JPH05278001A - Blade attachingt and detaching device of cutter - Google Patents

Abstract

PURPOSE:To easily and rapidly attach and detach a blade by one-action operation without using an exclusive tool and to certainly hold the blade so as to prevent the detachment thereof. CONSTITUTION:A terrace like engaging part 15 with which the protruding engaging part 14 of a blade 6 is engaged is formed to the inside of the leading end part of a plunger 3 and the press member 16 pressing the upper end of the blade 6 is provided in the plunger 6 above the engaging part 15 and the cam engaging pin 17 engaged with the fixing cam member 7 arranged to the outer periphery of the plunger 3 so as to protrude from the side wall of the plunger 3 is formed to the outer wall of the plunger 3. The press member 16 is moved up and down through a cam part 18 by the operation of the fixing cam member 7 and a blade holder 5 enabling the attachment and detachment of the blade 6 is constituted and the blade is attached and detached by the one-action operation due to the slight revolution of the fixing cam member 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting machine such as a jigsaw or a reciprocating saw, and more particularly to a blade attaching / detaching device capable of attaching / detaching a blade by one-touch operation. Hereinafter, the cutting machine will be described as a jigsaw.

[0002]

2. Description of the Related Art FIG. 10 shows a prior art. A gear provided in the cover 2 by a motor in an outer frame (not shown),
The blade 6 is attached to the blade holder 5 at the lower end of the plunger 3 which is reciprocally moved through a power transmission means such as a crank mechanism by a set screw 40, and a special tool such as a hexagon wrench 41 is used to attach and detach the blade 6. I was going.

[0003]

Since the dedicated tool such as the hexagonal wrench 41 is used for attaching and detaching the blade 6, there is a problem that the blade 6 cannot be replaced when the tool 41 is lost. It was If the set screw 40 that fastens the blade 6 is not strongly tightened, it will be loosened by vibration during cutting work, and in the worst case, the blade 6
There was a risk that the dangerous situation of falling out would occur.
The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to enable the blade to be quickly and easily attached / detached by one-touch operation without using a dedicated tool, and to securely hold the blade even by vibration during cutting work. And not to drop it.

[0004]

In order to achieve the above object, in the blade attaching / detaching device of the present invention, a terrace-like engaging portion with which the protruding engaging portion of the blade engages is formed inside the tip portion of the plunger. Then, a pressing member for pressing the upper end of the blade is installed above this, and a cam engaging portion that protrudes from the side wall of the plunger and engages with the fixing cam member arranged on the outer periphery of the plunger is formed on the outer wall of the pressing member. The pressing member moves up and down through the cam portion by the operation of the fixing cam member, and constitutes a blade holder portion that enables the attachment / detachment of the blade. One-touch operation by slightly rotating the fixing cam member. The blade is attached and detached.

[0005]

In the cutting machine constructed as described above, the engaging portion in the plunger which moves up and down and the fixing cam member mounted on the outer periphery of the tip of the plunger are appropriately moved up and down. The pressing member holds the blade directly and firmly by one-touch operation. If the cam shape formed on the fixing cam member is formed of continuous two-step steep slopes and gentle slopes, the blade fixation that is difficult to loosen is realized by the action of the gently sloped cams formed in the latter half. Furthermore, the loosening prevention mechanism arranged adjacent to the fixing cam member reliably prevents the fixing cam member from loosening, so that the pressing member that holds the blade can maintain the pressing force as it is, and the vigorous up and down movement of the plunger is prevented. It will not loosen due to movement or vibration during cutting work, and blades will never fall off.

[0006]

The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 shows a main part of a cutting machine equipped with a blade attaching / detaching device of the present invention, in which a motor inside an outer frame 1 stores a plunger 3 through a power transmission means such as a gear and a crank mechanism housed inside a gear cover 2. Is supported by the metal 4 and reciprocates up and down. A blade 6 is inserted into a blade holder 5 formed integrally with the lower end of the plunger 3 and attached by a fixing cam member 7 described later, and a loosening prevention mechanism 8 is engaged with the cam member 7 to operate. The cam member 7 is securely prevented from loosening. The base 9 serves as a guide surface that slides on a cutting material (not shown).

