DE3447828A1 - Grinding apparatus which can be driven by a motor - Google Patents

Abstract

This grinding apparatus can be used for grinding, smoothing and polishing, etc. preferably round bars and pipes. For this purpose, there is an open abrasive belt which is looped around the workpiece and both ends of which are held in two clamping or tensioning devices of the grinding apparatus. Via a movement apparatus, a gear mechanism which can be driven by a motor in one direction of rotation sets the two clamping and tensioning devices, and thus also the abrasive belt, in an alternating synchronously opposed motion, which draws the abrasive belt over the workpiece and thus effects the grinding action.

Description

ÜIPL.-ING. WALTER BRUNNENKANT _ANR:

-λ -

Motor-driven grinding device

The invention relates to motor-driven grinding apparatus

for sanding belts.

Such electromotive grinding devices enable the machining

Lifting processing and shaping of workpieces as well as polishing, smoothing, mechanical rust removal and paint removal from surfaces of any kind.
There are known electromotive grinding apparatus for grinding belts, in which an endless grinding belt with the underside of the grinding

medium carrier is guided and tensioned over two parallel rollers. Here, one roller is driven by the electric motor and the other is designed as an idling roller.
The grinding belt is at least over a section of the length so stretched with its underside over a smooth plate

guided and supported,
r The workpiece to be machined or smoothed is against the

The abrasive side of the abrasive belt is guided in the area J supported in this way.

Here, even micrographs can be achieved.

There are also known grinding machines of this type, in which the idle Roller is formed with an elastically yielding coating, for example foam rubber, over the tread, so that with the over they can be ground out running grinding belt inner radii.

Electromotive hand grinders are also known as vibrating

known grinder, in which a sanding belt over an elastically lined, flat sanding pad is clamped and fastened. The sanding pad is designed and connected to an electric motor, that the sanding pad is set in targeted oscillation by the running of the motor, which produces the grinding effect.

In another type of grinding apparatus, a round, rigid or elastic, flat disk that is coated with the abrasive, for example in the form of sandpaper, is set in rotation by an electric motor.
* 35 The rotating grinding wheel is over the to be processed or to

DIPL.-ING. WALTER BRUNNENKANT _VMJ . _{I (rnni} ,

smoothing surface.

With these grinding devices, all essentially flat and slightly outwardly, possibly also inwardly, curved surfaces can be processed and smoothed.
Edges can also be chamfered with them without difficulty.

The grinding of round rods and tubes creates considerable difficulties.

In this case, the grinding apparatus with its grinding surface must be sanded at a constant speed and pressure all around Rod to avoid a polygonal grinding result. Since the grinding surface is only in a narrow strip, theoretically in a coat Mn ie, attacks, the grinding performance is very low. The known grinding devices can only be used for this purpose if there is sufficient free space around the rod to be ground consists.

Steel rods are often used for railings and grilles, which e.g. have to be sanded off before the paint is renewed, which is only difficult with the known electromotive sanding devices and is insufficiently possible. ·

The invention aims to provide a remedy here.

The invention, as characterized in the claims, solves the task of grinding, smoothing, polishing, removing rust and paint from round rods and tubes in that an open grinding belt is looped around the workpiece to be ground with both ends on two clamping or clamping devices of the grinding apparatus according to the invention are attached, with a motor-driven gear unit displacing the two clamping and clamping devices in an alternating, synchronous, but opposite movement via a movement device. This movement is transferred to the sanding belt, which is pulled evenly over the workpiece and produces the sanding effect.
This invention essentially achieves the following advantages:

copy

UII ¹ L.-ING. WALTER BRUNNENKANT _AWR: -, 902024

The distance between the workpiece and the hand grinder remains constant, which results in an even grinding effect. The sanding belt lays itself on the contour of the workpiece with a relatively large wrap angle and can thus be used over a large area and true to the contour (i.e. without polygon formation) can be processed with high efficiency.

Since only the relatively thin sanding belt has to wrap around the workpiece, round rods and tubes can also be used in tight spaces that are difficult to access, e.g. in front of walls, in corners, etc., without difficulty all around be sanded.

In the following the invention is only based on two exemplary embodiments explained in more detail with reference to drawings.

a grinding apparatus according to the invention in the form of an electromotive grinding apparatus in a side view in a partially sectioned illustration, a section along the section line l-l of FIG. 1. the grinding apparatus according to the invention according to FIG. 1 and FIG. 2 with various additions according to the invention

facilities.

11 a section through a grinding apparatus suitable for driving

by a hand drill.

The basic structure of the electromotive grinding apparatus according to the invention consists of a housing (1) in which an electric motor (2) is arranged, which can be switched on via a switch (3).
The switch (3) is preferably accommodated in a part of the housing (1) designed as a handle (4).

