CN1069250C - Saw for caving hole - Google Patents

Abstract

The invention discloses a portable jigsaw (10) with a lifting rod (18). The lifting rod has a saw blade (23) clamping device (20), which has a bottom with radially inwardly protruding clips. The clamping sleeve (21) of the ring (46), when in the clamping position, the collar axially supports and clamps the lugs (49, 50) of the clamping end (22) of the saw blade, and also sets the clamping sleeve The operating part of the cylinder is rotated to the release position, the clamping device has the function of holding the clamping sleeve in the saw blade release position relative to the lifting rod and releasing the clamping sleeve again by inserting the saw blade into the clamping device The brakes (53';54') and thus the operating part (27) only drive the clamping only to rotate the clamping sleeve to the release position, not to bring it back to its clamping position.

Description

jigsaw

The invention relates to a portable jigsaw mechanism, which has a lifting rod, which can guide and move between its upper and lower bearings, and has a clamping device for clamping the saw blade at its lower end, and the clamping device has A clamping sleeve, which has a radially inwardly protruding collar at its free bottom end, which bears axially in the clamping position and thereby clamps the lug at the clamping end of the saw blade. The ear is also provided with an operating part fixed on the casing for turning the clamping sleeve to the release position.

German patent application laid-open specification 4138986 discloses a jigsaw of the above-mentioned type. In such a jigsaw, the saw blade can be replaced in an advantageous manner: a rotatable switching sleeve fixed to the housing is mounted on the gear box, and the switching sleeve can be swung by hand around the sleeve shaft from the outside. The swinging motion of the switch sleeve is transmitted to the clamping sleeve of the device through the transmission block to clamp the saw blade. There is a handle on the switch sleeve, and in order to remove the saw blade, the handle must be swung by hand about the shaft of the lifting rod. The switch sleeve is rotatably fixed in the gear and the box through multiple supporting points. Due to the presence of sawdust, the aforementioned bearing points are subject to considerable wear. Furthermore, the switch sleeve must be held in the release position by hand. Therefore, saw blade replacement is cumbersome and time-consuming.

The jigsaw according to the invention employs the following solution: the clamping device has a mechanism for holding the clamping sleeve in the blade-release position relative to the lifting rod and releasing the clamping sleeve again by inserting the saw blade into the clamping device. The moving part, so that the operating part moves with the clamping sleeve from the clamping position to the release position in a synchronous meshing manner in only one direction of movement, that is to say, the operating part disengages from the clamping sleeve from the release position and automatically Return to its initial position. Compared with the previous prior art, the jigsaw with the above structure has the following advantages: because its direction of movement (preferably from top to bottom) is very convenient for the operator, the saw blade can be replaced quickly and easily; The switch sleeve only needs to be operated in one direction (that is, the direction of unclamping the saw blade), but not in the direction of clamping the saw blade. Furthermore, it is not necessary to hold the switch sleeve by hand when removing the saw blade and inserting a new saw blade, but it can be released after the switch sleeve has reached the release position, where the switch sleeve returns to its original position. Location.

As another improvement of the present invention, the rotating operating part can adopt a slide rod, which drives a radial transmission stop of the clamping sleeve on its moving track, and thus makes the clamping sleeve rotate .

Another improvement of the present invention is that the slide bar is connected to the clamping sleeve via a traction mechanism, in particular a traction rope.

Another improvement of the present invention lies in that one end of the traction mechanism formed by the traction rope is wound on the clamping sleeve, and the other end is fixed on the slide bar.

The further improvement of the present invention lies in that the slide bar is supported on the housing in a manner that can move parallel to the lifting rod, and a projection is embedded into an adjustment mechanism that is arranged on the side of the housing and can rotate around the clamping sleeve. (especially a switch sleeve), so that the movement of the slide bar rotates the adjustment mechanism and drives the clamping sleeve.

The further improvement of the present invention lies in that the adjusting mechanism is arranged on the ring-shaped guide rail in a manner of swinging back and forth around the clamping sleeve.

The further improvement of the present invention is that the slide bar is formed by a rack. The teeth of the toothed rack mesh with the teeth of the clamping sleeve.

A further improvement of the invention is that the adjusting mechanism formed by the toothed rack meshes with its teeth with a gear wheel rotatably mounted on the housing, which is coupled to a slide bar with teeth.

