US3722563A

US3722563A - Method of mass-producing skis and an apparatus therefor

Info

Publication number: US3722563A
Application number: US00131696A
Authority: US
Inventors: E Schober
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-06
Filing date: 1971-04-06
Publication date: 1973-03-27
Anticipated expiration: 1990-03-27

Abstract

The instant invention relates to an improved automated method of mass-production of skis which are mainly wooden in construction and an apparatus therefor. The method uses planks of wood cut from timber in such a way that the longitudinal surface of the planks is substantially parallel to the course of the wood grains thereby utilizing to the best advantage the inherent fibrous property of wood. The method further comprises combining and dividing said planks into blocks and subsequently sheets of required sizes for the construction of skis. Sheets so procured are next preheated and an adhesive applied thereto to form sheet packs; the sheet packs are transferred to a press machine wherein as the packs travel they are continuously subjected to a high pressure, at the same time applying further heat where necessary. The sheet packages emerging are transferred next to a machine where the required operations such as planing, selective edge trimming by milling, and grinding are performed by a group of tools to produce raw-skis; the raw-skis are then painted, screen printed and varnished in an automatic machine wherein there may be infrared-ray drying. The preliminary drying and further drying of planks and sheet packs respectively are preferably by means of electrical resistance heating. The process provides a very fast, efficient, automatic and economical method of mass-production of skis.

Description

United States Patent 1 Schober [54] METHOD OF MASS-PRODUCING SKIS AND AN APPARATUS THEREFOR [76] Inventor: Engelbert Schober, Bannholzstrasse 302, Vaduz Liechtenstein, Austria [22] Filed: Apr. 6, 1971 [21] Appl. No.: 131,696

[52] U.S. Cl. ..144/3l7, 144/3, 156/254 [51] Int. Cl. ..B27d 3/00 [58] Field of Search..l44/l, 2, 3,144, 309, 313-319;

[56] References Cited UNlTEDSTATES PATENTS 3,461,932 8/1969 Shelton et al ..l44/3l7 3,199,555 8/1965 Hildebrand ..l44/3 2,301,339 11/1942 Smith et al. ..l44/317 2,213,903 9/1940 Davidson ..144/309 Primary ExaminerAndrew R. Juhasz Assistant Examiner-W. Donald Bray Att0rneyl-l0lman & Stern [57] ABSTRACT The instant invention relates to an improved auto- 1 Mar. 27, 1973 mated method of mass-production of skis which are mainly wooden in construction and an apparatus therefor. The method uses planks of wood cut from timber in such a way that the longitudinal surface of the planks is substantially parallel to the course of the wood grains thereby utilizing to the best advantage the inherent fibrous property of wood, The method further comprises combining and dividing said p1anks into blocks and subsequently sheets of required sizes for the construction of skis. Sheets so procured are next preheated and an adhesive applied thereto to form sheet packs; the sheet packs are transferred to a press machine wherein as the packs travel they are continuously subjected to a high pressure, at the same time applying further heat where necessary. The sheet packages emerging are transferred next to a machine where the required operations such as planing, selective edge trimming by milling, and grinding'are performed by a group of tools to produce raw-skis; the raw-skis are then painted, screen printed and varnished in an automatic machine wherein there may be infrared-ray drying. The preliminary drying and further drying of p1anks and sheet packs respectively are preferably by means of electrical resistance heating. The process provides a very fast, efficient, automatic and economical method of mass-production of skis.

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SHEET 8 [IF 8 FIG] IN V EN TOR METHOD OF MASS-PRODUCING SKIS AND AN APPARATUS THEREFOR BACKGROUND OF THE INVENTION one single or a multitude of parts which are placed on top of each other and side-by-side.

The latest skis are made either entirely of wood, for instance of Ash, Birch, or Hickory, either as a solid piece or laminated, or they are manufactured as combination-layered skis, of wood combined with metal or with synthetic materials giving the so-called combination-construction. Multi-layered or laminated skis have outstanding firmness characteristics and are technically very good. It has however been proven that the use of wood as a raw material in the manufacture of skis, cannot be ignored. Especially in the ski'core which is subjected to a high degree of longitudinal stress reversals, wood is far more superior, if applied properly, compared to thermosetting or thermoplastic raw materials.

