FI89611B - Hatch construction for pressure grinding machine - Google Patents

Abstract

Hatch construction in pressure grinding machine, the said hatch construction comprising a hatch 2, displaceable along slide rails 6, with associated slide surfaces resting on the slide rails at at least one end of the hatch in sharp-edged scrapers 8 standing at an inclined angle to the longitudinal direction of the slide rails, which when the hatch is moved clear the contamination on the slide rail aside. <IMAGE>

Description

j 89611

HATCH STRUCTURE FOR PRESSURE GRINDING MACHINE

The invention relates to a door structure for a pressure grinder as defined in the preamble of claim 1.

The material feed hatches of pressure grinders must be tight to prevent pressure leaks. On the other hand, the hatches have to be opened and closed relatively frequently, e.g. at intervals of about 10 minutes 10, when a new charge is fed into the machine. Thus, the reliability and tightness of the hatches are essential factors in the proper operation of a pressure grinder.

The hatches usually rest automatically against 15 lubricated slide rails. However, lubrication also causes problems with the operation of the hatches. Since both smaller and larger fibers and sticks and other pieces are detached from the trees to be treated, they adhere to the grease that is easy to use and clump between the slide rail 20 and the sliding surface of the door. In current hatch structures, it is very common for contaminants to wedge the hatch so tightly into its guides that the hatch cannot be opened by its own power plant. There are also several cases where the seals of the hydraulic cylinder 25 used as a power unit have broken after the door is stuck.

In addition, continuous downtime causes large heat fluctuations in the grinding stones of the pressure grinder, breaking segment pieces of the stones. In the worst cases, 30 hatches have had to be opened by jacking them out. The production interruptions described above always last for several hours, sometimes even days, before the machine can be put back into service.

The object of the invention is to eliminate the above-mentioned drawbacks. In particular, it is an object of the invention to provide a new type of door structure which prevents the door from locking and keeps it always tight, clean and in working order.

With regard to the features characteristic of the invention, reference is made to the claims.

The hatch structure according to the invention is used in a pressure grinder, in which the wood to be treated is dropped through pressure-tight hatches into the sanding chamber for sanding against the sandstone. The hatch structure includes a hatch movable along the slide rails with sliding surfaces resting on the slide rails. According to the invention, the door structure of the hatch-10 comprises sharp-edged scrapers at an angle at least at one end of the hatch between the sliding surfaces of the hatch relative to the longitudinal direction of the slide rails. Thus, when the door 15 rests on a pair of Liu rails with two parallel edges and the door moves along the slide rails by means of a power device, the scrapers push the slide rails clean in front of the door, so that only

In a preferred embodiment of the invention, the edge of the scraper is formed by a substantially straight surface which is substantially perpendicular to the surface of the slide rail. Thus, the scraper is preferably formed by the sharp-edged edge of the sliding surface of the door.

In one embodiment of the invention, the outermost leading edge of the substantially straight surface of the scraper is arranged as a sharp, vertical edge, which further scrapes the side edge of the bone space and keeps it clean.

In another embodiment of the invention, the scraper consists of two substantially straight surfaces which form a sharp, vertical edge between them and which are substantially perpendicular to the surface 35 of the slide rail. Thus, the scraper is a plow-like structure that pushes contaminants from the surface of the slide rail to both edges.

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In a preferred embodiment of the invention, both ends of the hatch include scrapers according to the invention, the hatch having a scraper at each corner, i.e. four scrapers which clean the slide rails when the hatch is moved in either direction.

The structure according to the invention brings significant improvements to the problems of the prior art. In experiments with the prototype, it has been found that the jamming of the hatches 10 due to impurities on the surfaces of the slide rails has been completely eliminated by the hatch structures according to the invention.

The invention will now be described in detail with reference to the accompanying drawings, in which Figure 1 schematically shows a hatch structure according to the invention, Figure 2 shows another hatch structure according to the invention, Figure 3 shows the hatch structure of Figure 1 from below and Figure 4 shows a schematic view of a pressure grinder using a hatch according to the invention.

Fig. 4 shows a schematic view of a pressure grinder with two pressure-sealable hatches 2 and 3, between the chambers of which can hold a dose of wood 1 to be treated once. By opening the lower hatch 2, the wood is dropped into the sanding chamber 4, where it is pressed against the rotating sandstone 5. The present invention is directed to hatches 2 and 3. The hatch structure of the invention may be used in either or both of hatches 2 and 3.

