JPS63120081A - Protective hood for portable machine tool, particularly, grinder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a protective hood for a handheld machine tool, particularly a polishing machine, in which the protective hood is attached to a tightening screw for tightening a tightening pan P on the side of the protective hood. It relates to a type that is tightly tightened to the tightening neck on the machine side. In known protective hoods, the clamping screw has a slit or hexagonal hole in the screw head, the clamping screw passing through one clamping band lug and having a threaded portion in the other clamping band lug. , for example, by screwing into a nut welded to the tightening band ear.
Ru. To tighten or loosen the tightening band, a tool that fits the head of the tightening screw, such as a screwdriver or a hexagonal screwdriver, is required. This tool must be carried separately. Tightening the slitted screw with a screwdriver with an excessively small blade will damage the slit. Additionally, a screwdriver that is too small will not have the necessary tightening force to reliably and safely tighten the protective hood. As a result, the protective hood may loosen.
A dangerous situation arises for Nagisa when using the Eshi machine tool. Further, with a screw having a hexagonal hole in the screw head, a similar result occurs if dust is deposited in the hexagonal hole and the hexagonal head screwdriver cannot be properly installed in the hexagonal hole. Regarding this, 4? of claim 1? The protective hood according to the invention for a hand-held machine tool, in particular a grinding machine, has the following advantages:

This means that the protective hood according to the invention can be tightened and loosened or removed without using additional auxiliary tools. The structures of the protective hood and the tightening band themselves are the same as those conventionally known. The lever, which is irremovably attached to the clamping band, transmits sufficient torque to rotate the clamping screw, thereby ensuring a reliable and safe tightening of the protective hood. It is easy to handle and has a quick attachment/detachment function. The clamping screw ensures reliable tightening of the protective hood even in the case of large differences in the diameter of the clamping neck on the machine tool side. The structure of the protective hood according to the invention is simple. The protective hood has only a few component parts and can therefore be manufactured as a whole easily and inexpensively. A further advantage is that there is a constant holding force in the clamping position with the lever pivoted inwards, which holding force is independent of the magnitude of the S degree torque on the clamping screw. The protective hood also serves as a very robust adapter and is not affected by external forces or dirt.

The measures set forth in the second and subsequent claims indicate advantageous embodiments of the protective hood according to the first claim. The measures set forth in the following claims represent particularly advantageous embodiments. Such eccentric disc clamping devices can be operated quickly and easily without the need for additional tools.

The invention will now be explained with reference to the illustrated embodiment.

1 to 4 show a first embodiment of a protective hood 10 suitable for hand-held machine tools, in particular for grinding machines. In this case, the polishing disc is in particular an L-shaped polishing disc. This grinding wheel has a fixed receiving part screwed onto the protruding part of the drive shaft of the grinding wheel, and this fixed receiving part supports a cylindrical clamping neck on the flange. A drive shaft passes through the center of this cylindrical clamping neck, and the clamping neck has at least a substantially smooth outer circumferential surface. This clamping neck is, for example, a cast part. Protective hood 1 on this tightening neck
0 is exchangeably fixed. For this fixing, a clamping band 11 consisting of a thin plate fixedly connected to the protective hood 10 serves, which extends, for example, over an angular range of approximately 3200 degrees and which separates both clamping band sections. 12.13
It has bent ears 14.15 at its ends, which ears 14.15 extend at least approximately parallel to each other, for immovably fastening the protective hood 10 on said clamping neck. Then, they are tightened together using the tightening screws 16.

The protective hood 10 has a flange device 17 that engages and acts on a tightening screw 16 to enable tool-free tightening. This device consists of a flattened end 1 of a tightening screw 16.
8 and has a lever 19, which in this case is formed of two legs 20, 21 of spring steel wire bent approximately into the shape of hairpins, which legs are The leg ends 22, 23 of different lengths and bent approximately at right angles are inserted into the respective holes 24, 25 of the flat end 18 of the clamping screw 16, and The screws 16 are supported pivotably about their respective axes, in which case these axes are connected to the tightening screws 16.
perpendicular to the longitudinal direction of

The lever 19 is connected to the lower tightening band section 13 in FIG.
It extends almost along the arc shape of the land, and is cultivated in almost the same arc shape. The lever 19 extends approximately within this tightening band section 13, as shown in FIG.