A further development of the invention consists in that the gear co-operates in the form of a bevel gear with further teeth on the slide bar which form a spur gear.

A further improvement of the present invention is that the operating part is formed by a rocker, the free end of which is in contact with the radial circumference of the clamping sleeve, in particular colliding with the radial transmission stop of the clamping sleeve.

Embodiments of the present invention will be described in detail below according to the accompanying drawings.

Shown in Fig. 1 is the embodiment of jigsaw of the present invention;

Fig. 2 is a saw blade clamping device;

Fig. 3 is the bottom view of Fig. 2;

4 and 5 are perspective and top views of an embodiment of an operating device for rotating the clamping sleeve;

Figures 6 and 7 are perspective and top views of another embodiment of the invention using a rocker to rotate the clamping sleeve;

Fig. 8 and 9 are the regulating mechanism that is constituted by the traction rope and rotates the clamping sleeve;

Figures 10, 11 and 12 are vertically operable switch sleeves;

Fig. 13 is the regulating mechanism operated with rack;

Fig. 14 is the adjustment mechanism operated with a straight slide bar;

Figure 15 is an adjustment mechanism operated by gear transmission.

The jigsaw 10 shown in FIG. 1 includes a motor housing 12 flanged to a gearbox 14 . The motor housing 12 and the gear box 14 are installed on the bottom plate 16 together.

As far as the viewing direction is concerned, a lifting rod 18 that can move axially along its upper and lower bearings (not shown in the figure) in the gear box 14 extends downwards from the gear box 14. The lifting rod 18 has at its lower end a clamping device 20 with a clamping sleeve 21 for clamping and centering the saw blade clamping end 22 of the saw blade 23 .

The saw blade 23 passes axially through a recess 25 in the base plate 16 . Mounted on the side of the gearbox 14 is a double-arm lever 27 consisting of two arms arranged at right angles to each other, one of which is a button 28 and the other a push rod 29 . Both of the above-mentioned arms can swing around the same swing axis 30 . The length of the push rod 29 is longer than the possible stroke of the elevating rod 18, and when it swings, it pushes a drive stop 21' protruding radially outward from the periphery of the clamping sleeve 21.

When the button 28 is pushed downwards in terms of viewing direction, the push rod 29 moves to the vicinity of the clamping sleeve 21 and drives the drive stop 21' there. In this way, the pivoting movement of the push rod 29 is converted into a rotational movement of the clamping sleeve 21 . At the end of the rotation, the clamping sleeve 21 releases the clamping end 22 of the saw blade 23 so that the saw blade can be removed axially.

FIG. 2 shows a lifting rod 18 with a saw blade 23 clamping device 20 . A stepped piston type centering sleeve 52 has an annular slope 54. When the centering sleeve 52 moves axially, by means of this annular slope, the radial holes 68, 69 located in the lower area of the lifting rod 18 can be The positioning balls 53', 54' move radially.

The lifting rod 18 forms a flange-shaped external thread section in a stepped manner radially outward. The profile of the lifting rod 18 then steps radially inwards, and from there extends with a smaller outer diameter, essentially straight and open, to the bottom edge 32 .

The lifting rod 18 has an axial central stepped hole 27 inside, and the hole is a tubular structure at the bottom of the lifting rod 18 . The central stepped hole 27 terminates in a tapered hole 33 .

The clamping sleeve 21 is arranged on an externally threaded section 26 of the lifting rod 18 with threaded engagement. In its lower region, the clamping sleeve 21 gradually merges radially inwards into a collar 46 , the inner contour of which is formed by a through hole 48 and a radial groove 47 . The clamping sleeve 21 has a locking groove 55 , 56 on its inner periphery adjacent to the radial holes 68 , 69 of the lifting rod 18 .

The lifting rod 18 and the clamping sleeve 21 are connected to each other with prestress by means of a torsion spring 42 , where the spring bottom 43 engages in the radial recess 43 ′ of the lifting rod 18 and the spring top 44 engages in the clamping sleeve 21 . In the radial notch 44'. Due to the corresponding prestressing force of the torsion spring 42 , the clamping sleeve 21 is held in the axially upwardly pushed detent position relative to the external threaded section 26 .