The instant invention permits skis to be effectively designed so that they are simple in construction and thereby inexpensive to manufacture, utilizing the lowest possible amount of material and manpower, and still have the best usage characteristics and high resistance.

DESCRIPTION OF PRIOR ART A type of wood-sheet is used for the manufacturing of wooden skis, multi-layered or combination skis, whose manufacture does not consider the wooden structure, the wood-grain, or the course of the wood rings. Ski planks are manufactured out of round timber by sawing the timber axially to the trunk with the aid of a gangsaw or a bandsaw into prisms, boards, or planks and further separating them with a band or a circular saw. Since, however, a round timber trunk has a round conical and not a cylindrical shape, the cuts are always made through the course of the wood fiber. This removes from the wood one of its most outstanding characteristics, namely, its buckling strength and bending flexibility.

SUMMARY OF THE INVENTION The instant inventive method does not use the prior art cutting methods and machine construction, since the wood used, though slightly tapering is to be axially arranged to be parallelly cut and trimmed in accordance with the present invention.

A further important feature of the present invention is the manufacturing of skis planks in the so-called tan- I gential cut, i.e., in a way so that the course of the wood The transfer of planks from one machine to another can also be made by a fully automated process, without the need for manual intervention.

The glueing of the ski planks into blocks and the dividing of these blocks into ski sheets is made by means of prior art machines, improved with interlinking conveyor means according to the most modern state of technology in order to obtain a fully mechanized or automated working process.

The greatest amount of work is required in the assembling, lacquering and finishing steps of the skis. Many methods have been tried and have been found effective, however, in all cases, skis were manufactured by way of separate distinct processes. Furthermore, even where many process steps were linked together, only a partial automation has ever been obtained. Also, because the different steps take different time durations there must be buffer zones or storage zones between the different steps to maintain the processsequence. There also exist on the market, processing machines which permit only one individual working sequence, at best only a single working cycle process in contrast to the apparatus of the present invention.

The inventive method and apparatus permits, however, a continuous flow of work and brings to realization an industrious and efficient production, whose advantages are evident, and the invention permits maximum yields under optimum exploitation of materials and time, avoiding the extensive tie-up of capital brought about by the buffer zones in the dispersal, drying, and storage areas where half-finished skis are just standing or laying around, awaiting the next process step.

An important characteristic of the invention is its continuous uninterrupted flow of processes of the workpieces, regardless of how much of a varying working time is required for the individual work phases. Varying working periods are balanced out by a varying number of processing machines and installations.

A further important characteristic is the possibility of accomplishing a working step during the conveying by means of new devices. The workpiece is in continuous movement and the transportation means serve during the treatment at the same time as holding devices for storing a plurality of workpieces.

The inventive method precludes the requirement for padding or interstratification also in that through a standardization of the measurements of the workpieces,-a minimum or treatment is required.

The inventive process enables the preparation of the individual sheets, regardless of whether these are utilized later as bottom sheets or as upper sheets in the skis. A great part of the processing may conveniently be made on the standard individual sheet, including the entire priming and pre-varnishing work.

In skis, a complicated application of varnish, also even a repeated coating of varnish, should be considered, and invariably long drying periods are needed, and this required that hitherto skis had to be placed on rack-carts in order to be moved manually through drying channels. These rack-carts have, however, the disadvantage that they require repeated manual handling. Each interim varnishing requires that the skis be received and transferred manually.

The inventive method is based on that a part of the varnishing of the skis, namely, the surface priming and application of lacquer-paint can be made prior to completion of the process on the still flat and light skisheet. The sheets are thus especially suitable for automatic processing; also grinding work can be done between moving the skis through the drying channel and the repeated application of varnish.

The instant method and apparatus achieves these objects to a great extent in that the trunk, or the wood to be cut, is always separated from the outside towards the center and the cuts are always parallel to the course of the wood fibers. Through this method, the best and purest sapwood is utilized whereby a residual wedge of the less suitable core of the wood remains as waste.