At the end opposite the leg ends 22, 23, the lever 19 has a grippable end 26 extending from the arcuate section. As shown in FIG. 1, the lever 19 is located on the side opposite the tightening band section 12 on which the cover hood is fixedly supported. The lever 19 itself is the first
It is held in the tightening position shown in the figure, in which the lever 19 is pivoted towards the adjacent tightening band section 13. This position is produced in this case by spring elasticity and by the fact that both legs 20, 21 are made of spring steel wire. Both legs 20 and 21 are bent in a direction toward each other before assembly. As a result,
In the assembled state shown in FIGS. 1 to 4, the leg end 22
．． 23 is held in the hole 24.25 by a spring force.

In another embodiment, the holes 24 and 25 may be arranged along the central axis of the tightening screw 16 (not shown). In contrast, in the embodiment shown, the bores 24, 25 are arranged on a connecting line extending obliquely to the central axis of the screw 16 (FIG. 1). That is, the holes 24, 25 are located on this connection line at a distance n at a distance a. In the unassembled state, the short leg 21 is sufficiently flush with respect to the long leg 20, so that the short leg 21
This shorter leg 21 provides a spring-elastic preload to the lever 19 when the leg end 23 of the lever 19 is inserted into the hole 25.

Both legs 20 are in the tightened position when the lever 19 is rotated to the position shown in FIG.
A deflection of 21 occurs, the reaction force of which presses the lever 19 against the tightening band region 13 and holds it in this position. distance a
and the above-mentioned "n", so that a smaller return force is applied to the lever 19 in the outwardly pivoted position than in the inwardly pivoted tightening position shown in FIG. I can do it.

The tightening screw 16 is connected to the female thread portion 2 with the thread section 27.
8, this internally threaded part 28 consists in this case of a nut connected to the ear 14, for example by welding.

The clamping screw 16 is supported on the other lug 15 with its axial abutment surface 29, which abutment surface is provided on a collar 30 that is integral with the clamping screw 16.

The flattened end 18 to which the lever 19 is connected adjoins this axial abutment surface. In this configuration, the lever 19 is configured as a crank for rotating the tightening screw 16. The thread section 27 and the female thread section 28 belonging to f'LK have a small pitch thread, for example a thread M8 with a pitch of 0.75.

To securely clamp the protective hood 10 on the clamping neck of the hand-held machine tool, the lever 19 is pivoted from the clamping position shown in FIG. 1 to the release position 3 shown in FIG. let me,
Next, for tightening, tighten the tightening screw 16 by turning the lever 19. The lever 19 can however be pivoted back again within a narrow rotational angle range, for example approximately plus or minus 10 degrees. If the tightening bolt 16 has been tightened to 1A and the lever 19 has exceeded its return range and is further at an angular value of, for example, 160°, then the lever 19 cannot be swiveled, which is the most unfavorable case. In order to move to the fixed tightening position, two possible means arise. That is, either rotate the 1-no-bar 19 160 degrees in the opposite direction and return it, or rotate it further by 160 degrees. Due to the small thread pitch and the spring-elastic flexibility of the clamping band 11, only very small clamping tensions are generated in the clamping band 11 in the first possible solution.

In the second possible solution, a very high torque must additionally be applied to the lever 19, which acts as a crank.

The clamp device 17 according to the first embodiment has the following advantages. That is, sufficient force and torque necessary for tightening can be applied to the lever 19, which is securely attached to the protective hood 10, without using a large force.