FIG. 2 shows the details of the blade holder 5. At the tip of the plunger 3, two split grooves 11, 11 are provided in the axial direction, and at the inner circumference of the tip, a pair of overhang locking portions 14 formed near the upper end of the blade 6,
A pair of terrace-shaped locking portions 15, 15 that engage with 14 are formed. Reference numeral 16 is a pressing member, and a pair of engaging pins 17, 17 formed on the outer periphery of the pressing member are the split grooves 1 of the plunger 3.
It is slidably fitted into the first and the first members 11 and inserted into the plunger 3. Reference numeral 18 denotes a cam portion of the cam member 7, which is a pressing member 16
The pressing member 16 is configured to move up and down in the plunger 3 by being connected to the engaging pins 17 of and rotating the cam member 7 on the outer circumference of the plunger 3. As shown in FIG. 3, the cam portion 18 is formed with a continuous two-stage inclined surface. The steep inclined surface 18A having a large amount of movement in the initial stage of the turning operation and the gently inclined surface 18B in the latter half thereof have a cam shape that is hard to loosen. As a result, the pressing member 16 completes its movement with a slight turning operation. A scoring knurl 19 or the like is engraved on the outer periphery of the cam member 7 for easy tightening.
Reference numeral 20 denotes a stop washer that prevents the fixing cam member 7 from falling off. The rotation ratchet 22 of the loosening prevention mechanism 8 is fixed to the cam member 7 and operates integrally. Reference numeral 23 is a fixed ratchet, which is normally biased by a spring 25 between the flange portion 24 of the plunger 3 and meshes with the rotary ratchet 22 to restrict the retreat of the cam member 7. Further, the fixed ratchet 23 has a locking portion 26 on its upper portion, which engages with the collar portion 24.
Ratchet 2
Release the mutual restrictions on February 23rd.

4 to 7 show the pressing member 16, and a pair of engaging pins 17 projecting to the outer periphery of the pressing member 16 are fitted in the split grooves 11, 11 of the plunger 3 so as to be vertically movable as described above. Then, the cam member 7 is engaged with the cam member 7, and the pressing member 16 moves up and down in the plunger 3 by the turning operation of the cam member 7. Reference numeral 27 denotes a groove portion for accommodating the upper end portion 28 of the blade 6 and pressing and fixing or releasing the blade 6 at the bottom portion 29 by vertically moving the pressing member 16. The groove portion 27 is formed so that the blade 6 can rotate at least ⅛, and when the blade 6 is rotated, the projecting locking portion 14 moves and rides on the terrace-shaped locking portion 15. There is.

8 and 9 show a fixed ratchet 23, which has ratchet teeth 30 on one end surface and an engaging portion 26 which engages with an engaging groove 31 formed in the collar portion 24 on the other end surface. ing. The engagement portion 26 causes the fixed ratchet 23 to properly move up and down at a fixed position to regulate the operation of the rotating ratchet 22. Reference numeral 32 denotes a ratchet releasing locking groove, which locks with the engaging groove 31 formed in the collar portion 24, and is used to rotate the ratchet 22.
The fixed ratchet 23 and the fixed ratchet 23 are disengaged from each other, and the operation restriction of the cam member 7 can be released. The ratchet release locking groove 32 is directionally shaped so that the fixed ratchet 23 automatically returns to mesh with the rotating ratchet 22 in accordance with the fixing operation of the cam member 7. Three
Reference numeral 3 denotes an operation wing for operating the fixed ratchet 23.

Next, the operation of the present invention will be described. In FIG. 2, the blade 6 is inserted from the tip of the plunger 3 into the split groove 11, and it is confirmed that the overhanging locking portion 14 is inserted into the blade holder 5. The locking portion 14 can ride on the terrace-shaped locking portion 15 of the plunger 3 to be locked. When the cam member 7 is rotated from this state, the pressing member 16 moves the cam portion 18
Is pushed down to the blade 6 side through the pin 17 engaged with the blade 6, and the upper end 28 of the blade 6 is moved to the bottom 29 of the pressing member 16.
When the blade 6 is abutted against and further rotated, the blade 6 is held in the plunger 3 by the overhanging locking portion 14 and the upper end portion 28. This gripping operation is devised so that it can be completed with a slight rotation by the two gradually and suddenly-formed cam surfaces 18A and 18B formed on the cam member 7, and the gently inclined surface formed on the latter half of the cam portion 18 is formed. 18B is a pin 17 of the pressing member 16.
The cam part 1 works so that the locking with
8 does not easily loosen. The rotation ratchet 22 interlocks with the movement of the cam member 7 to engage with the fixed ratchet 23 pressed by the spring 26 and slides only in the tightening direction so that the held state can be maintained more reliably, and the cam member 7 rotates in the loosening direction. Regulate.