This qualitative and also quantitative advantage is obtained by specially assembling two single-blade machines, which may either be a bandsaw or a circular saw. These two machines are opposed to each other, i.e., the two machines are working cooperatively as one machine-unit but they work in a counter-rotating manner. By this arrangement, the shortest path for the workpiece and optimum cutting performance is obtained.

- BRIEF DESCRIPTION OF THE DRAWINGS In order to better illustrate the instant invention, reference is made to the accompanying drawings, in which:

FIG. 1 is a schematic of the machine for making ski planks; 1

FIG. 2 is a schematic of the preheater unit for heating sheets of wood and applying glue;

FIG. 3 is a schematic of a press-machine wherein packs of wood are continuously compressed and selectively heated;

FIG. 3A is a cross-sectional view of the pressmachine of FIG. 3;

FIGS. 4 and 5 illustrate a schematic for automated machining, profiling and grinding machine for machining skis;

FIG. 6 is a schem atic of a varnish drying unit;

FIG. 7 is a schematic of a ski-handling device used in the method of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Prisms, planks or board-cuttings are conveyed over the longitudinal conveyor 1 and can be stopped by way of a collar or stop means 1" and then be transferred to the transverse conveyor 2' by means of an ejector 1". The transverse conveyor brings the wood to be cut to the supply table 2". This is the input point for the processing machine 5. The planks are selectively moved across the conveyor 3 to the transverse conveyor 8" and thence to the supply table 8" of a processing machine 10 which is oppositely positioned the processing machine 5.

Both processing machines 5, 10 function in counterrotating manner and have splinter traps 6, 11 coupled to them. At this point, waste material in the form of splintors isseparated from the wood being cut. Since the two devices for trapping the'splinters are positioned side by side, the entire waste material is transferred to a transverse conveyor 14 which transfers this waste to a next stage for further utilization. The ski planks produced by machine 5 reach a conveyor belt 7 by means of a special lifting device of the splinter trap 6 and are then moved directly. The ski planks produced by machine 10 reach a conveyor band l2 by a special lifting device of the splinter trap 1 l, and by means of an ejector slide 12'' are moved onto a conveyor band 15 to be moved to a further manufacturing processing point.

Since a ski plank is separated only with the use of one single-blade machine, the remaining section of the prism, plank or board, is moved always to the opposite processing machine, e.g. from processing machine 5 over the splinter trap 6 and the transverse conveyor 8 to the supply table 8". From here, the wood moves through the processing machine 10, the splinter trap 1 I and a transverse conveyor 13, to a supply table 13''.

This cycle is continued until the wood is cut up completely into ski planks. The elements 4 and 9 represent variable stops at the processing machines, which enable the squaring of fixed widths.

Described hereinbelow is an exemplary inventive method for the processes of assembling, varnishing and finishing of wooden skis and explained with reference to the accompanying drawings which relate to the inventive equipment and method. The wooden sheets, produced in accordance with the method described in brief earlier, have uniform crosscuts, but they can be identified as a bottom sole or a wedge board only through their varying length-measurements. These variously long wooden sheets are as seen in FIG. 2 separately layered into three collection containers 201 which are stacked above each other, and are offset sideways. From here, an ingenious mechanical device 202 takes over the transportation and moves the sheets via heating plates 203, in order to heat said sheets to a predetermined temperature. This is accomplished after they have moved over the heating plates, sheet after sheet in three or more levels they are then transferred to a longitudinal conveyor 204 which moves the sheets through a glue-applying device. Glue is applied on both sides of the sheets which are placed on top of each other at the end of the conveying track, where they are compressed.

The resulting rectangular sheet-package after being straightened by mechanical means is then inserted sideways automatically into a gripping device of a press passage. An exemplary illustration of this inventive device is shown in FIGS. 3 and 3A and is described hereinbelow. The devices 308 receive continuously one or more of the sheet packages, and centers as well as spaces them and moves them continuously, under high pressure, through the press-passage, either with or without the heat effects.