The dust protection hood 10 can be reliably and safely tightened. No special tools are required for this purpose. Easy to handle. Even if there is a deviation in the diameter of the tightening neck on the machine tool side, reliable and safe tightening of the protective hood 10 is guaranteed. Furthermore, the structure of the protective hood 10 is simple. The protective hood 10 has only a few components and can be produced overall at low cost. A constant and constant tightening force is guaranteed in the tightening position where the lever is turned toward the wire-coated band side. This constant tightening force is independent of the torque applied to the tightening screw 16. Also, there are no visible wear parts that would reduce the protection tool F tightening force. The clamping device 1T can also be used semi-permanently as an extremely robust adapter. It is also unaffected by external influences, in particular dust or other contamination.

In the second embodiment shown in FIGS. 5 and 6, the first
Parts corresponding to the embodiment are given numerals incremented by 100 to avoid repeating the description of the first real box example.

In the second embodiment, the protective hood 10 is constructed in a similar manner. However, the lever 119 is in this case constructed as a single rod lever 131. The tightening screw 116 has a two-pronged hawk 132 which axially follows the collar 30, and between the hawk legs 133, 134 of this hawk a bearing part 135 is inserted, which part is provided at the end of the lever 119. There are n. Both bearing fork legs 133, 134 and bearing part 1
A bearing pin 136 passes through the bearing pin 136 at right angles, and thereby the lever 119 is held on the tightening screw 116 so as to be pivotable about the axis of the bearing pin 136.

In this second embodiment, the lever 119 is also held resiliently in the inwardly pivoted clamping position shown in FIG. This spring-elastic holding state is produced by an outer spring 137, which is designed as a torsion spring 138.

This spring is connected to a pin 1 fixedly provided in the protective hood 110.
39 and supported by one spring end 140 in the protective hood 110.

The other spring end 141 engages the lever 119 and urges it elastically into the tightened position shown in FIG. This free spring end portion 141 has a bent hook-shaped portion 142, which is approximately the same as shown in FIG. It extends at right angles. The hook 142 is further followed by an end leg 143 which is bent approximately at right angles therefrom and which is also oriented at right angles to the direction of extension of the lever 119 and which is bent at a substantially right angle. It goes around one side of the. The spring 137 presses the lever 119 with a hooked portion 142. The end leg 143 in this case engages around the lever 1190! ? , 6, to prevent some slippage of the spring end 141 when the lever 119 is moved to the outwardly pivoted position shown in dashed lines in FIG.

Also in the third embodiment shown in FIGS. 7 and 8, the lever 21
9 is designed as a single lever, which can be a sheet-metal molded part, for example. The clamping device in this embodiment is configured as an eccentric disc type clamping device 244.
ing.

The lever 219 has end-side clamping surfaces 246 and 247 extending eccentrically with respect to its central pivot axis 245, these clamping surfaces being located at the ears of one clamping band section 213. 215 indirectly. In the area of this end, the lever 219 has a two-pronged fork 248, in the two fork legs 249, 250 of which a bearing pin 251 passes with the play of movement, so that the lever 219 is covered. It is rotatably supported on a bearing pin 251.

The bearing pin 251 extends at right angles to the clamping screw 216. This bearing pin has an internally threaded hole 252 into which a threaded section 253 at the end of the clamping screw 216 is adjustably screwed. Latter thread division 25
For example, if you swage the screw threads in step 3, you can prevent the needle from falling off.

The clamping screw 216 rests with an axial abutment surface 229 in the ear 214 of the clamping band section 212. This contact surface 22
9 is a collar 230 configured as a screw spatula F on the end side.
The screw head can also have a machined surface on the outer tool hook for adjustment. This
The section of the tightening screw 216 that follows passes through the hole in the other ear 215 with a play in movement. This bolt section is separated from the thread section 253, which is connected to the bearing pin 251.
The screw is inserted into the female threaded hole 252 of. Support pin 2
By rotating the tightening screw 216 with respect to 51,
For example, adaptation to different tightening neck outer diameters is possible.

