JPH05237807A - Router - Google Patents

Abstract

PURPOSE: To facilitate adjustment of cut depth by providing an adjustment ring of split structure engaging with a circumferential thread formed on a motor housing as an adjustment mechanism of cut depth of a router, and rotatably supporting this by the base of the motor housing through balls. CONSTITUTION: A motor housing 12 including a motor is mounted on a base 20 provided with a pair of handles 22 so that a cutting blade installed on the motor extends lower than the lower supporting face 24 of the base 20, and a cutting motion by the router 10 is carried out with the lower supporting face 24 on the upper face of a workpiece. As an adjustment mechanism of cut depth of this router 10, an adjustment ring 32 of split structure engaged with a circumferential thread 28 formed on the motor housing 12 is provided, the motor housing 12 is displaced in the longitudinal direction against the base 20 by rotating the adjustment ring 32 through balls 60, and the adjustment ring 32 is fixed to the motor housing 12 and the base 20 by the action of a tightening mechanism 39 after adjustment of the cut depth.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable electric grooving tool (hereinafter referred to as "router"), and more particularly to a cutting depth adjusting mechanism for a router.

[0002]

2. Description of the Related Art The present applicant has already proposed a router having a cutting depth adjusting mechanism composed of an adjusting ring in the patent application No. 784351 of 1992. This router is
It is composed of a router base part whose relative rotational movement is restricted and a motor housing. And the adjustment ring
Engages with the outer peripheral threads formed on the motor housing,
Moreover, it is provided so as to rotatably engage with the router base. More specifically, an annular groove is formed on the outside of the router base, and a protrusion that engages with this annular groove is formed on the adjustment ring, so that the adjustment ring moves on the router base around the longitudinal axis of the router. It can be rotated. Here, it is preferable that the adjusting ring is a plastic integrally-molded member including two substantially semi-cylindrical portions joined by a hinge structure. If the router base is made of the same material as the adjustment ring, the adjustment ring can be rotated relative to the router base with relatively little friction, and the adjustment ring will not wear excessively. Absent.

[0003]

However, when the router base is made of metal, a frictional force is generated between the protrusion of the adjusting ring and the wall of the annular groove of the router base. As a result, not only is it difficult to rotate the adjustment ring freely, but the protrusions of the adjustment ring are excessively worn. The present invention has been made in view of the above problems, and an object thereof is to provide a router base and an adjusting ring in the above-mentioned type of router even when the router base is made of a metal material and the adjusting ring is made of a plastic material. It is an object of the present invention to provide a mechanism capable of engaging with each other with relatively little friction.

[0004]

In order to achieve the above object, the present invention comprises: (a) a base portion having an annular groove on the outer periphery,
(B) An adjusting ring for setting a cutting depth of the router, which has a protrusion for engaging with an annular groove of the base and is provided rotatably around the longitudinal axis of the router with respect to the base. The adjustment ring is (1) a plurality of cavities formed in the protrusion, each cavities including a first opening communicating with an annular groove of the base; A ball having a second opening communicating with the outside of the adjusting ring; and (2) a plurality of balls, each ball being disposed in each cavity of the plurality of cavities, and having a size of each ball. Smaller than the second opening of each cavity and larger than the first opening,
(3) Each of the plurality of balls is held in each corresponding cavity, and a part of the ball is projected from the first opening of each cavity, and the ball is projected into the annular groove of the base. Holding means for contacting one wall, the holding means being located between the first and second openings of each cavity. There is.

[0005]

The router according to the present invention is provided with the adjusting ring for setting the cutting depth. Such a router includes a router base having an annular groove on the outer peripheral surface thereof, and the adjusting ring is formed with a protrusion for engaging with the annular groove of the router base. Such a structure allows the adjusting ring to rotate on the router base about the longitudinal axis of the router. In the present invention, a plurality of cavities or depressions are formed on the protrusion of the adjustment ring. Each cavity has a first opening communicating with a groove formed in the router base and a second opening communicating with the outside of the adjustment ring. In each cavity,
One ball is placed. The ball is smaller than the size of the second opening, but larger than the size of the first opening. Holding means for holding the ball in the cavity is provided between the first and second openings in each cavity. By this holding means, the ball is held so that a part thereof contacts the wall of the groove of the router base through the first opening. The balls thus provided on the protrusions of the adjusting ring come into contact with the walls of the grooves of the router base to form a ball bearing structure. The protrusion of the adjusting ring and the groove of the router base are engaged with each other in a frictionless state by the ball bearing structure.

[0006]

The present invention will be described in detail below.

