EP0878280B1

EP0878280B1 - Electro-manual smoothing planer

Info

Publication number: EP0878280B1
Application number: EP98108380A
Authority: EP
Inventors: Ezio Trevisiol
Original assignee: Individual
Current assignee: Trevisiol Ezio
Priority date: 1997-05-12
Filing date: 1998-05-08
Publication date: 2006-11-15
Anticipated expiration: 2018-05-08
Also published as: EP0878280A3; DE69836397D1; EP0878280A2; ITTV970063A1; IT1293358B1; DE69836397T2; ES2276438T3; ATE345203T1; ITTV970063A0

Abstract

Portable electro-manual smoothing planer, of the type in which it comprises: two planes for the resting on the surface to be worked (3, 4) of which: a fixed rear resting plane (3) and a movable (1) front (4) resting plane, at least retracted respect to the plane of the first one (3); a tool-holder operating roll (13), placed between said two planes (3, 4), rotatably motorised on horizontal axis transversal respect to the advancement direction by manual thrust of said portable electro-manual smoothing machine (20-19, 9, 16, 8, 7), operator on the surface to be worked, with operating surface substantially around said fixed rear plane (4) a first control main handgrip (2) above said rear resting plane; operation electric control means (12) on said control handgrip (2); a second substantially knob-shaped handgrip (1), above said front resting plane (4), rotatably operable manually, for rotating axial means with resting screw to said front resting plane for lifting or lowering it respect to said rear resting plane (3), characterised in that said tool-holder operating roll (13) is structured for housing in it at least an abrasive coating (22). <IMAGE>

Description

Object of the invention

The present invention concerns a portable electro-manual smoothing planer according to the preamble of claim 1.

Prior art

An example of such a planer is disclosed by US-A-4 363 343.
In the handicraft activity of wind-surf manufacturing the most important and engaging step is that of obtaining the shape of what will be the surf inner form. This surf for weight reasons is obtained from the manufacturing of low density foam polystyrene blocks. For this purpose the commonly used tool is the electric planer.
The essential elements of the present portable electric planer remain: the resting planes and the blade-holder roll endowed with knives which by its vertical revolving action carries out a removal of the wood, still in chips. Nowadays, just like in old times, the action remains a cutting one carried out by blades or chisels.
If all this is perfectly functional and consistent with the wood working, given its specifical density and consistency, it meets some limits in the working of other materials.
As previously stated the material which is interesting to work by using the electric planer is the foam polystyrene or other similar foam plastic material, having a low density and a poor consistency.
It is clear that on a material having such characteristics said planer blades, also known as jack plane, were not able, to carry out the desired cutting action, but instead tended to strip and disjoin irregularly the worked material in small pieces giving a poorly finished and rough product.

Purpose of the invention

Purpose of the invention is solving this problem by obviating the above mentioned drawbacks.

Disclosure of the invention

The problem is solved as in the enclosed claims.
The innovative and original potential al of this is tool became even more clear. Such an extraordinary abrasive capacity in fact could only depend on the very high number of revolutions and consequent peripheral speed of the smoothing roll normally not common to other tools used for the smoothing; in fact, the roll by making a rotation of 15.000 revolutions a minute produces a peripheral speed higher than 150 km a hour and just one abrasive particle touches the material to be removed by orbiting 300 times a second. A second essential peculiarity of the abrasive roll action of the new tool is that of coming into contact with the material to be removed in a width equal to its advancing face but with a depth and a length of few mm., therefore the contact surface remains very small in any moment of the working. This causes an absolutely prevailing condition of the abrasive great power with regard to the treated material and avoids also overheating and melting due to friction. Another winning factor, as said, lies in the capacity of the smoothing roll of maintaining itself constantly clean and this is due to the centrifugal force to which the material is subjected once it is removed and then eliminated through the dust discharging channel also guaranteeing an exceptional cleanness on the working area.
This great power and effectiveness though, would not be easy to manage if the roll position and the action depth of the same were not determined and controlled by the rest of the tool structure which being in direct contact with the material to be treated provides such a function.
These characteristics, this abrasive power surplus, together with the action easy handling and control given by the tool resting plane, distinguish the new tool from all other available tools, making it able to carry out works which before were not satisfied.
Considered the needs and reasons which brought to the creation of the new tool, explained its characteristics and possibilities of usage, a more specially descriptive analysis of this tool and of its essential parts will be now carried out.