- At the end of this step, the gripping devices open up and a mechanical transfer device pushes and centers the glued sheet-package or even a plurality of packages into a further, parallelly placed, gripping device. This latter gripping device is so designed that the planing of the wedge-form can be made during the continued transport in the wedge-planing machine.

This gripping device the same time functions as a continuously moving conveyor and feeds the work- 1 piece to a planer 406 which, according to a respective master pattern, forms a wedge-shape. A schematic illustration of this device is provided in FIGS. 4 and 5. Principally, all processing machines of the invention are equipped with the identical workpiece transportation means 403; only the ski mountings $01 and the gripping-levers 408 vary according to their application or the attached processing tools 406.

After the wedge-shaping on the raw ski has been made, the ski is then ejected from the gripping device whereby at the same time a surface sheet, which a short time earlier has been glued on its underside, is simultaneously placed on top of the raw ski. Since the raw ski and the surface sheet have identical dimensions in regard to length and width, it is possible for a centering and inserting machine to insert this flat and rectangular sheet-package automatically into a gripping/press/heating-device of a press machine passage.

The press machine has forms which grip at first an end of the entire sheet-package and form the flat sheetpackage into a molded ski. Pressure and effects of the heat applied by means of the electrical resistance heating in the required glue-adhesion time give the molded ski its strength and form. Since up to this point the ski, viewed from the top, has still its rectangular shape, assembling devices are unnecessary.

FIGS. 3 and 3A provide an illustration of the schematic structure of this press machine which comprises a frame 301, two variable pressureand glide-tracks 302 and three roller-conveyors; and press-forms or forming units 308 for two skis each in a plurality of sets, which are guided on a dual-stranded roller-chain train 306 continuously through the press machine. The

required heating is provided by electric heating.

The movement of the wood-sheet packages through the pressing machine is made, for constructive and economical reasons, mostly in a forward move in the lower section, and returned in the upper section as a two-level press. With this arrangement, the entire length of the course is reduced by one half of the otherwise necessary length of the pressing process. The pressing length depends on the required pressing performance and the binding time of the glue.

At the front end of the upper section of the press, the lower part of the form separates from the upper part of the form and the two molded skis are automatically ejected and transferred to the next conveyor device.

The continued transport of the molded skis is made by way of a longitudinal conveyor for passing through the automatic profiling and grinding machine. FIGS. 4 and 5 provide a schematic illustration of the processing and transporting system of this machine.

One molded ski after another is placed into the transportation-gripping devices 403 of this machine via an inserting and centering device. These gripping devices are guided by two roller chain tracks 402 which run continuously through the profiling and grinding machine. They are loaded from the right frontal side of the device and are again unloaded at the left end of the device. Each gripping device carries its own profiling templets. All processing tools 406 which are required for the profiling of the skis are mounted double-sided in the machine. A multitude of milling tools for the coarseand fine-milling work as well as those which are double-sidedly mounted and those which function from the top and continuous sanding belts give the raw ski its side-shape, whereby the tips and the ends of the ski are simultaneously profiled in one stage.

After completion of this processing phase, the gripping devices of the continuous grooving and glidesole sanding machine accept then the molded, sideprofiled, ski whose upper side has already been finished, and the sole-groove and finishing of the underside of the sole is next made in one single process.

Since each further machine passage is constructed in the same manner, a further detailed description is unnecessary. it should however be mentioned that a steeledge slot-cutter is necessary in the continuous-surfacegrinding device in case the skis are supplied with steel edges. Naturally, coupled thereto must be the steeledge mounting machine and a continuous steel-edge grinding machine.

With the description of the inventive method has been illustrated the manner of ski construction while the processing phases of varnishing and finishing are remaining.

Since the prior art process of varnishing and finishing of skis differs from the instant inventive method, the further processing phase of the molded ski is in accordance with the instant invention.

In the automatic processing flow, the molded skis are individually moved next into a continuous sprayingand screen-printing machine wherein insignias, letters etc. are placed on the continuously moving ski sideways by means of the spraying and screen-printing method. An infrared ray producing means which is mounted on the machine channel dries rapidly the freshly sprayed-on lacquer so that thereafter the ski can at once be moved through the varnishing machine.