The router of the present invention is provided with a cutting depth adjusting mechanism which engages with an outer peripheral thread formed on the motor housing of the router and also on the router base. It consists of an adjusting ring rotatably engaged.
Here, in order to rotatably provide the adjusting ring with respect to the router base, the router base is formed with an annular groove, and the adjusting ring is formed with a projection for engaging with the annular groove. A plurality of cavities or pockets are formed in this protrusion, and an opening communicating with the annular groove is formed in each pocket. A ball is held in each pocket. Here, the ball is held so as to project from the opening of each pocket and contact the wall of the annular groove. With such a structure, the protrusion of the adjusting ring and the annular groove of the router base are engaged with each other by a ball bearing structure.

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a router 10 according to an embodiment of the present invention.
Indicates. The router 10 includes a motor housing 12 that houses a motor (not shown) therein. Electric power is supplied to the motor through the cord 14 and a switch (not shown). Further, this motor is provided with a rotation output shaft 16, and a collet 18 for attaching a cutting blade (not shown) is attached to the rotation output shaft 16.
The motor, the equipment for mounting the motor in the motor housing 12, the cutting blade collet 18, and the like are not directly related to the features of the present invention, and therefore further description will be omitted.

The motor housing 12 is supported by the base portion 20. The base 20 is provided with a pair of handles 22, which an operator can grasp to operate the router 10 along the surface of the workpiece. The motor housing 12 is supported by the base 20 so that the cutting blade attached thereto extends below the lower support surface 24 of the base 20. The cutting operation by the router 10 is performed by placing the lower support surface 24 on the upper surface of the workpiece. Therefore, the cutting depth of the router 10 is defined by the amount by which the cutting blade projects downward from the lower support surface 24. This cutting depth can be adjusted by moving the motor housing 12 relative to the base 20 in the longitudinal direction thereof. Regarding the method of this adjustment, the above-mentioned patent application 1992 No. 7
No. 8351 is described in detail.

The method of adjusting the cutting depth will be described below. As described in the patent application No. 784351 of 1992, the outer shape of the motor housing 12 is substantially cylindrical. The motor housing 12 comprises a first longitudinal region 26 having a substantially flat outer surface and a second longitudinal region having an outer peripheral surface threaded. On the other hand, a cylindrical hole 30 is formed inside the base 20. The flat longitudinal region 26 of the motor housing 12 is inserted into the cylindrical hole 30. A groove extending in the longitudinal direction is formed on the inner peripheral wall of the cylindrical hole 30, and the motor housing 12 is formed with a projection that fits in this groove. With such a structure, the motor housing 12 cannot rotate with respect to the base portion 20.

The present invention relates to a mechanism for adjusting the cutting depth of the router 10. As such a cutting depth adjusting mechanism, the router 10 is provided with an adjusting ring 32.
The adjusting ring is engaged with the outer peripheral thread 28 of the motor housing 12 and is also rotatably engaged with the base 20. As described above, since the rotation of the motor housing 12 is restricted with respect to the base portion 20, the motor housing 12 can be displaced in the longitudinal direction with respect to the base portion 20 by rotating the adjusting ring 32. As a result, the distance that the cutting blade projects downward from the lower support surface 24 can be changed. After changing the cutting blade protrusion amount in this way, the cutting depth can be maintained at a desired value by tightening and fixing the adjustment ring 32 to the motor housing 12 and the base portion 20.

The structure of the cutting depth adjusting mechanism will be described below.
It will be described in more detail. A screw thread 34 is formed on the inner peripheral surface of the adjusting ring 12, and the inner peripheral screw thread 34 engages with the outer peripheral screw thread 28 of the motor housing 12. Base 2
An annular groove 36 is formed at the upper end of 0. On the other hand, the adjusting ring 32 is formed with an inwardly extending inward projection or flange 38 which engages with the annular groove 36 of the base 20. Therefore, when the adjusting ring 32 is rotated, the adjusting ring itself does not move in the longitudinal direction, but the action of the pitch of the outer peripheral thread 28 and the inner peripheral thread 34 engaged with the outer peripheral thread 28 causes the motor housing 12 to move toward the base 20. On the other hand, it moves in the longitudinal direction. The operator rotates the adjusting ring 32 to a desired cutting depth and then fixes the adjusting ring to the motor housing 12 and the base 20 by the tightening mechanism 39 to fix the cutting ring to the desired cutting depth.