Description of a preferred form of the invention

The invention is described with the aid of the enclosed tables showing one of the possible preferred forms of embodiment, where:

Fig. 1 (Tab. 1) represents a side view on the side of the material discharge of the new tool;
Fig. 2 (Tab. 2) represents a side view of the tool on the opposite side;
Fig. 3 (Tab.3) represents a bottom view, that is on the resting side of the tool on the surface to be smoothed;
Fig.s 4 and 5 (Tab. 4) represent a side and a top view of the abrasive tubular ring intended to be inserted in interchangeable way on the supporting cylindrical roll.
Figures 6 and 7 (Tab. 4) represent a side and a top view of the tubular abrasive supporting cylindrical roll.
Fig. 8 (Tab. 4) represents the view of the tool intended to extract the abrasive from said roll.

Preferentially, this tool should preferably be light and compact for easing the handling (length 30-65 cm. - width and height about 15 cm.).
The machine frame or supporting body will be made up of two shells (6 , 5) in plastic material joined along the middle longitudinal line of the tool by self-threading screws.
Such shells will determine the same machine aesthetical shape and will have to support, contain and join all the manufacturing details. Both motor (19) and smoothing roll (13) are housed inside of the shells transversally respect to the tool's longitudinal axis, both rest by means of pins on the relative bearings which in turn have their seat on the frame walls. Except for the bearing opposite to the roll transmission side which for practical reasons may be contained by the same roll or, in alternative, by the access flange (14) to the roll, also present on the side opposite to that of transmission. The motors used in the tested prototypes had rather low power such as 300 and 500 watt and allowed roll speeds respectively of 17.000 revolutions a minute for the first one, and 14.500 revolutions a minute for the second one. In the first case the abrasive roll had a diameter of 3,5 cm., in the second case of 5 cm. The motors anyway in no case showed any kind of lacks or problems resulting very suitable for the use.
The two respectively resting and sliding planes are fixed to the shells: the fixed rear one (3) and the movable front one (4) The second one moves in height at a certain extent. The front handgrip, knob-like shaped, (1) may further have the function of carrying out by a joining screw (18) the lifting or lowering of said front resting plane also known as tool front resting plane.
The external carter on the left side (6) contains and protects the transmission pulleys (7, 9) respectively fixed in the roll and motor pins, protruding from the shell. The motor pulley has a diameter of about half the roll's. The coupling and transmission will be ensured by a toothed belt (8). In the right part the carter (21) covers and gives access to the motor main bearing and besides allows to carry out the brushes replacement (20) of the same. Always on the motor axis and inside of the frame shells on the left part a small turbine (16) is arranged, having a double function: the first one, of cooling the same motor sucking air from the slits placed on the right shell bottom and on the right carter (21); the second one of convoying and easing, by means of a channel (10), the dust downflow from the suitable discharging channel (11). In an advantageous solution the smoothing planer comprises the roll (13) interchangeable with a roll having cutting blades or with a roll having an abrasive surface (13, 22).
Thus a universal planer able to operate with both tools is obtained.
A particular roll shape for receiving alternatively either the cutting blade or the abrasive coating, with a normal design solution may be provided.
A typical and necessary detail of the new tool, found on the right side in correspondence of the smoothing roll seat is the flange or removable carter (14) which allows an easy access to the roll for replacing the abrasive material.
Said flange will preferably be of metal material requiring a good stiffness, will support the right bearing which in turn will house the roll pin or support a pin in case the bearing was included on the roll itself. A series of holes along its perimeter in correspondence of threaded pins fixed on the frame (15) of the smoothing planer which will ease its fixing by means of self-locking bolts or fixing ring nut and the centring respect to the roll axis is provided. Once closed, the flange hermetically matches with the shell for avoiding the dusts coming out from possible slits during the working. Inside of the shell, in the smoothing planer front part the suitable guides will be obtained which allow the vertical movement of the front resting plane (4) which, as known, will have to be lifted or lowered controlled by the front handgrip or by any other mechanism provided. The material which makes up the front resting plane (4) is aluminium. The machine rear handgrip (2) contains the electrical or electronical switch (12) and is made up of the same extension of the two shells forming the bearing frame. For handling reasons it would be desirable if this handgrip had an inclination of about 45° respect to the sliding planes.
The rear wall of the smoothing roll seat obtained inside of the shell (27) follows the shape of this same at a distance between about 3-5 mm, the front part (28) starting at the same distance from the roll in the contact point with the front resting plane it is progressively spaced for creating the exit channel (17) and the necessary hollow for the dust discharge, a typical functional scheme of the centrifugal fans. The dust discharging channel (17-11) is commonly placed above the smoothing roll and its exit hole may be located in the most suitable position, in the specific and suitable case, the lateral one. The smoothing roll (13) is with no doubt the essential most important and typical member of the smoothing planer, that is the part which combined with the other ones gives the innovative and special performances which distinguish this tool for effectiveness and purpose of usage. As stated, it is placed transversal to the smoothing planer longitudinal axis and its lower part is tangent to the plane formed by the two sliding planes (3 - 4) when placed in their rest position. The front resting plane being drawn into the shelf will determine the smoothing and removal depth. (from 0-5 mm.).
The roll will meet the material to be worked by rotating in opposite direction respect to the tool advancement direction.
The roll (13) will have in particular the ability to support the abrasive (22) which will be interplaced on the same, both in case of wear, and if a change of the grain or quality is desired.
For allowing this interchangeability the abrasive will therefore be shaped like sleeves (22) which will be inserted over the smoothing rotating cylinder (13).
The essential characteristics for the abrasive-holder roll when in working position on the roll (13) are:

1) the absolute balancing for avoiding any kind of vibration;
2) the shape which shall remain stable and unchanged both with a low and with a high revolutions number;
3) the weight which shall guarantee a certain inertia:;
4) the centring;
5) the outer surface which shall be the most stiff as possible without feeling the effects of the outer pressures.

These details have a direct influence both on the abrasive life and resistance and on the final work result for which the tool is thought.
In fact, during the tests it was noticed that the abrasive (22) had some irregular spaces only in the areas in which it could move and in which it was not supported firmly, enough by the roll (13); the problem was not to be ascribable to rubbing wear, but rather to the continuous bending movement to which the abrasive and its canvassed support were subjected, given the tool's high number of revolutions. Furthermore, it was considered that an important characteristic of the new smoothing planer was that of working on materials of different hardness matched one with the other without enhancing the differences, and its is understandable that, if the abrasive roll surface was not stiff, it would feel the effects of the pressure differences which the various materials would cause during the working thus limiting the abrasive life as above mentioned and not guaranteeing that planarity and finishing likeness which the tool may supply.
For the roll (13) manufacturing, metal materials such as aluminium and steel which may supply the needed requisites and guarantee a better heat absorption and dissipation will be therefore preferable.
The abrasive spares will be shaped as sleeves (22) with a length equal to the one of the roll which will support them (13) and shall have such a stiffness that will allow them to be inserted on it with a certain pressure without bending or becoming flabby. It is important that between roll and sleeve there is the least possible tolerance being though able to guarantee the insertion and extraction of this latter by a thrust of about 10 kg. This for guaranteeing the maximum integration and functionality between the two elements.
The tested sleeves prototypes are made up of some fibreglass layers impregnated with epoxidic resin on which later some strong abrasive canvas with a grain of 60 was fixed. Thus I obtained some tubes having a thickness of about one millimetre (but we could use also higher thicknesses), which once inserted in the abrasive-holder roll will be integral with it guaranteeing regularity and homogeneity of yield. On the sleeves internal surface two small protrusions (25) or guides in diametrically opposed position may be provided and will have the function of avoiding the rotation between roll and sleeve.
Two fissures (26) in a corresponding position are provided on the roll having both the function of housing the sleeve guides, and of allowing the extraction of this latter by using a simple extractor (24). In fact, if for the sleeve insertion on the roll a certain pressure will be necessary, anyway easily exertable from the outside, for the extraction, unless the whole roll is provided to be removed from the machine, there would not be enough grips and hold for exerting an equal pressure in the opposite direction. I therefore provided a simple and economical accessory which will allow to easily remove the sleeve from the roll. The extractor (24) will be made up of a steel fork at whose outwards turned ends there will be two small protrusions (fins).
By using the fissures (26) provided in the roll, the extractor will penetrate up to its base and hook the sleeve on the lower edge by the fins. Gripping the fork with two fingers and laying the hand palm on a small counter-thrust small rod (23) directed against the roll in the pin area, by an easy traction it will be possible to extract the sleeve without an excessive effort. This operation together with that of opening and closing the pin holder flange (14) of the roll by acting on the suitable bolts or spring ring nut will be the actions necessary to replace the abrasive, even if this possibility is not as frequent as in other types of smoothing machine.
Summarising we can say that the new smoothing planer, a tool created for solving single problems, in view of the facts has shown many abilities and absolutely innovative peculiarities. It is able to carry out working functions for which before there were no answers and it may be used in many both professional and hobby fields.
Its action can be graded with precision and may have both a strong impact and a finishing ability.
The materials to be worked are the most different ones and they may be treated also when coupled and with different or opposite characteristics.
It may work on a free field, that is being displaced on the worked product without being forced to be stationary.
The new smoothing planer offers optimal solutions for the planes grinding; for the joining of wide radius curved lines; for low density materials working; for fibrous and strong materials working; for removing surfacing or protrusions from flat surfaces also in very soft materials without touching or marking them; it is ideal for plastic laminates where chipping must be avoided; for fibreglass or the like; for wood when small shape corrections are necessary. It has a good working economy and use facility which make it suitable for any user.