The ear 215 has a bearing 254 on the lever 219 (Ill), which is attached to both hawk legs 249.25 of the hawk 248
It has a guide part 255 which is fixed between zero and which guides the lever 219 in its end region. Guide part 25
On both sides of 5, the bearing part 254 has flat support surfaces 256, 257.
The clamping surfaces 246 and 247 on the end side of the lever 219 are supported on the supporting surface.

In this embodiment, the bearing 254 consists of an additional component which is supported on the ear 215, for example fixedly mounted on the ear 215.

A tightening screw 21 is installed in the flange 230 as a tightening screw head.
6, the tightening screw 216 can be adjusted to suit the initial tightening force required in connection with the tightening neck of the machine tool. In this case thread division 253
There are differences in the degree of screwing into the bearing pin 251.
For tightening, the lever 219 is then pivoted about the axis 245 into the tightening position shown in FIG.

At this time, the clamping force is applied to the support surface 256 based on the gradually increasing eccentric distance of the clamping surfaces 246 and 247 from the axis 245.
, 257 and, in turn, to the ear 215. The two tightening band sections 212, 213 are tightened together to the required extent. The protective hood 210 is now tightly fastened to the neck.

To remove the protective hood 210, pivot the lever 219 outward to release the tightening force. Based on the eccentric distance, both ears2
Since the distance between 14 and 215 becomes larger, the tightening force of the rainbow protection hood 210 against the tightening neck is loosened.
The protective hood P can be removed from the tightening neck.

The eccentric disk type clamping device 244 has a relatively simple structure,
Manufacturing cost is low and handling is easy. Also, the protection tool 210 can be inspected without any additional tools. The eccentric disk clamp 244 can be handled quickly, easily and without special expertise.

The "opening and closing" of the clamping device can be carried out particularly advantageously if the grinding wheel of the polishing machine is arranged horizontally.

Since the clamping screw 216 is adjustable, the clamping device can be adapted to different clamping neck diameters if required.

This adaptation is advantageously carried out without the lever 219 being tightened. In this case, the tightening screw 216 is adjusted by grasping the collar 230 by hand and rotating it.

If necessary, it is also possible to use a tool, for example pliers.

The protective hood 310 according to the fourth embodiment shown in FIG. 9 is identical in all important parts to that of the sixth embodiment.

The difference is that the bearing 354 is an integral part of the ear 315 in this embodiment. The ear 315 also has a protrusion 358 that is pushed out toward the bearing pin 351.
p, this part forms a guide 355 for the lever 319, which engages between the forked legs of the forked hawk 348 at the end of the lever 319. Both sides 110 of the ridge 358 are provided with flat support surfaces 356, 357, which are formed by the outer surface of the ear 315 itself. The protrusion 358 extends beyond the ear 315 and from there to the connection area of the tightening band 313 with the ear. This area is designated by 359 and continues approximately at right angles to the raised portion of the ear 315 area (FIG. 10).

In this manner, the protrusion 358 at the same time serves as a reinforcing lip that reinforces the ear 315 and the region of the tightening band 313 that follows it. Exactly in this range, the maximum force is applied each time the eccentric disc type clamping device 344 is operated, so it is possible to effectively suppress the deformation force of the tightening band to some extent in this range by simple means. I can do it.

The axial abutment surface 329 of the clamping screw 316 is formed in this embodiment by an annular collar 330, which can be integral with the clamping screw 316, for example. Annular tsuba 33
0 is followed by an end section 360, the end face of which is machined with a slit 361 for hanging the blade of a screwdriver. On the collar 330 and/or on the end section 360, an outer tool hook can be provided with a surface, for example as a flattened side part, so that when adjusting the tightening screw 316 this outer tool hook can be provided with a tool on the surface, e.g. You can hang pliers. Alternatively, a screwdriver may be inserted into the slit 361.