On the positive top end 57 of the centering sleeve 52 is supported a compression spring 58 which attempts to press the centering sleeve 52 downwardly relative to the lifting rod 18 . Positioning balls 53', 54' are placed in the radial space between the cylindrical area 51 of the centering sleeve 52 and the stepped hole 27. These balls are located in radial holes 68 , 69 in the walls of the lifting rod 18 .

The narrow side of the upper area of the saw blade clamping end 22 is centered in the tapered hole 33 in the upper area of the lifting rod 18 . The top ends of the blade lugs 49 , 50 are centered on the V-shaped groove 60 of the lower end 59 of the centering sleeve 52 . The bottom ends of the saw blade lugs 49, 50 (only one lug 49 is visible when looking at the saw blade from the side) bear on the inner side 46' of the collar 46 of the clamping sleeve 21. The inner side 46' of the collar ensures that the saw blade 23 is held within the device 20 and will not come out or fall downwards. For rotational operation, the clamping sleeve 21 has a radial drive stop 21'.

Figure 3 is a bottom view of the device 20, showing the clamping sleeve 21 with the through-hole structure 48, the radial groove 47 and the collar 46 and the radial drive stop 21'.

The mode of operation of the device 20 is as follows: to release the saw blade 23, the clamping sleeve 21 is rotated relative to the threaded section 26, and at the same time the clamping sleeve is moved axially downward due to the screw connection with the external thread 26. In a predetermined braking position, the clamping sleeve 21 cannot continue to rotate; in this position, the engaging grooves 55 , 56 are flush with the radial holes 68 , 69 .

Along with the axial movement of the clamping sleeve 21, the saw blade 23 moves axially downward. In addition, due to the action of the compression spring 58, the centering sleeve 52 moves with the saw blade, and the centering V-shaped groove 60 bears on the blade lugs 49,50. At this time, the inclined surfaces 53, 54 are in contact with the positioning balls 53', 54', so that the balls are pushed radially outwards. Simultaneously, the inclined surfaces 53,54 and positioning balls 53',54' enter the engaging grooves 55,56. This position of the positioning balls 53', 54' is ensured by the centering sleeve 52 due to the action of the compression spring 58. Due to the action of the positioning balls 53', 54', the clamping sleeve 21 is stuck in its rotational position. Clamping sleeve 21 can not return to its initial position, and the opening position of its radial slot 47 is flush with the plane of saw blade 23 at this moment, can take out saw blade 23 downwards very easily or under the preset force action of compression spring 58 The saw blade 23 is ejected.

To mount the saw blade 23 , the clamping end 24 of the saw blade 23 is inserted axially upwards into the through hole 48 and the radial groove 47 of the clamping sleeve 21 . When the top ends of the lugs 49 , 50 of the saw blade come into contact with the centering V-shaped grooves 60 , 61 , the centering sleeve 52 and the saw blade 23 move axially upwards pushing the compression spring 58 . Inclined surfaces 53,54 release positioning balls 53', 54'. Due to the action of the torsion spring 42 and the resulting rotation of the clamping sleeve 21, the positioning balls 53', 54' are returned from the locking grooves 55, 56 to the space between the centering sleeve 52 and the central stepped hole 27 and radial holes 68,69. At this moment, the clamping sleeve 21 is loosened and can continue to rotate, and at the same time move axially upwards. Thus, the radial groove 47 is rotated relative to the lugs 49, 50 of the saw blade so that the collar 46 and inner side 46' axially contact the bottom ends of the lugs 49, 50 of the saw blade and continue to move axially upward until the blade The clamping end 22 is located centrally within the tapered bore 23 . Thus, the saw blade 23 is centered and clamped and cannot fall out of the device 20 .

FIG. 4 shows a clamping sleeve 121 that is rotatable about the lifting rod axis 119 and functions like the embodiment of FIG. 2 . The clamping sleeve 121 has a radial transmission block 132 driven by the slide rod 129 and rotates around the shaft 119 together with the clamping sleeve 21 . For this reason, the slide bar 129 is fixed in the upper and lower sliding guide rails 180, 182 in a movable manner against the action of the return spring 184 constituted by the compression spring. The sliding guide rails 180, 182 and the return spring 184 composed of compression springs and/or extension springs are immovably fixed in the unshown gear box.