Claims

Portable electro-manual smoothing planer which comprises:
two planes for resting on the surface to be worked (3, 4) of which,
a fixed rear resting plane (3) and
a movable front (4) resting plane, at least retracted with respect to the plane of the first one (3);
a tool-holder operating roll (13), placed between said two planes (3, 4), revolving motorised on horizontal axis transversal with respect to the advancement direction by manual thrust of said portable electro-manual smoothing planer by an operator on the surface to be worked, with an operating surface substantially around said fixed rear plane (4);
a first control main handgrip (2) above said fixed rear resting plane (3);
operation electric control means (12) on said control main handgrip (2);
a second substantially knob-shaped handgrip (1) above said front resting plane (4) and revolving operable manually, for rotating axial means with resting screw to said front resting plane (4) for lifting or lowering it respect to said rear resting plane (3); characterised by
the tool-holder operating roll (13) structured for receiving on it an abrasive tube (22), said tool-holder operating roll (13) being accessible on one side, by removing a flange (14), for the axial extraction and insertion of said abrasive tube, which will meet the material to be worked by rotating in the opposite direction with respect to the tool advancement direction, the tool holder-roll (13) having two fissures (26) where an extractor can be put in;
an abrasive tube (22) for mounting on the tool-holder roll (13) with the least possible tolerance being though able to guarantee the insertion and extraction of this latter and;
a fork-like extractor (24) with ends directed outwards and central propping screw with extractor function for extracting said abrasive tube (22) from said toll-holder roll (13) when mounted thereon by inserting the ends in said fissures (26) provided in the tool-holder operating roll (13) such that the extractor will penetrate and hook the abrasive tube (22) on the lower edge by the outwardly directed ends.
Smoothing planer according to any of the previous claims, characterised in that said tool-holder roll (13) is operated to rotate at about 15000 revolutions a minute.
Smoothing planer according to any of the previous claims, characterised in that the flange (14) will preferably be of metal material requiring a good stiffness and has a series of holes along its perimeter in correspondence of threaded pins fixed on the frame (15) of the smoothing planer which will ease its fixing by means of self-locking bolts or fixing ring nut and the centring respect to the roll axis is provided.
Smoothing planer according to any of the previous claims, characterised in that it is integrated with the fork-like extractor (24), the extractor (24) being made up of a steel fork.