When removing the blade 6, the fixed ratchet 23 is pulled upward against the spring 25,
The ratchet release locking groove 32 is locked to the locking portion 31 formed on the collar portion 24. In this state, the cam member 7 can freely rotate, and when it is rotated in the loosening direction, the holding state between the pressing member 16 and the plunger 3 is released, and the blade 6 is rotated ⅛ and locked in a terrace. It may be removed from the portion 15 and pulled out.

[0012]

As described above, according to the present invention, it is possible to provide a one-touch operation blade attaching / detaching device which can easily attach / detach the blade by a slight rotation of the cam member. In addition, since the blade is prevented from loosening due to vibration during cutting, the blade can be prevented from falling off.

[Brief description of drawings]

FIG. 1 is a partially longitudinal side view showing an embodiment of a blade attaching / detaching device of the present invention.

FIG. 2 is an enlarged vertical sectional side view showing details of the blade holder portion of FIG.

FIG. 3 is a vertical sectional side view of a fixing cam member.

FIG. 4 is a front view of a pressing member.

FIG. 5 is a side view of FIG.

FIG. 6 is a bottom view of FIG.

7 is a vertical front view of FIG.

FIG. 8 is a vertical sectional side view of a fixed ratchet.

FIG. 9 is a bottom view of FIG.

FIG. 10 is a perspective view showing an example of a conventional jigsaw.

[Explanation of Codes] 3 is a plunger, 5 is a blade holder, 6 is a blade,
7 is a fixing cam member, 8 is a loosening prevention mechanism, 14 is an overhanging locking portion, 15 is a terrace-shaped locking portion, 16 is a pressing member,
Reference numeral 17 is a cam engagement pin, 18 is a cam portion, 22 is a rotating ratchet, 23 is a fixed ratchet, and 26 is a locking portion.

Claims (6)

[Claims] 1. A blade attaching / detaching device for attaching a blade to a tip of a plunger reciprocated by a motor and attaching / detaching a blade of a cutting machine for cutting by the reciprocating movement of the blade, wherein an inner peripheral tip of the plunger is provided. , Forming a terrace-shaped locking portion with which the overhanging locking portion of the blade engages by slightly rotating the blade, and installing a pressing member for pressing the rear end of the blade above the inside of the plunger and of the pressing member. A blade holder portion that engages a fixing cam member with a pair of cam engagement pins that are formed on the outer periphery and project from the side wall of the plunger, and appropriately move the pressing member up and down to allow the blade to be attached and detached. A blade attaching / detaching device for a cutting machine, which is characterized in that 2. The cam shape of the fixing cam member is formed in two stages, a steep slope shape in which the first half can have a large movement distance and a gentle slope shape in which the latter half is hard to loosen, and also has a cam member loosening prevention mechanism. The blade attaching / detaching device for a cutting machine according to claim 1, wherein 3. The blade attaching / detaching device for a cutting machine according to claim 1, further comprising a cam member loosening prevention mechanism disposed adjacent to said fixing cam member for restricting a loosening direction thereof. 4. The ratchet mechanism for preventing loosening of the cam member is composed of a rotating ratchet integrally formed on the fixing cam member and a fixed ratchet integrally formed on the plunger. The blade attaching / detaching device of the cutting machine according to claim 3. 5. The blade attaching / detaching device of a cutting machine according to claim 4, wherein the fixed ratchet is formed with a locking portion for maintaining the operation release state of the ratchet mechanism. 6. The locking portion is formed so as to have a directivity so that the ratchet mechanism can be normally operated by naturally returning along with the rotating operation of the rotating ratchet when the blade is fixed. The blade attaching / detaching device of the cutting machine according to claim 5.