It is also safely possible in the instant invention to move a completely formed ski, after the application of varnish, through a continuous drying-channel. An effective inserting/transporting/transfer-device enables an automatic transportation. Respective guiding elements control and direct the drying process.

From the varnishing apparatus, the formed skis are at once caused to enter the continuous varnish-drying channel. This channel is preferably constructed in a way to allow the varnish to dry on the skis in one single move through the drying chamber. FIG. 6 shows a schematic process in a varnish-dryer. From this drawing can be noted that the skis enter from the lower right section of the dryer and after moving in said dryer in a zigzag fashion through eight levels, they exit then at the upper right section of the dryer. This varnish-dryer comprises a frame 601 with an insulated outer skin, the multi-level transverse conveyors 602, the two transfer devices 603 at the front and rear ends of the channel and the air ventilators.

According to the required quality of the skis, the application of varnish and varnish-drying processes can be repeated often. The transport of the formed skis through the varnish dispenser machine and the dryer channel passage is fully automatic and is automated by means of numerical control.

Thereafter, the varnished ski is then moved to a packing and transporting installation.

in conclusion it may be mentioned that the inventive method, in combination with the utilization of new equipment which is described in more detail herebelow, enables a fully mechanized and, through respective guidanceand control-elements, automated transportation and manufacturing process. in addition to this advantage, the inventive method provides also the advantage of a comparably simple and economical manufacture of skis whereby there is every possibility of producing qualitatively high-grade skis.

The devices which are used for the inventive method are described hereinbelow, the present state of technology being mentioned in brief.

The first inventive device is the preheating chamber of FIG. 2 which is arranged in a multitude of levels, comprising an input-storage 201, a transporting machine 202, the heating plates 203, the longitudinal conveyors 204 and the glue-applying devices. This arrangement has not been known before and features an absolute novelty.

FIGS. 3 and 3A illustrate the inventive two-level pressure machine passage. It comprises of a strong profile steel-frame 301, with one fixed and two variable pressing crossbars 302, the three roller conveyors 303 with leading-chains, the conveyor roller driving and guide-sprocket wheels 304 and the continuously adjustable driving block. A hydraulic system feeds the illustrated hydraulic cylinders 305. Within this press system, the two conveyor chain strands 306 together with the forming units 308 move continuously and perpetually over drivingand returning-wheels 307. Since the two chain strands, displaced by the length of the forming units, are ending or being returned, and the forming units are suspended only at two points diagonally opposite between the two chain strands, the individual forming units moving always horizontally. Each forming unit functions to perform gripping, heating, and transporting. It comprises separate upper and lower form-sections, whereby a stay-bolt 310, or a multitude of the same, connect the two sections at both sides. A pair of hooks 309 serves to solidly connect both sections during the transfer from the lower to the upper level of the press. The forming unit serves for the acceptance of a pair of skis. The lower form section is equipped with a hydraulic padding cushion which, selectively prestressed, adapts itself to the ski to be formed. Both forming sections possess such a heating plate for electric resistance heating. The continuously adjustable, perpetually moving conveyor roller chain moves the forming units, together with the material to be shaped, into the actual forming course. The conveyor chain and the forming units move on hardened steel guides and steel rollers. Through the utilization of these special rollers of the conveyor, which, while perpetually being pulled through a chain strand, are rolling between the pressing crossbar and the forming unit, and, there exists only a rolling friction despite the existing pressure. Such pressing machine passages for manufacturing skis have not been known to exist in prior art practice.

