferential surface of the mating portion and at a position opposed to the protruding portion.
4. The grinder according to claim 3,
- wherein the elastic body is a plate spring curved toward an inner side of the mating portion.
5. The grinder according to claim 1,
- wherein the main body includes: a housing housing a drive source of the spindle; and a gear case rotatably retaining the spindle, and
- the attachment base is integrally formed with a cover member covering an opening of the gear case.
6. The grinder according to claim 1, comprising:
- a projecting portion projecting inward from the inner circumferential surface of the mating portion; and
- an engaging portion projecting outward from the outer circumferential surface of the attachment base and engaged with the projecting portion.
7. The grinder according to claim 6,
- wherein the recessed portion is provided on the attachment base, and
- the engaging portion is provided in a region of the attachment base excluding a region in which the recessed portion is provided.
8. A grinder provided with an output shaft to which a rotating tool is attached, a wheel guard covering the rotating tool, and an attachment base to which the wheel guard is attached, the grinder comprising:
- a recessed portion provided on either one of the wheel guard and the attachment base; and
- a protruding portion provided on the other one of the wheel guard and the attachment base,
- wherein the recessed portion and the protruding portion are mated with each other in a radial direction of the output shaft.
9. The grinder according to claim 8, comprising an elastic body disposed between the wheel guard and the attachment base in the radial direction of the output shaft, and biasing either one of the protruding portion and the recessed portion toward the other one of the protruding portion and the recessed portion.
10. The grinder according to claim 9,
- wherein the wheel guard is provided with either one of the protruding portion and the recessed portion, the elastic body, and a perpendicular part covering a radial-direction outer side of the rotating tool, and
- the perpendicular part is provided in a side in which the elastic body is provided in relation with the output shaft.
11. The grinder according to claim 10,
- wherein either one of the protruding portion and the recessed portion, and the elastic body are provided at symmetrical positions with respect to the output shaft.
12. A grinder comprising:
- an output shaft to which a rotating tool is attached; a wheel guard provided with a mating portion and a perpendicular part covering the rotating tool; and
- an attachment base to which the mating portion is attached,
- wherein the wheel guard is movable from the mating-portion side to the perpendicular-part side, and
- the mating portion and the attachment base are mated with each other in a moving direction of the wheel guard.
13. The grinder according to claim 12, comprising:
- a recessed portion provided on either one of the mating portion and the attachment base; and
- a protruding portion provided on the other one of the mating portion and the attachment base,
- wherein the recessed portion and the protruding portion are disposed in an opposite side of the perpendicular part with respect to the output shaft.
14. The grinder according to claim 13, comprising an elastic body biasing the wheel guard to the perpendicular-part side.
15. The grinder according to claim 13, comprising an elastic body causing the recessed portion and the protruding portion to be mated with each other in a radial direction of the output shaft.
Type: Application
Filed: Jul 25, 2014
Publication Date: Jul 7, 2016
Inventor: Yuuki TAKEDA (Ibaraki)
Application Number: 14/912,237