WO2008040364A1

WO2008040364A1 - Electrical hand planer

Info

Publication number: WO2008040364A1
Application number: PCT/EE2007/000020
Authority: WO
Inventors: Andres Murdvee
Original assignee: Andres Murdvee
Priority date: 2006-10-05
Filing date: 2007-10-05
Publication date: 2008-04-10
Also published as: EE200600033A

Abstract

The present invention comprises the electric hand planer where blade (12) is set in motion so that the trajectory of blade (12) points is an enclosed curve in the shape of an ellipse. This trajectory of blade (12) points is achieved with eccentric (8) connected with motor shaft (9) and attached to sole (1), to which is attached blade (12). The planer consists of sole (1), motor housing lower part (2), sleeves (3), eccentric (8) attached to the inner ring of bearing (6) in fixing base (4), motor shaft (9), motor bearing (10), blade (12) attached to sole (1) slot (11), fixing element (13), blade (12) angle regulation element (14), blade (12) fixing plate (15), motor housing (16), grip (17).

Description

Electrical hand planer

TECHNICAL FIELD

The present invention relates to wood surface processing tools and more specifically concerns a tool for planing wood.

STATE OF THE ART

The already existing solutions for wood surface processing include hand planers and industrial planers. The solutions that can be considered closest to this invention are electric hand planers. For instance, United States of America patent No. US6249982 describes a hand planer with the cutting blade consisting of blades attached to longitudinal slits in the planer shaft. As the shaft begins rotating, the blades cut off chips from the wood surface. International patent application No. WO2004076140 and Chinese patent No. CN2361447 describe an electric hand planer that processes wood surface with a roller.

German patent No. DE19719418 describes a stationary industrial bench for cutting veneer and thin boards with the cutting blade set in mechanical oscillation or vibration. Chinese patent No. CN2265278 describes a vibrating hand planer with the cutting blade attached via an electric motor to the foundation that moves forwards and backwards.

The deficiency of such already existing solutions is that the planed surface is not smooth because the wood fibres are destroyed. That is why the wood must be polished with sandpaper after planing. Then, depending on the movement speed of the blade and the desired surface quality level, the wood surface is either dampened for the fibres to rise and polished, or polished after the first lacquer or paint layer application.

As the blade movement speed of the so-called electric rotor planers is very high, the blade must be made of elastic material to prevent it from destroying the wood surface, for instance when planing knots. Yet this reduces the lifetime of the blade because it requires frequent sharpening. The closest known solution is described in Great Britain patent No. GB980809 which specifies improvements to the surface treatment tool by a concept of using oscillation to drive a cutting blade to plane a work piece. Specifically, the motor shaft reducer rotates within a ball-bearing. The distal end of the shaft has an eccentric spindle extension which operates within the ball-bearing put into a slipper. The slipper is formed with arched edges to allow oscillation of the slipper about the centre of a circle which includes the two arcs. Attached to the slipper is a cutting blade which projects through a hole in the sole. The blade has an adjustable cutting depth governed by bolts. When starting the motor the eccentric starts to rotate which causes oscillation of the slipper and, therefore, the blade. Thus, the path traced by the blade during oscillation of the slipper is elliptical.

The deficiencies of the above-mentioned surface treatment tool include friction between its various parts (between slipper and sole; slipper and sole edges; slipper and screw) which causes overheating and wearing; the width of blade is restricted to the width of frame. The blade moves with the slipper within the sole which moves in relation to the frame. If a knot or another harder spot occurs during planing, the slipper begins to lift. To avoid that, it needs to use a stronger (more complex) fixture of the slipper, sole and motor. While planing, the distance of the cutting blade from the front edge of the shavings' slot changes. When the shavings' slot becomes too wide, fibres are lifted and torn from the surface causing thus low quality of the surface. One of the deficiencies is also the big number of various planer parts.

SUMMARY OF THE INVENTION

The purpose of this invention lies in developing an electrical hand planer that differs from the already known solutions and does not have the aforementioned deficiencies. The planer, more specifically the electrical hand planer is suitable both for amateurs/handicraft enthusiasts and industrial use, enabling easy and convenient processing of different wood surfaces. Unlike the already existing solutions, the construction of the planer according to this invention enables the use of a hard alloy blade, resulting in an increased lifetime of the blade. Even when used at a high speed, the blade does not cut into wood. The planed wood fibres remain intact, there are no traces of plane processing and the wood surface is smooth. Thus, the wood surface no longer requires pre-polishing prior to applying paint or lacquer layer.

The blade of the planer according to this invention moves in the manner that the trajectory of the blade points forms a closed curve in the shape of an ellipse. Such blade points' trajectory is achieved by an eccentric attached to the shaft of the planer motor. The eccentric is attached to the planer sole and the blade is attached to the eccentric. Depending on how the blade is attached to the sole, the planer can be used for processing, for instance, a board profile or for cutting chips or veneer sheets of even thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiment of the invention is hereby described with reference to the accompanying drawings, which represent the following:

Figure 1 - planer sole top view. Figure 2 - planer base cross-section along line A-A shown in Figure 1 when the blade is in the lower position.

Figure 3 - planer cross-section with motor.