The electrical current required for operation is fed into the housing (1) via the supply line (5) and via not shown, internal lines and possibly regulating and / or control devices are fed to the electric motor (2).

It demonstrate Fig . 1 Fig . 2 Fig .3-10

DIPL.-ING. WALTER BRUNNENKANT AWR: 1 ^) ₂ 02H

The electric motor (2) acts on a transmission (6), which is an example of the The embodiment shown consists essentially of a pinion (9), a gear (10), eccentric (11) and connecting rod (12). Whereby also other gear forms to realize the inventive idea possible are.

The rotor (7), which is mounted on the output side in the bearing body (8), acts with its pinion (9) with the gear (10) which is rotatably mounted in the bearing body (8), as not shown in detail. The gear wheel (10) is connected to the eccentric (11), which cooperates with the connecting rod (12).

A spacer washer (13) is required for lateral guidance of the connecting rod (12) provided for the gear (10).

The gear (6) acts on the movement device (15), which in the For example, the embodiment shown consists essentially of a lever (17), a shaft (18) and a rocker (19).

For this purpose, the connecting rod (12) has its eye (14) over a bolt (16) rotatably connected to the lever (17), which sits non-rotatably on the shaft (18), which is in two bearings (20) in the downwardly drawn Feet (21) of the housing (1) is mounted.

The rocker arm (19), the two, are non-rotatably connected to the shaft (18) Has clamping or tensioning devices (22) for fastening a grinding belt (23).

The sanding belt (23) is inserted so that it, as shown in Fig. 2, A round workpiece (25) is wrapped around the side (24) covered with abrasive.

When starting up the hand grinder according to the invention, what by When the switch (3) is actuated, the gear (10) is set in rotation by the electric motor (2) via the pinion (9). The eccentric (11), which controls the connecting rod, rotates with the gear (10) (12) moves in an oscillating manner and so does the rocker arm with the lever (17)

(19) set in a rotary-oscillating motion.

This rotary-oscillating movement moves the grinding belt (23) alternately over the workpiece (25), the grinding effect being generated. Since the sanding belt (23) performs an alternating movement

the distance X between the hand grinder and the workpiece is constant. ₁

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¹ JIPL. ING. WALTEK BRUNNENKANT ANR: 1 902

In Fig. 3 and Fig. 4, the hand grinder according to the invention is with a Additional device (27) to increase the turning angle of the. Sanding belt (23) shown.

The additional device (27) is with its base plate (28) on the feet (21) screwed on.

Two rollers (30) are rotatably mounted on the two webs (29) so that that they encompass and constrict the grinding belt (23) from the outside. As a result, the workpiece (25) has an enlarged wrap angle covered and ground.

_1 Q To make the hand grinder easier to use, as in

Fig. 5 and Fig. 6 shown by way of example, a guide device (32) be attached to the feet (21), which consists of at least one roller (33) consists, which is elastically mounted on a spring element (34). The running surface (35) of the roller (33) is turned so hollow that the Roll (33) leading on the round workpiece (25) rolls.

This guide device (32) makes the grinding belt (23) uniform kept tense.

With the hand grinder, as shown and explained in FIGS is, only workpieces (25) can be ground or processed if they are arranged so that they can be looped by the grinding belt (23) are.

In order to have roundings accessible on one side with the hand grinder according to the invention To grind, as shown for example in Fig. 7 and Fig. 8, a device (36) is attached to the feet (21).

The device (36) consists of a base plate (28) with pairs opposite lateral supports (37), between each of which a deflection roller (38) is rotatably mounted.

With the arrangement of 2 parallel deflection rollers (38), as in FIG. 7 and Fig. 8, the loose, non-tensioned grinding belt (23) with the outwardly facing abrasive-coated side (24) over these deflection rollers (38) are guided so that a pocket-like loop (39) is formed between them.

The hand grinder is to be guided in such a way that the Rounding (40) comes to rest in the pocket-like loop (39).

DIPL.-ING. WALTER BRUNNENKANT _{ANR: ] () ü2 ü2}

In Fig. 9 and 10 a similar device (44) is shown which however, it is only equipped with a deflection roller (38) which is advantageously provided with an elastic covering (40) which it With the sanding belt (23) inserted tightly, it enables other profiles, e.g. fillets (41) to be sanded.

The grinding belt (23) can, for example, through a U-shaped angle (43) be stretched.

The part of the angle (43) lying on the back of the sanding belt acts as a Counter bearing (45), in the area of which the grinding belt (23) is also used for surface grinding can be used.