[Brief explanation of the drawing]

1 is a schematic plan view showing a portion of the protective hood for a hand-held machine tool according to the first embodiment in the tightened position, FIG. 2 is a side view of a portion of the protective hood of FIG. 1, and FIG. A view of a part of the protection tool F shown in the figure as seen from the direction of arrow I in Fig. 1.
The figure is a schematic plan view of a part of the protective hood in a state in which the lever is pivoted outwards, which corresponds approximately to that shown in FIG. 1, and FIG. 6 is a side view of the protective hood of FIG. 5, and FIG. 7 is a schematic plan view of a portion of the hunting hood F according to the sixth embodiment, which corresponds approximately to FIG. 1. 8 is a side view of the protection tool y shown in FIG. 7, and FIG. 9 is a schematic plan view of a portion of the protection hood according to the fourth embodiment, substantially corresponding to FIG.
Fig. 10 is a schematic plane color showing a part of the protection tool F in Fig. 9 with the lever removed and added, and Fig. 11 shows a part of the protection hood in Fig. 10 in the direction of arrow X in Fig. 10. Karami 7
I! :-.

Claims (1)

[Claims] 1. A protective hood for a hand-held machine tool, wherein the protective hood is tightly tightened to a tightening neck of the hand-held machine tool by a tightening screw that tightens a tightening band on the protective hood side. For those of the type, the tightening screws (16; 116; 216; 316
), the clamping device (
17) A protective hood for a hand-held machine tool. 2. Protective hood according to claim 1, in which the clamping device (17) engages and acts on the end of the tightening screw (16). 3. The clamp device (17) is connected to the lever (19; 119; 2
19; 319), and the lever has a tightening screw (16; 1
16; 216; 316) so as to be pivotable about an axis extending substantially perpendicular to the axis of the tightening screw protective hood. 4. The lever (19; 119; 219; 319) is configured in an arc shape that substantially follows the arc shape of the tightening band (11; 111; 211; 311), and that the lever (19; 119; 219; Protective hood according to claim 5, having a free gripping end (26) extending in the plane of the arcuate section and extending from the arcuate section. 5. The lever (19; 119; 219; 319) supports the clamping band section (12; 1) immovably on the cover hood.
12; 212; 312). 6. A patent claim in which the lever (19; 119; 219; 319) is automatically held in the tightening position in which the lever (19; 119; 219; 319) is pivoted toward the tightening band (13; 113; 213; 313) on the lever side. The protective hood according to any one of items 3 to 5. 7. The tightening screw (16; 116) has its thread section (27
) into an internally threaded portion (28) of one of the clamping band ears (14) extending from the clamping band section (12; 112) and with a clamping screw (16;
; 116) is attached to the other tightening band ear (15) with the tightening screw (
16; 116) on the axial abutment surface (29) on the collar (30; 130), and the lever (19; 119) is supported by the tightening screw (16; 1
16), the end section (1) on the axial abutment surface (29) side
7. The protective hood according to claim 1, wherein the protective hood is configured as a crank that engages with the locking screw (16; 116) and rotates the tightening screw (16; 116). 8. The thread section (27) and the female thread section (28) belonging thereto are minute pitch threads, for example, pitch 0.75.
8. The protective hood according to claim 7, having a thread M8. 9. Protective hood according to any one of claims 6 to 8, in which the lever (19; 119) is held resiliently in the tightened position in which the lever (19; 119) is pivoted inward. 10. The lever (19) has two legs (20, 21) bent approximately into hairpins, both legs (
20, 21) have different lengths, and the leg ends (22, 23) of the two legs are bent at a substantially right angle,
According to one of the claims 3 to 9, the clamping screw (16) engages in its respective bore (24, 25) in the end section (18). Protective hood. 11. Both holes (24, 25) are spaced apart from each other by a distance (a) along the central axis of the tightening screw (16) or along a connecting line extending obliquely to this central axis; ,
Protective hood according to claim 10, wherein the lever (19) is arranged in such a way that the lever (19) is forced into the tightening position by a spring force acting from the short leg (21). . 12. The lever (119) is configured as a single rod lever and has two adjacent hawk legs (133,
134) and a bearing part (
