JP2010029953A - Bit adapter of hammer drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a hammer drill capable of performing a boring operation at a comparatively high location from a low location. <P>SOLUTION: A shank part 1b inserted in a hammer drill body D and an adapter body 1a having insertion means of a drill bit b are connected with each other via an inner cylinder 1c with a required length. An outer cylinder 3 having a length enough to be held by a hand is freely fitted with outside of the inner cylinder 1c. Also, an inside diameter of the outer cylinder 3 is made smaller than an outside diameter of the adapter body 1a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bit adapter for a hammer drill that is attached to a hammer drill body so that, for example, various bits having different diameters can be selectively used.

  A structure having an adapter main body with an insertion hole for inserting a drill bit on the other end (tip) side continuous with the shank portion is generally used on one end (base end) side (for example, Patent Document 1).

Japanese Utility Model Publication No. 4-5911

  The conventional example has a relatively short form because it has a configuration in which a shank portion protrudes from the rear end of the adapter main body. For example, when the hole is made in the ceiling for eaves bolts, the conventional example stays from the floor surface. When performing drilling work at a high place that is not, it is necessary to work using a scaffold such as a stepladder, and work at a place where the scaffold is unstable is dangerous.

  The present invention has been devised to provide a hammer drill capable of drilling a relatively high portion even from a low place in consideration of such a normal situation.

  The shank part to be inserted into the main body of the hammer drill and the adapter main body provided with means for inserting the drill bit are connected to each other via the inner cylinder of the required length, and the length that can be held by the hand on the outside of the inner cylinder This is a configuration in which an outer cylinder having a loose fit is loosely fitted.

  In addition, by adding a point in which the inner diameter of the outer cylinder is made smaller than the outer diameter of the adapter main body to this configuration, the outer cylinder is pressed against the adapter main body to give a propulsive force to the bit inserted into the main body, thereby performing a drilling operation. An efficient hammer drill can be obtained.

  According to the present invention, even if the inner cylinder is relatively long, the outer cylinder can be held by the hand, so that it is possible to provide a bit adapter that is inconvenient for the drilling operation. Therefore, it is possible to obtain a hammer drill that does not require a stepladder even when a relatively high portion is drilled by making the inner cylinder sufficiently long, which is preferable.

  FIG. 1 shows an embodiment of a bit adapter for a hammer drill according to the present invention. FIG. 1 shows a main body of a bit adapter A. The adapter main body 1 includes an adapter main body 1a having a means for inserting a drill bit b and a shank portion. 1b are connected to each other by an inner cylinder 1c (in the embodiment, they are screwed together, but other means such as welding may be used instead of this screwing means). 1, the operation cylinder 2 and the outer cylinder 3 of the insertion means are assembled so as to be movable along the axis so as to be engaged with the outside of the main body 1.

  The adapter main body 1a is provided with the above-mentioned insertion means by screwing a small-diameter portion 1a 'on the rear end side into the inner cylinder 1c and connecting it to the inner cylinder 1c.

  The insertion means includes an insertion hole 4 having an opening at the distal end surface and inserting the drill bit b in the shank portion, a lock pin 5 that is supported by the peripheral wall of the insertion hole 4, and the lock pin The operation cylinder 2 that presses 5 and engages with the recess of the shank portion of the bit b in the insertion hole 4, and is interposed between the operation cylinder 2 and the adapter main body 1 a. 5 and a coil spring 8 that holds the pressed state of 5, and when the drill bit b is inserted, the spring 8 is biased to maintain the engagement state of the operating pin 2 with the bit b in the insertion hole 4 of the lock pin 5. When the bit b is removed, the restriction of the lock pin 5 is released by the backward movement of the operation cylinder 2 against the bias of the coil spring 8 from the distal end side of the adapter main body 1a.

  The shank portion 1b is provided with a recessed portion on the rear side where a supporting means such as a chuck provided in the drill body D is engaged, and at the tip thereof is provided with a small-diameter portion 1b ′ similar to the adapter main body 1a. The adapter main body 1 is configured as described above with the adapter main body 1a by being screwed into the rear end of the inner cylinder 1c and connected to the inner cylinder 1c.

  The adapter main body 1 is constructed as described above by connecting the main body 1a and the shank 1b with a long inner cylinder 1c (made of steel pipe), and is attached to the hammer drill main body D by the shank 1b. Extending the distance between the drill bit b attached to 1a and applying it as an extension rod for a hammer drill, so it is possible to work from the floor surface, such as the ceiling surface, which has been impossible until now using a stepladder. In the embodiment, the inner cylinder 1c has a length of 1155 mm (the length of the drill bit b is 1155 mm longer than that of a normal bit adapter).

  The outer cylinder (made of steel pipe) 3 is mounted on the inner cylinder 1c or the adapter body 1 so as to be rotatable outside the inner cylinder 1c with the same length as the inner cylinder 1c. It is smaller than the outer diameter of the portion 1b (excluding the small diameter portions 1a ′ and 1b ′) and is locked to the step portions 12 and 12 ′ formed by providing the main diameter portion 1a and the shank portion 1b with the small diameter portions 1a ′ and 1b ′. Thus, the front and rear movements are restricted, and the outer cylinder 3 is pressed and locked to the step portion 12 to indirectly press the bit b inserted into the main body portion 1a and to be pressed from behind. b obtains a propulsive force and efficiently performs the drilling operation.

  The bit adapter A of the embodiment is assembled to the hammer drill body 1 at the shank portion 1b, and the drill bit b is inserted into the adapter main body 1a and used, and the outer cylinder 3 is held by hand as necessary. The drill bit b attached to the main body 1 is pressed against the drilled body by pressing the outer cylinder 3.

  Note that making the inner diameter of the outer cylinder 3 smaller (narrower) than the outer diameter of the adapter main body 1a means that the outer cylinder 3 cannot move in contact with the adapter main body 1a. This includes a case where a protruding portion is provided to receive pressure from the outer cylinder 3.

  In addition, the outer cylinder 3 can be perforated at the position where the bit b and the drill body D are separated from the operator corresponding to the length of the outer cylinder 3, but if it is too long, the weight increases (the inner cylinder 1c is Since the cylinder is a result of weight reduction), it should be noted that the length does not need to be the same length as the inner cylinder and can be held at least by hand. Should be.

Sectional drawing of a bit adapter.

Explanation of symbols

1a Adapter main body 1b Shank 1c Inner cylinder 3 Outer cylinder

Claims (2)

  The shank part to be inserted into the main body of the hammer drill and the adapter main body provided with means for inserting the drill bit are connected to each other via the inner cylinder of the required length, and the length that can be held by the hand on the outside of the inner cylinder A bit adapter for hammer drills with loosely fitted outer cylinders.   The bit adapter for a hammer drill according to claim 1, wherein the inner diameter of the outer cylinder is smaller than the outer diameter of the adapter main body.

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