The next inventive device is the profiling and grinding machine passage. FIGS. 4 and 5 provide a preferred embodiment again with limiting the instant invention to this machine. It comprises a processing machine having a continuously moving transporting device, the latter comprising two continuously moving transposedly arranged, chain strands 402. Between these are arranged the transporting'and gripping devices 403 and also these move over the returnand driving-wheels 407 of the conveyor chain, while remaining always in a horizontal position. A gripping device comprises of a frame having a length identical to that of the workpiece, a multitude of holding levers 408 with pull-off roller bearings (not illustrated) and shock-mounted pressure arrangement 409 at the bottom form of the raw ski. The lever and the shock-mounted pressure arrangement press the raw ski symmetrically and firmly onto a bottom form. The guidance rail 404 represents, according to its design, the counter-support for the holding lever. The gripping devices move the raw skis continuously through the processing tools 406 which are driven each by an electric motor 405 over a V-belt drive 515. The scanning roll 514 at the processing tool determines the ski form to be profiled in accordance with the inserted master form pattern 516. In order to obtain a high degree of precision during the working process, each gripping device is guided free of play in the guide bed of the machinery frame 401 by means of

guide rollers

512 and 513 which have ball bearings. It is also possible that a multitude of work tools in the form of milling spindles and endless sanding belts are arranged in the machinery part, whereby they are generally arranged at both sides of the chain train.

This working process in the continuous method by means of a multitude of gripping devices, which are always moved horizontally and in a continuous rotation, has not been known before and features inventive novelty.

A further inventive device is illustrated in FIG. 6 as a multi-level dryer-passage for drying varnish on skis. Based on the necessity for the ski to remain in the dryer for a certain length of time in order to obtain a hardened layer of varnish an extremely slow drying process is necessary. This is obtained by a zigzag course of numerous dual-armed conveyors 602 arranged above one another. For space-saving purposes, the moving of the skis is made in a transverse position and they are, at both ends of the drying passage, moved by and ejectionandlifting-device 603 and 606 shown in the drawing by means of a pneumatic system from the lower transport level to the next higher level. An inserting and pull-out conveyor at the entrance and exit respectively of the drying passage completes the apparatus. Naturally, an air ventilation and heating system is required.

These dryer systems also are unknown in today's ski manufacturing industry and therefore feature inventive novelty since hitherto hurdle-carts of dryer systems are known to be pulled manually through the drying channels.

An inventive arrangement of a ski handling device is shown by FIG. 7. According to this arrangement, ski and raw ski-sheets can be moved automatically either in pairs or in a multitude over a powered roller conveyor 701 transversely over a multitude of multisleeved transverse conveyors 702, vertically upwards or downwards over an elevator 703 with a guide chain section. A roller conveyor section arranged in the transverse conveyor and equipped with a

lift device

706 and 707 is able, according to the movement process, to place a ski for example on the transverse conveyor, or to lift the ski off, and to insert or remove same. The elevator can again balance differences in the elevation, irrespective of whether the skis are to be lifted frontally from a transverse conveyor 702 or they are to be lifted from a roller course 104 alongside, or must be placed thereon. A carefully planned electrical control system is required to facilitate the aforesaid operations. This arrangement of a conveyor means is also inventive and is not known in prior art for the movement of skis during manufacture.

It is due to this inventive method and the application of the described devices in combination with a sensitive electrical control system that an automated massproduction of skis is made possible.

What is claimed is:

1. A method for continuous mass-production of skis which are mainly wooden in construction, comprising the steps of:

. a. forming wood which is used as raw material into planks, whose longitudinal surface is substantially parallel to the course of the wood fibers;

b. combining and dividing said planks into sheets of required size;

0. processing sheets so formed in a preheating chamber on longitudinal conveyors wherein an adhesive is selectively applied on the wood-sheets;

. passing wood-sheets so treated in a press machine where said sheets are continuously compressed while said sheets move in the press machine to form sheet packages composed of a plurality of stacked adhered wood-sheets;

. machining said sheet packages emerging from said press machine in a further machine which performs machining operations including at least one of selective edge trimming, planing and grinding as said sheet packages continuously travel through said further machine to produce raw-skis; and,

f. painting, screen printing and varnishing said rawskis according to a pre-selected pattern in a continuous painting and varnishing machine, to produce finished skis.

2. The method as in claim 1 wherein said adhering in step d" is glueing with a thermosetting adhesive and includes a further step of selective heating as part of step d.