The adjustment ring 32 is preferably a half ring having a pivot point 40, as shown in detail in FIGS. Here, the half ring 32 is composed of two members having a substantially semicircular planar shape. Such a shape not only makes the adjustment ring 32 economical to form, but also allows the adjustment ring 32 to be easily attached to the router 10. The adjusting ring 32 is preferably made of a plastic material such that it has elasticity.

By the way, when the base 20 is made of metal, when the adjusting ring 32 is rotated with respect to the base 20, it is between the inner protrusion 38 of the adjusting ring 32 and the wall of the annular groove 36 of the base 20. Friction occurs. With such friction,
Not only does it make it difficult to rotate the adjustment ring 32 smoothly with respect to the base 20, but it also wears the inward projections 38 excessively and, in extreme cases, damages them before their life is reached. In consideration of such a situation, in the present invention, the inward projection 38 has a flange shape having a ball bearing structure. By adopting the ball bearing structure for the inner protrusion 38, the friction between the plastic and the metal is reduced, and the engagement between the inner protrusion 38 and the annular groove 36 is reduced.

The inner protrusion 38 of the above structure is shown in FIGS.
As shown in FIG. 3, the shape is not a flat flange shape having a constant width, but a shape in which a plurality of box-shaped portions project inwardly from each other at equal intervals. A ball is held in each box-shaped portion. More specifically, in each box-shaped portion, the ball is held so as to project outward from the opening formed in the box-shaped portion and contact the wall portion of the annular groove 36 of the base portion 20. Such a structure functions as a ball bearing structure with less friction. More specifically, in this embodiment, the inner protrusion 38 is formed with a total of six box-shaped portions 42, 44, 46, 48, 50, 52. Three of these six boxes (42, 44, 4
6) is formed on one semi-cylindrical portion of the adjusting ring 32 having a half ring structure, and the remaining three (48, 50, 5
2) is formed on the other semi-cylindrical part. As will be described later, the box-shaped portions 42 to 52 have a structure in which the held balls are alternately projected in directions opposite to the axial direction of the router 10. Therefore, the base 2
Both the upper side wall and the lower side wall forming the annular groove 36 of 0 can contact the ball.

A hollow portion or a pocket portion is formed inside each of the box-shaped portions 42 to 52. For example, in the box-shaped portion 44, as shown in FIG. 6, a hollow portion or a pocket portion 54 is formed. The cavity 54 is formed with a first opening 56 for communicating with the annular groove 36 of the base 20 and a second opening 58 for communicating with the outside of the adjusting ring 32. A ball 60 is held in the cavity or pocket 54, as shown in FIG. The ball 60 is held in a state in which a part thereof projects from the first opening 56. The sizes of the ball 60 and the openings 56 and 58 are such that the ball 60 can pass through the opening 58, but cannot pass through the opening 56. The pocket portion 54 is further provided with a holding means for holding the ball in the pocket portion 54. In the case of this example, the tab 62 extending in the pocket 54 at a position between the first opening 56 and the second opening 58 is the holding means. here,
The tab 62 has a side 64 opposite the first opening 56.
It has a slope extending obliquely from the second opening 58.
Therefore, the ball 60 inserted into the pocket 54 through the second opening 58 can move along the inclined surface 64 of the tab 62. The tab 62 also has a second opening 5
The ball inserted into the pocket 54 from 8 is prevented from returning to the outside from the second opening 58. Here, the tab 62 is formed of the same elastic material as the material of the adjusting ring 32, and above the tab 62, the elasticity of the tab is increased when the ball is inserted into the pocket portion 54. A notch 66 for forming is formed.
Therefore, the tab 62 can reliably prevent the ball inserted in the pocket portion from returning to the outside.

Of the six box-shaped protrusions 42 to 52, the protrusions 44 and 50 are located at the centers of the two semi-cylindrical portions of the adjusting ring 32, respectively. These protrusions 4
4 and 50 have a structure in which substantially the same structure is simply inverted in the router longitudinal axis direction. On the other hand, regarding the other on-the-box protrusions 42, 46, 48, 52, the above-mentioned on-the-box protrusions 44, 50 are formed because of restrictions on molding and the necessity of pulling out the manufactured adjustment ring in the linear direction from the molding die. Have a somewhat different structure. FIG. 7 shows one box-shaped protrusion 42 of these protrusions.