FIG. 5 is a top view of FIG. 4 , in which the clamping sleeve 121 , the sliding rod 129 , the transmission stop 132 and the return spring 184 composed of a compression spring can be clearly seen. The sliding track of the sliding bar 129 is schematically indicated by a dotted line.

Shown in Fig. 6 is a clamping sleeve 221, and elevating rod shaft 219, transmission block 332 and return spring 284, and this clamping sleeve 221 passes through a rib-shaped double-arm lever 227 that can swing around pendulum 230 and resets. The spring 284 is connected, and one arm of the double arm is the button 228 and the other is the push rod 229 . The support 230' of the balance shaft 230 shown schematically is fixed on the gear case 214 shown symbolically in the figure. The operating arrow 185 indicates the direction of action of the operator's finger. Movement arrow 287 indicates the pivoting direction of clamping sleeve 221 and push rod 229 .

FIG. 7 shows a clamping sleeve 221 in a plan view, wherein the drive stop 232 in the initial position is indicated by a dotted line. The transmission block 232 when driven to the release position by the operating lever 227 is represented by a solid line. Furthermore, the button 228 , the push rod 229 and the pivot 230 are clearly visible, as well as the symbolically indicated mounting of the pivot 230 on the gearbox 214 .

Fig. 8 shows a clamping sleeve 321, which can swing around the lifting rod shaft 319 together with the transmission block 332, so as to loosen or clamp the saw blade not shown in the figure.

The upper rope 325 connected with the transmission block 332 and guided by the rollers 330, 330' rotatably fixed on the casing is used as an operating mechanism. The pull cord 327 is moved by a slider-type button 329 guided in the wall of the housing 314 .

FIG. 9 is a side view of the clamping sleeve 321, wherein the highest stroke position of the clamping sleeve is indicated by a solid line, and its lowest stroke position is indicated by a dotted line. It can be clearly seen from this that the traction rope 327 does not need to be hinged due to its bendability to keep up with the movement of the clamping sleeve 321 .

A return spring for the pull cord 327 may be provided, but is not absolutely necessary in the above case. The function of the return spring can be realized by the return torsion spring (corresponding torsion spring 42 in FIG. 2 ) of the clamping sleeve 321 . But by means of a separate return spring, the longitudinal balance of the traction cord 327 corresponding to the lifting position of the clamping sleeve 321 can be easily achieved, so that the operation of the traction cord is satisfactory due to its small seamwise gap.

FIG. 10 shows a jigsaw 410 with a gearbox 414 .

As far as the viewing direction is concerned, a lifting rod 418 that can move axially along the upper and lower bearings (not shown in the figure) in the gear box 414 extends downward from the gear box 414 . The lifting rod 418 has at its lower end a clamping device 420 with a clamping sleeve 421 for clamping and centering a saw blade 423 .

As indicated by operating arrow 485, a vertically movable slide bar 429 can move vertically up and down in slide rail 480 on gear box 414 of jigsaw 410. Slide bar 429 has a projection 430, and this projection is embedded in the chute 488 of the switch sleeve 489 that is arranged on the gear case 414, and swings around lift rod shaft 419, and is blocked by this groove. This switch sleeve 489 links to each other with gear case 414 via a torsion spring part not shown, and with its transmission block 490 that stretches out radially inwards, butt against the clamping sleeve 421 of clamping saw blade 423 The transmission gear port 423 protrudes radially outward.

FIG. 11 shows a cross-sectional view of the clamping device 420 of the saw blade 423 in FIG. 10 along the direction of arrow A-A. Wherein can clearly see the lug part 430 of clamping sleeve 421, its transmission block 432, elevating lever shaft 419, slide bar 429 (sliding bar 429 and slide guide rail 480 are not drawn), switch sleeve 489 and its Transmission block 490.

FIG. 12 is a side view of the switch sleeve 489 with a slanted slot 488 for fitting into the projection 430 .

When the slide bar 429 moves downwards according to the operation arrow direction 485, the switch sleeve 489 moves leftward according to the movement arrow 486 in the viewing direction. The transmission block 490 of the switch sleeve 489 is in contact with the transmission block 423 of the clamping sleeve 421 to drive the clamping cylinder to move by pressing the moving arrow 486 . Thus, the clamping sleeve 421 is rotated to the release position in which the saw blade 423 is released. If the slide bar 429 is released, the switch sleeve 489 returns to the initial position against the direction of the movement arrow 486 under the action of the tension spring 484 , and the slide bar 429 moves upward through the protrusion 430 .