Figure 4 - increased-size cross-section of eccentric shown in Figure 3 and eccentricity e. Figure 5 - planer base cross-section along line A-A shown in Figure 1 when the blade is in the upper position.

Figure 6 - planer base cross-section along line A-A shown in Figure 2 according to third embodiment.

Figure 7 - planer top view according to fourth embodiment. Figure 8 - increased-size cross-section of fourth embodiment shown in Figure 7.

PREFERRED EMBODIMENT

The electrical hand planer comprises a sole 1 , a motor housing lower part 2 that rests with sleeves 3 on the rear part of the sole 1. The sleeves 3 can be made of either an elastic or rigid material and consist, for instance, of two parts so that the axis of one part is shifted in relation to the other one. The fixing base 4 is connected with the rear part of the sole 1 by fixing elements (such as screws or nuts) 5; the bearing 6 is attached to the fixing base. Through the aperture 7 in the sole 1 , the eccentric 8 is attached to the inner ring of the bearing 6 in the fixing base 4. With the aid of the motor shaft 9, the eccentric 8 is attached to the bearing 10 in the motor housing recess.

According to the first embodiment of this invention, there is a slot 11 in the first part of the sole 1 , the blade 12 is attached to the slot's lower edge into the sole 1 from the underside with a fixing element 13. The blade 12 angle regulation element 14 is attached to the top of the sole 1. According to the second embodiment sample of this invention, the blade 12 is attached to the sole 1 from the top; more specifically, the blade 12 is attached to the upper edge of the slot 11 in the sole 1 with the aid of the blade 12 fixing plate 15 and the blade 12 angle regulation element 14. The cutting angle of the blade 12 ranges between 0-90° whereby the blade 12 is set at 0° towards cutting direction and the blade 12 is set at 90° perpendicularly to cutting direction. When the blade 12 is set towards cutting direction, the first part of the sole 1 before the slot 11 is thinner. The rear part of the sole 1 is covered with a motor housing 16 which has an attached grip 17.

When the motor is started, the bearing 10 begins rotating and with the aid of the motor shaft 9 the bearing 10 causes the eccentric 8 to begin rotating as well. Thus, the eccentric 8 creates an eccentric movement of the sole 1 and thereby the blade 12 also moves eccentrically, creating an elliptical movement trajectory of the blade 12 points.

In addition to wood, the planer according to this invention allows other materials to be processed (for instance, stone or metal) by adjusting the cutting angle and the depth of the blade 12 to a suitable position.

The quality of the processed surface can be modified by adjusting the cutting angle of the blade 12. This is necessary when processing wood of varying strength or when the movement speed of the processed material is changed. The cutting angle of the blade 12 is adjusted in such a manner that the higher the required quality of the processed material, the thinner chips are cut by the blade 12. According to the third embodiment sample of this invention, the sole 1 of the electrical hand planer comprises two or more slots 11 , which can be located both in the front and in the back of the sole 1. Every following blade 12 in each of the consecutive slots 11 projects from the lower surface of the sole more than the previous one. The first blade 12 is meant for robust and deeper cutting and the last blade 12 is meant for finishing.

According to the fourth embodiment sample of this invention, the sides of the sole 1 are upturned 18, whereby the slot 11 and the blade 12 are constructed in the whole width of the sole 1. Such solution allows interior angles to be planed with both sides.

Claims

Patent claims

1. An electrical hand planer comprising a sole (1), a motor housing lower part (2), sleeves (3), an eccentric (8) attached to the inner ring of a bearing (6) in a fixing base (4), a motor shaft (9), a motor bearing (10), a blade (12) attached to a slot (11) of the sole (1), a fixing element (13), an angle regulation element (14) of the blade (12), a fixing plate (15) of the blade (12), a motor housing (16), and a handle (17) is characterised in that the sole (1) is attached to the motor shaft (9) with the aid of a bearing (6) and an eccentric (8) and that the blade (12) is attached to the sole (1) rigidly.

2. The electrical hand planer according to claim 1 is characterised in that while the planer functions, the blade (12) moves with the sole (1).

3. The electrical hand planer according to claim 2 is characterised in that while the planer functions, the distance of the cutting edge of the blade (12) from the front edge of the slot (11) is constant.

4. The electrical hand planer according to claim 3 is characterised in that the sole (1) comprises at least two slots (11), whereby every following blade (12) in each of the consecutive slots (11) projects from the lower surface of the slot more than the previous one.

5. The electrical hand planer according to claim 1 to 4 is characterised in that the blade (12) is attached to the sole (1) from the underside.

6. The electrical hand planer according to claim 1 to 4 is characterised in that the blade (12) is attached to the sole (1) from the top.

7. The electrical hand planer according to claim 5 or 6 is characterised in that the cutting angle of the blade (12) ranges between 0-90°, whereby the blade (12) is set at 0° towards cutting direction and the blade (12) is set at 90° perpendicularly to cutting direction.

8. The electrical hand planer according to claim 7 is characterised in that the front part of the sole (1) before the slot (11) is thinner.

9. The electrical hand planer according to claim 3, 4, or 7 is characterised in that the width of the slot (11) and the blade (12) are constructed in the whole width of the sole (1).