A cavity or a pocket 68 is formed inside the box-shaped protrusion 42.
8 is formed with a first opening 70 for communicating with the groove 36 of the base 20 and a second opening 72 for communicating with the outside of the adjusting ring 32. The pocket 68 has a position between the first and second openings 70 and 72,
A tab 74 having elasticity is formed. More specifically, the tab 74 has a first opening 7 in the pocket 68.
It is formed on the side opposite to 0. These box-shaped protrusions 4
2, 46, 48, and 52 are formed so as to extend in a direction having an angle with respect to the radial direction of the semicircular adjustment ring, and when the half adjustment ring is completely opened (see FIGS. In this state), the main axes of these pockets all extend in parallel. With this structure, the adjustment ring 32 can be pulled out straight from the molding die.

When the balls 60 are inserted into all of the six box-shaped projecting portions 42 to 52 having the above structure, these balls are projected in the vertical direction in order. More specifically, as is clear from FIGS. 4 and 5, the six box-shaped protrusions 4
2 to 52, the balls protrude downward in the protrusions 42, 46, and 50, and the protrusions 44, 48, and 52.
Then the ball projects upward. The ball protruding downward contacts the lower side wall of the annular groove 36 of the base 20, and the ball protruding upward contacts the upper side wall of the annular groove 36. Therefore, since an equal number (three in this case) of balls come into contact with the upper and lower side wall portions of the annular groove 36, the adjusting ring 32 is supported by the groove 36 in a well-balanced manner.

The present invention is not limited to the above-described embodiments, and various improvements or changes can be made within the scope of technical matters described in the claims.

[0022]

According to the router of the present invention, since the ball bearing structure is adopted for the protrusion of the adjusting ring, the protrusion of the adjusting ring and the groove of the router base can be engaged with each other with less friction. .. Therefore, even if the adjustment ring is formed by plastic molding and the router base is made of a metal material, the adjustment ring can be freely rotated and the protrusions of the adjustment ring are prevented from being excessively worn. You can

[Brief description of drawings]

FIG. 1 is a front view of a router of the present invention, a part of which is shown in cross section.

FIG. 2 is a top view showing a state where a half adjustment ring provided in the router of FIG. 1 is completely opened.

3 is a bottom view of the adjustment ring of FIG.

FIG. 4 is a front view showing the inner peripheral surface of the adjustment ring in the opened state in FIG.

FIG. 5 is a front view showing the outer peripheral surface of the adjustment ring in the opened state of FIG.

FIG. 6A is a view of the adjusting ring 6-6 shown in FIG.
It is an expanded sectional view which followed the line, (B) is a front view of the left side of (A).

7 (A) is a view showing the adjustment ring 7-7 shown in FIG.
It is an expanded sectional view which followed the line, (B) is a front view of the left side of (A).

[Explanation of symbols]

 10 router 20 base 36 annular groove 32 adjustment ring 38 inward projection 42, 44, 46, 48, 50, 52 box-shaped projection 54, 68 cavity 56, 70 first opening 58, 72 second opening 62, 74 tabs 60 balls

Claims (5)

[Claims] 1. A base having an annular groove on its outer circumference, and an adjusting ring for setting a cutting depth of a router, the protrusion having a projection for engaging with the annular groove of the base. Rotatably provided about a longitudinal axis of the router, wherein the adjusting ring is a plurality of cavities formed in the protrusion, each cavity being an annular groove of the base. A plurality of balls having a first opening communicating with the first opening and a second opening communicating with the outside of the adjustment ring, each ball being arranged in each cavity of the plurality of cavities; Each ball having a size smaller than the second opening of each cavity and larger than the first opening, and holding each of the plurality of balls in each corresponding cavity,
Accordingly, a holding means for causing a part of the ball to protrude from the first opening of each of the hollow portions and contacting this with one wall of the annular groove of the base, A router located between the first and second openings of the router. 2. An even number of said cavities are provided on said adjusting ring at equal intervals, and said first openings of said cavities are oriented in the first and second axial directions in sequence. The router according to claim 1, wherein the router is provided. 3. The holding means provided in each cavity of the plurality of cavities comprises an elastic tab extending to a position between the first and second openings in each cavity. Has a sloped surface that extends obliquely from the second opening on the side opposite to the first opening, so that the ball inserted into each of the cavities from the second opening can be attached to the sloped surface. 2. The router according to claim 1, wherein the router regulates the movement of the ball from the inside of each of the cavities to the outside although the ball is moved along the cavity. 4. The router according to claim 3, wherein a notch is formed on a side of the tab facing the first opening. 5. The adjusting ring is an integrally molded product made up of two substantially semi-cylindrical parts joined at a pivot point, and the plurality of cavity parts for pulling out the adjusting ring from its molding die. Router according to claim 1, characterized in that the main axes of all extend parallel to one another when the adjusting ring is fully open.