Figures 1 and 3 show a corner of a hatch structure 1 according to the invention. The hatch 2 comprises a substantially rectangular and planar frame structure with its sheaths and has a sliding surface 35 7 at its lower edge, which rests on a sliding rail 6 of a suitable brass alloy, for example. and a sliding surface.

An oblique surface is formed on the edge of the door at the end of its sliding surface 7 at an angle of about 45 degrees to the sliding rail 6 5, which acts as a scraper 8 according to the invention. The surface is substantially perpendicular to the plane of the sliding rail. In addition, it forms a sharp, non-rounded corner with the sliding surface 7 of the door. This surface extends from the side edge of the door from outside the slide rail 10 6 substantially towards the central area of the door so as to extend to the other side of the slide rail.

Furthermore, in this embodiment the surface starts outside the door surface 13 perpendicular to its movement, and continues below the door edge 13 below the door 15, forming a cavity 14 below the door at the slide rail 6. The inclined wall of the chamber turns on the other side of the slide and returns to the edge surface 13 thus the cavity 14 through which the impurities scraped by the scraper 8 can drain off the top 20 of the slide rail 6 and fall down.

In addition, the vertical outer edge of the sloping surface is formed as a relatively sharp edge 10 which scrapes the side edge adjacent to the slide rail 6 and acts as a crusher, crushing the fibers and pieces of wood adhered thereto against a suitable abutment surface or piece.

In the embodiment of Figures 1 and 3, the scraper is placed partly under the door precisely because it does not take up too much space in the direction of movement of the door. Thus, it is also possible for the scraper according to the invention to be placed substantially completely inside the space delimited by the edges of the door. The application of Figure 1 is specifically intended for new hatches to be manufactured.

The application of Figure 2 has been developed for currently used hatches, in which the sliding surface of the hatch extends in the direction of its movement from end to end and it is not possible to notch space for the scraper in the lower surface of the hatch. In order to avoid increasing the length of the hatch and its structures too much in the direction of its movement, the curve 9 is formed of a substantially triangular plate-like body which is fastened on one side 5 against the edge surface 12 of the hatch 2. In this case, the other two sides of the body which are at an angle to each other and whose lower edges, which come against the slide rail 6, are sharp, form a plow. These two sides, i.e. the plow blades 17 and 18, extend from the common 10 vertical central edge 11 beyond the edges of the upper surface of the slide rail 6. Thus, as the door 2 moves on its sliding surface against the slide rail 6, the wings 17 and 18 plow away all impurities from the top of the slide rail. In addition, the vertical and sharp edge 11 between the surfaces is arranged in the extreme position of the door to press against a suitable abutment surface, whereby it cuts and crushes any impurities remaining therein.

The invention has been described above by way of example with the aid of the accompanying drawings, however, various embodiments of the invention are possible within the scope of the inventive idea defined by the claims.

Claims (9)

1. Cover construction of a pressure grinding machine, wherein the trees (1) via pressure-tight hatches (2, 3) fall into a grinding chamber (4) for grinding against a grinding stone (5) and to which the lid construction includes a sliding slide along the slides (6). associated with sliding surfaces (7) supported on the sliding rails, characterized in that the door structure belongs at least at one end of the door (2, 3) to the ends of the sliding surfaces (7) with respect to the longitudinal direction of the sliding rails (6). an oblique angle being sharp-edged scrapers (8, 9), which when the door is moved plows the contaminants eating on the sliding rails. 2. A hatch construction according to claim 1, characterized in that the edge of the scraper (8) consists of a substantially straight surface, which is substantially perpendicular to the surface of the slide rail (6). 3. A door construction according to claim 2, characterized in that the outer front edge of the surface forms a sharp vertical edge (10), which acts as a scraper against the side edge of the door passage through the door (2). 4. A lid construction according to claim 1, characterized in that the edge of the scraper (9) is formed by two substantially straight surfaces, which between them form a sharp edge (11) and which are substantially perpendicular to the surface of the slide rail (6). 5. A door construction according to claim 3 or 4, characterized in that the front edge of the door passage (2, 3) has a counter surface against which the vertical edge (10, 11) functions as a crusher. A hatch construction according to any of claims 1 to 5, characterized in that the sharp-edged scraper (8) consists of the sharp-edged edge of the hatch (2). R 9 611 A hatch construction according to any of claims 1-6, characterized in that the scrapers (8, 9) are located at each end of the hatch (2). 8. A door construction according to any of claims 1-7, characterized in that the scraper (9) is located on the outside of the edge surface (12) of the door (2). Door construction according to any of claims 1-7, characterized in that the scrapers (8) are partially located inside the edge surface (13) of the door (2) in a cavity (14) located at the lower edge of the door.