3. The method as in claim 2 wherein said preheating and selective heating are preformed by electrical heatmg.

4. The method as in claim 1 wherein said preheating chamber, press-machine and said painting and varnishing machine are of multilevel type.

5. The method as in claim 1 wherein at least a part of said operations is automated.

6. An apparatus for mass-production of skis which are mainly wooden in construction comprising:

a. means for forming wood required for the skis into planks whose longitudinal surface is substantially parallel to the course of the wood fibers;

b. means to combine and divide said planks into sheets of required size;

a pre-heating elongated chamber wherein said sheets are continuously conveyed and are treated with an adhesive;

. a press-machine with conveyors and a constrained elongated passage with means to apply compression forces on a workpiece such as a wood-sheetstack which is placed in said passage and is continuously conveyed, the press-machine including controllable heating means; a machining device which performs operations including at least one of milling, trimminguplaning and grinding on a workpiece such as a sat sheetstack in continuous conveying motion;

f. and an automated device which can do at least one of the operations of painting, screen printing and varnishing.

7. The apparatus as in claim 6 wherein said heating in steps c and d are electric resistance heating.

8. The apparatus as in claim 6 wherein at least one of the devices, i.e. preheating chamber, press-machine and thedevice as in f is of a multi-level type. I

9. The apparatus as in claim 7 wherein said device as in f performs painting, screen printing and varnishing, and wherein this device and said preheating chamber and press-machine are each of a multi-level type.

10. The apparatus as in claim 9 which further comprises infra-red-ray heating-means incorporated in said device which can perform at least one of painting, screen printing and varnishing.

1 1. The apparatus as in claim 10 wherein at least part of the equipment is adapted for being programmed.

1* i t t I

Claims

1. A method for continuous mass-production of skis which are mainly wooden in construction, comprising the steps of: a. forming wood which is used as raw material into planks, whose longitudinal surface is substantially parallel to the course of the wood fibers; b. combining and dividing said planks into sheets of required size; c. processing sheets so formed in a preheating chamber on longitudinal conveyors wherein an adhesive is selectively applied on the wood-sheets; d. passing wood-sheets so treated in a press machine where said sheets are continuously compressed while said sheets move in the press machine to form sheet packages composed of a plurality of stacked adhered wood-sheets; e. machining said sheet packages emerging from said press machine in a further machine which performs machining operations including at least one of selective edge trimming, planing and grinding as said sheet packages continuously travel through said further machine to produce raw-skis; and, f. painting, screen printing and varnishing said raw-skis according to a pre-selected pattern in a continuous painting and varnishing machine, to produce finished skis.

2. The method as in claim 1 wherein said adhering in step ''''d'''' is glueing with a thermosetting adhesive and includes a further step of selective heating as part of step ''''d''''.

3. The method as in claim 2 wherein said preheating and selective heating are preformed by electrical heating.

6. An apparatus for mass-production of skis which are mainly wooden in construction comprising: a. means for forming wood required for the skis into planks whose longitudinal surface is substantially parallel to the course of the wood fibers; b. means to combine and divide said planks into sheets of required size; c. a pre-heating elongated chamber wherein said sheets are continuously conveyed and are treated with an adhesive; d. a press-machine with conveyors and a constrained elongated passage with means to apply compression forces on a workpiece such as a wood-sheet-stack which is placed in said passage and is continuously conveyed, the press-machine including controllable heating means; e. a machining device which performs operations including at least one of milling, trimming, planing and grinding on a workpiece such as a said sheet-stack in continuous conveying motion; f. and an automated device which can do at least one of the operations of painting, screen printing and varnishing.

7. The apparatus as in claim 6 wherein said heating in steps ''''c'''' and ''''d'''' are electric resistance heating.

8. The apparatus as in claim 6 wherein at least one of the devices, i.e. preheating chamber, press-machine and the device as in ''''f'''' is of a multi-level type.

9. The apparatus as in claim 7 wherein said device as in ''''f'''' performs painting, screen printing and varnishing, and wherein this device and said preheating chamber and press-machine are each of a multi-level type.

11. The apparatus as in claim 10 wherein at least part of the equipment is adapted for being programmed.