Any one of claims 3 to 9, which is rotatably supported at the end of the tightening screw (116) about an axis by a bearing pin (136) passing through the clamping screw (135). The protective hood described in item 1. 13. The hawk legs (133, 134) are attached to the tightening screws (116).
), and the bearing (135) is connected to the lever (119).
13. A protective hood according to claim 12, which is provided at an end of the protective hood. 14, an outer spring (137) is supported at one end (140) in a tightening band section (112) attached to the cover hood and at the other end (141) in a lever (11
Protective hood according to any one of claims 3 to 9, which is supported by the lever (119) and spring-elastically moves the lever (119) into the tightening position. 15. The spring (137) is configured as a torsion spring (138) or a footed spring, the freely projecting spring end (141) of which rests against the outer back surface of the lever (119) and 15. Protective hood according to claim 14, having a curved barb (142) extending transversely at right angles to the rear surface. 16, the barb (142) is followed by an end leg (143) extending generally perpendicularly therefrom;
16. Protective hood according to claim 15, characterized in that the lever (119) engages on one side of the lever (119) at right angles to the direction of extension of the lever (119). 17. The clamp device is an eccentric disk type clamp device (244;
344), the protective hood according to any one of claims 1 to 6. 18, the lever (219; 319) is aligned with its pivot axis (
One side of the clamping surface (245) extends eccentrically with respect to (245)
18. Protective hood according to claim 17, characterized in that it has a clamping surface (46, 247) that abuts the clamping band ear (215; 315) directly or indirectly. 19, the lever (219; 319) is a bifurcated hawk (24
8; 348), and both hawk legs (249,
A bearing pin (
251; 351) so as to be pivotable about a pivot axis. 20, The support pin (251; 351) is attached to the tightening bolt (21
6; 316) and has a female threaded hole (252), into which a tightening screw (252) is inserted.
20. Protective hood according to claim 17, wherein the threaded section (253) at 16; 316) is adjustably screwed. 21, the tightening screw (216; 316) is attached to the tightening screw flange (2
30; 330) axial abutment surfaces (229; 329)
, the threaded section supported by the tightening band lug (214; 314) and continuing to the abutment surface is connected to the other tightening band lug (215; 31).
5) is inserted into the hole of the lever (
21. Protective hood according to claim 17, wherein the protective hood projects towards the bearing pin (251; 351) of the protective hood (219; 319). 22, One tightening band ear (215; 315) has a support part (254; 354) on the lever (219; 319) side.
and a guide portion (255; 355) whose bearing portion engages between both fork legs (249; 250) of the lever (219; 319), and a guide portion (255; 355) on both sides of the guide portion (255; 355). It has a certain support surface (256, 257; 356; 357), on which the clamping surface (2
46, 247) is supported. Protective hood according to any one of claims 19 to 21. 23. Protective hood according to claim 22, wherein the bearing (254) is an additional member supported on the tightening band ear (215). 24, the support part (354) is the tightening band ear (315),
23. A protective hood as claimed in claim 22, which is an integral component thereof. 25. A bulge (358) forming a guide portion (355) engaging between the two fork legs, with the tightening band ear (315) being pushed out from its plane towards the bearing pin (351).
It has tightening band ears (35
25. Protective hood according to claim 24, characterized in that 1) is followed by an outer surface forming a flat support surface (356, 357). 26, the protrusion (358) extends from the tightening band lug (315) to the connecting area of the tightening band (313) following the tightening band lug (315), and has a reinforcing rib in the connecting area. 26. A protective hood according to claim 25. 27, one screw head (2
Claim 21 formed by 30)
The protective hood according to any one of paragraphs 26 to 26. 28. The axial abutment surface (329) of the tightening screw (316) is formed by an annular collar (330), and one end of the tightening screw (316) is formed on the annular collar (330). A section (360) follows, said end section (36
0) has a slit (361) on the end face, and the annular collar (330) and/or the end section (360) has a tool hooking surface, for example a flat surface on both sides. A protective hood according to any one of claims 21 to 26.