FIG. 13 shows a schematic bottom or top view of the clamping sleeve 521 with a radial drive stop 532 . The protrusion 530 on the adjustment mechanism 589 that can swing around the lifting rod shaft 519 on the sliding guide rail 581 is supported on the transmission block 532 . The adjustment mechanism 589 has positive teeth 592 on the side facing away from the clamping sleeve 521 . Engaging with this is a rack-shaped straight slide 529 counter-engaging with teeth 594 (Gegenverzahnung), which can be actuated manually by pressing the button 528 . The slide bar 529 is movable axially in slide guides 580 , 582 as indicated by arrow 585 .

When the slide bar 529 moves along the direction of the operation arrow 585 , the adjustment mechanism 589 rotates around the lift shaft 519 . In addition, the protrusion 530 drives the radial transmission block 532 and the clamping sleeve 521 to rotate to the saw blade release position.

After the slide bar 529 is released, the return spring 58 makes the adjusting mechanism 589 bring the slide bar 529 back to its initial position. The drive dog 532 and the clamping sleeve 521 remain in their rotational position until the insertion of the saw blade releases the brake mechanism shown in FIG. 2 . Thereafter, the clamping sleeve 521 returns to its clamped position.

FIG. 14 is a top view of another clamping sleeve 621 that is rotatable around the lifting rod shaft 619 and has a radial drive stop 632 . The protrusion 630 of the adjustment mechanism 689 is arranged opposite to the above-mentioned transmission block 632 . The adjustment mechanism can guide and move along the sliding guide rail 681 . The drive projection 696 of the straight slide bar 629 with the button 628 is inserted into the adjustment mechanism 689 . The straight sliding rod can move axially in the fixed sliding guide rails 680, 682 of the gear box not shown in the figure.

The return spring 684 is supported between the end of the slide bar 629 and the support fixing part of the gear box not shown in the figure. When the straight slide bar 629 moves axially, its driving lug 696 on the straight track drives the adjusting mechanism 689 on the curved track. The barrel 629 is moved to the release position. When the button 628 is released, the return spring 684 makes the slide bar 629 return to the initial position. By actuating the lug 696, the adjustment mechanism 689 is brought back to its original position.

Shown in FIG. 15 is a clamping sleeve 721 with a radial transmission block 732 that can rotate and move around the lifting rod shaft 719 . The transmission block 732 rests on the flange 730 of the adjustment mechanism 789 which is movably located in the curved slide rail 781 . The adjustment mechanism 789 forms a rack on the side facing the viewer. The teeth 789' of the rack mesh with the bevel gear 798. This bevel gear and a spur gear 798' are connected together in a manner of synchronous rotation around the same rotating shaft, and the rotating shaft of the bevel gear 798 is fixedly connected with a gear box not shown in the figure. The teeth of the spur gears mesh with the teeth 729' of the toothed rack which moves axially in slide rails 780,782 and acts as slide bar 729. The slide bar 729 has a button 728 . In contrast, a return spring 784 is supported at the free end of the sliding rod 729 , the other end of which is supported at the schematically indicated gear box 714 .

When the slide bar 729 moves against the direction of action of the return spring 784, the bevel gear 798 and the spur gear rotate around the fixed shaft together. At the same time, the teeth of the bevel gear drive the adjustment mechanism to move along the sliding guide rail 781 . Draw the convex rib 730, and turn the transmission block 732 and the clamping sleeve 721 together to the saw blade release position.

When the slide bar 729 is released, the slide bar returns to the initial position under the action of the return spring 784 . At the same time, the slide bar drives the bevel gear 798 to rotate. By said turning, the adjustment mechanism 789 also returns to its initial position. For the gear ratio of the spur gear 798' to the bevel gear 798, a particularly favorable transmission or reduction ratio of the clamping sleeve 721 can be selected.

In another not described embodiment of the invention, the clamping sleeve has an inclined surface, which is arranged in the track of movement of the slider moved parallel to the lifting rod driven by the slider, which moves to push the slider When, the clamping sleeve is driven to rotate through the slope.