The hand grinder according to the invention shown in FIG. 10 is on the side Equipped on the housing (1) with a push-on device (42), not shown in detail, onto which a sanding belt roll (46) can be pushed, so that when the grinding effect of the grinding belt (23) wears or decreases, it is replaced by repositioning it from the grinding belt roll (46) can be.

In Fig. 11 is another embodiment of the inventive grinding ' Apparates shown, which is suitable to be connected to a separate drive machine, for example a hand drill (47). *

The housing (48) is provided with, for example, a cylindrical receptacle (49) into which the corresponding cylindrical neck (50) of the hand drill (47) fits and is clamped by a clamping device (not shown).
The driving force of the drill (47) is transmitted via the drill chuck (51) and the pin (52) to the gear (6), which in this embodiment is designed as a double crank (54) and is rotatably mounted in the bearings (53).

The movement device (15) consists of the two crank bearings (55) with the smooth pull cords (56) attached to them, which are passed through the two round openings (57) and each with a Clamping and tensioning device (22) for fastening the grinding belt (23) are connected.

For grinding, it is clamped into the clamping or tensioning device (22) Grinding belt (23) stretched around the workpiece (25).

The crankshaft (54) is driven by the drive of the drill (47)

ÜIPL.-ING. WALTER BRUNNENKANT A.WR: l go2 02H

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rotates, with an alternating synchronous one in the two pull cords (56) Movement is generated, which is transmitted to the grinding belt (23) and creates the grinding effect.

The guide of the pull cords (56) in the parallel openings (57) brings about a rectification of the alternating movement.

The inventive idea can be realized in different ways.

The versions shown here in the drawing are only possible examples. 10

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Claims (10)

DIPL.-ING. WALTER BRUNNENKANT ANR: 1 002 02; -1 - CLAIMS 1. Motor-driven grinder for grinding belt essentially consisting of at least one statically determined housing part, the at least one gear with means for torque transmission is provided and can be connected to a motor, supported statically determined, characterized in that the gear and a movement device, which are provided with two parallel fastening devices for a sanding belt is, are designed and arranged such that the exerted by the engine on the transmission, continuously rectified Rotary movement acts on the movement device in such a way that the two fastening devices for the sanding belt of an alternating, opposing movement or acceleration are exposed, with the two ends of one placed in a smooth loop Sanding belt piece can be fastened aligned so that the direction of movement in the longitudinal extent of the sanding belt falls. 2. Motor-driven grinding apparatus according to claim 1, characterized in that that an EIt.-motor integrated in the housing part is provided to drive the grinding apparatus. 3. Motor-driven grinding apparatus according to claim (2) thereby characterized in that in the housing part an electrical connection, a speed controller and / or a switch are integrated. 1. Motor-driven grinding apparatus according to claim 3, characterized in that that the electrical connection consists of a plug-in accumulator. 5. Motor-driven grinding apparatus according to claim 1, characterized in that that the means for torque transmission is designed so that it can be clamped in a known drill chuck can, and that the housing part in the area of the means for rotating DIPL.-INC. WALTER BRUNNENKANT _A m _{R: λ 902} torque transmission is designed and provided with a receptacle in which the neck is provided for the drive Hand drill can be fastened, in the drill chuck the means for torque transmission can be clamped. Γ) 6. Motor-driven grinding apparatus according to claim 2 to 5 thereby characterized in that the housing is provided at least at one point with a handle or is formed into a handle. 7. Motor-driven grinding apparatus according to one or more claims 1-6, characterized in that a device is provided or can be provided on the housing that the over a to grinding essentially round workpiece laid loop of the grinding belt through transverse to it, preferably as Rolling formed deflection is guided so that the grinding belt touches the workpiece with the largest possible looping win- '' kel encloses. 8. Motor-driven grinding machine according to one or more claims 1 - 6 characterized in that a Device is provided or can be provided which supports the grinding apparatus in the operating position against the workpiece with a slide or roller adapted to the shape of the workpiece via a preferably elastic element.
25th 9. Motor-driven grinding apparatus according to one or more of claims 1-7, characterized in that a device is provided or can be provided on the housing, which is provided with at least one deflection running parallel to the fastening devices for the grinding belt, over which the loop of the grinding belt can be guided , wherein the deflections remove the abrasive belt on the sides not covered with abrasive, preferably over a relatively large area and / or with rollers, which are advantageously provided with an elastic coating.
<i 35 DIPL.-ING. WALTER BRUNNENKANT _A y _{R: ,, i () 2 u2} , _{ 10. Motor-driven grinding apparatus according to one or more of the preceding claims, characterized in that the housing is provided or can be provided with a device that picks up the sanding belt wound in a roll and keeps it ready for use, with the belt straight from the roll can be successively fed to the two fastening devices for the grinding belt. ³⁵ copy