In all embodiments, it can be seen that the clamping sleeve moves up and down with the lifting rod, whereby there are a number of stop positions in which the clamping sleeve must be able to come into contact with the actuating part.

Furthermore, it should be noted that the clamping sleeve can have different rotational positions depending on the selected saw blade thickness, and that the clamping sleeve must also be able to contact the operating element in these different rotational positions.

In a non-described embodiment of the invention, the clamping sleeve has an inclined plane arranged in the path of motion of the drive dog which moves parallel to the lifting rod, as an inclined plane in the path of motion. When the transmission block moves, it contacts with the inclined surface of the clamping sleeve, and thus drives the clamping sleeve to rotate.

Claims (10)

1. portable jigsaw (10) has an elevating lever (18), and this elevating lever can be made guiding along its upper and lower bearing and move, and in its lower end a clamping device (20) that clamps saw blade (23) is arranged, and this clamping device has a closing sleeve (21; 121; 221; 321; 421; 521; 621; 721; 821), this closing sleeve has a collar that radially inwardly stretches out (46) in its free bottom, and this collar axially mounting also clamps the lug (49,50) of saw blade (23) bare terminal end (22) thus when clamped position, also is provided with closing sleeve (21; 121; 221; 321; 421; 521; 621; 721; 821) turn to the off-position, be fixed on the functional unit (27) on the casing, it is characterized in that described clamping device (20; 420) have closing sleeve (21; 121; 221; 321; 421; 521; 621; 721; 821) remain on saw blade (23) off-position and unclamp closing sleeve (21 once more with respect to elevating lever (18) by saw blade (23) is inserted clamping device (20); 121; 221; 321; 421; 521; 621; 721; 821) brake component (53 '; 54 '), thus functional unit (27) only closing sleeve (21 with synchro-meshing mode band on a direction of motion; 121; 221; 321; 421; 521; 621; 721; 821) move to the off-position from clamped position, that is to say, this functional unit is from off-position and closing sleeve (21; 121; 221; 321; 421; 521; 621; 721; 821) break away from engagement and return its initial position voluntarily.

2. jigsaw as claimed in claim 1 is characterized in that, adopts a slide bar (29) as rotating-operation member (27), and this slide bar drives closing sleeve (21 on its tracks; 121; 221; 321; 421; 521; 621; 721; 821) on one transmission link stopper (21 ') radially, and closing sleeve is rotated.

3. jigsaw as claimed in claim 1 or 2 is characterized in that, slide bar (329) is connected with closing sleeve (321) by haulage gear (327), particularly pull rope.

4. jigsaw as claimed in claim 3 is characterized in that, haulage gear one end that is made of pull rope (327) is wound on the closing sleeve (321), and the other end is fixed on the slide bar (329).

5. jigsaw as claimed in claim 2, it is characterized in that, the mode that slide bar (429) moves can be parallel to elevating lever (418) is bearing on the housing, and with a projection (430) be embedded into one be arranged on the casing side, can be in the skewed slot (488) of (489) (particularly switch sleeve) of the governor motion that closing sleeve (421) rotates, thereby the mobile governor motion (489) that makes of slide bar (429) rotates, and drives closing sleeve (421).

6. jigsaw as claimed in claim 5 is characterized in that, governor motion (489,589,689,789) is arranged on the ring-like guide rail in the mode that swings back and forth around closing sleeve (421,521,621,721).

7. jigsaw as claimed in claim 2 is characterized in that, slide bar (529) is made of tooth bar (529), the tooth engagement of the tooth of tooth bar and closing sleeve (521).

8. jigsaw as claimed in claim 7 is characterized in that, the governor motion (789) that is made of tooth bar is meshed with gear (789) on can be rotated to support on casing with its tooth (789 '), and this gear is coupled with the slide bar (729) that has tooth (729 ').

9. jigsaw as claimed in claim 8 is characterized in that, gear (798) is gone up other tooth (729 ') actings in conjunction that constitute spur gear with bevel gear (798) form and slide bar (729).

10. jigsaw as claimed in claim 1 is characterized in that, functional unit is made of rocking bar (27,227), this rocking bar free end and closing sleeve (21; 221) radial circumference contacts, and particularly collides closing sleeve (21; 221) radially transmission link stopper (21 '; 221 ').

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