GB2124544A - Receiving and dispensing straw logs - Google Patents

Abstract

A straw log making machine of the kind described and illustrated in Patent No. 2071 560 B has a carousel unit (22) which aligns with, and/or defines, the compression chamber. A fluid operated ram (23) positively ejects the logs from the carousel. Each log is carried round for a finite time between leaving the compression chamber and reaching the log ejecting ram (23). In a preferred construction each log- receiving portion of the carousel unit is lined with a removable liner. In one embodiment (Figure 2) the logs are formed in the carousel unit as well as being carried round by it before ejection therefrom.

Description

SPECIFICATION Receiving and dispensing straw logs The invention relates to the production of loglike units comprising a compressed mixture of straw and a settable binding agent.

My prior UK Patent No 2 071 560 B describes and illustrates a machine for processing straw into log-like units for subsequent burning on an open fire, the machine comprising means for mixing with the straw a settable binding agent; means for transporting the mixture of straw and binding agent into a chamber whose walls define the cross-section of the desired log-shape; means for compressing the mixture of straw and binding agent against the far end of the chamber to cause the mixture to assume the desired log-like shape; means for opening the far end of the chamber to allow the compressed log-like mixture to be removed from the chamber; and means to repeat the above sequence of operations for a desired number of times.

Such a machine is defined herein as "a strawlog-making machine".

Amongst the prior art brought forward in the preliminary examination and search of my previous UK patent application is UK patent specification number 578 336. This shows an arrangement in which log-like units are produced and which is "a straw-log-making machine" as defined herein. The machine has an output chamber which exhibits a cooling jacket so that the "log" is progressively cooled as it passes along the output chamber.

This prior arrangement is clearly inefficient. A very long chamber is needed, the complexity of a cooling water jacket is inevitable, and differential cooling effects along the length of the chamber may affect the consistency of the logs and will, in practise, probably require constant monitoring of the product and adjustment of the machine's controls.

It may well be advantageous to have some stabilising period during which the logs produced by any such machine can cool, and generally settle, so that by the time they are handled there is less risk of them distorting.

The present application seeks to do this in a more efficient and product-consistent manner than the arrangement shown in specification 578 336.

According to the invention, a straw-log-making machine (as defined herein) has a carousel unit at the far end of the machine's compression chamber; the unit aligns with, and/or defines, the chamber, and in the first such case there are means which eject the logs from the chamber into the carousel; there are means which remove the logs subsequently from the carousel; and the carousel carries each log round for a finite time before said log removing means operate.

This finite time between compression in the log-producing chamber, and eventual despatch to a hopper and/or conveyor for example, gives each log time to stabilise and cool so that the logs can then be handled more easily and with less risk of distortion. These objectives are accomplished in an efficient and elegant manner.

The log-removing means may positively eject each log from the carousel. A proprietary means such as a fluid-operated ram can be used as the basis of this ejecting movement. There is then no need for the expense and complexity of any loghandling mechanism.

Each log, having left the compression stage, may be carried virtually all the way round the carousel, the log then being removed just before it would otherwise come into line again with the compressing means. The logs have maximum time to cool and stabilise before being removed from the carousel, and the carousel is used to best efficiency.

The logs in the carousel may be cooled by a positive circulation of fluid around the carousel.

For example there may be a water-circulating jacket cooling each log-receiving portion of the carousel.

The carousel may be finned to promote cooling of the logs, whether or not any fluid-cooling jacket is used.

Each log-receiving portion of the carousel may be lined. A lining will prevent wear, since the lining can be made of material much better adapted to resist wear than the main body of the carousel.

The lining may for example comprise a plastics material. The technology of plastics is now well known, and plastics materials in general are good heat insulators and will minimise the transmission of heat from the linings to the body of the carousel.

The linings may be removable, individually or as a set of linings. This has advantages for maintenance. It also enables one carousel body to outlast several linings or several sets of linings.

The carousel and log-removing means are preferably stationed adjacent a hopper and/or a conveyor, as mentioned above. This can do away with any need to stack or otherwide assemble the logs manually. The efficiency of the log-producing process is thereby increased, and the eventual cost of the logs themselves can be minimised.

The single figure of the accompanying drawings shows, by way of example only, one straw-logmaking machine embodying the invention. This machine is the best way currently known to the applicant of putting the inventon into practice. The machine shows the carousel and log-removing means in diagrammatic cross-section.

The basis of the machine is a straw-log-making machine as described and illustrated in my previously-published UK patent 2 071 560 B.

The reader is referred to that published application for details of how the basic machine operates. The drawing in this present application shows the carousel and log-removing means added onto the output end of the compression chamber of the basic machine.

The carousel 22 rotates about a central axis. It is driven by, for example, a suitably sized electric motor (not shown) and is geared to operate automatically in sequence with the compression piston 12 of the machine in a way which will become apparent as this description proceeds.

The carousel is prefabricated and is made up to hold, say, fifty lined cylinders each of which constitutes a log-receiving portion of the carousel.

These fifty cylinders are all equally circumferentially spaced about the same pitch circle. A cooling fluid jacket, not shown, surrounds the lined cylinders. The passageways of this jacket penetrate the body of the carousel 22. The design details are not of the essence of the present invention, and can be settled without inventive thought by the intended skilled addressee of this specification.

A fluid-operated ram 23 is stationed adjacent the carousel 22. The ram 23 is so positioned and so sized that its rod-end can enter each of the lined cylinders in the carousel 22, as each cylinder comes into line with the rod-end of the ram 23, and as the ram is extended then the rod-end first enters the cylinder lining and then passes right along it until it reaches the other end. When the ram 23 is retracted, its rod-end withdraws wholly from the carousel lined cylinder. As the carousel rotates about its axis, each of its lined cylinders is brought successively into line with the rod-end of the ram 23.

The carousel 22 and ram 23 are both located adjacent, and in this case above, the hopper 21 of the basic machine.

In use, straw logs are produced by the basic machine as described in my published patent 2 071 560 B. An empty cylinder of the carousel is initially in alignment with the output end of the compression chamber 14 of the machine. The mixture of straw and settable binding agent is compressed against the far end 1 9 of the chamber. The end gate 1 9 itself is then opened, in this particular instance by sliding up electrically; and piston 12 continues to extend along chamber 14 to push the newly-formed log into the initially empty lined cylinder of the carousel 22.

When the log is fully pushed into its receiving cylinder, gate 1 9 descends to close off the end of the compression chamber; piston 12 withdraws to accept the next incoming charge of material from the breach of the basic machine, for subsequent compression against gate 19; and carousel 22 rotates to bring the next empty log-receiving cylinder into line with the end of the compression chamber 14.

The procedure just outlined is repeated until the carousel 22 is full, i.e. in this case carries fifty logs.

As the fiftieth log is being pushed from the compression chamber 14 into the last empty cylinder in the carousel 22, ram 23 simultaneously enters the next cylinder in sequence to push the by-now-fully-cooled log out of that cylinder and into the hopper 21. Ram 23 then withdraws from the carousel cylinder as gate 1 9 descends and piston 12 starts to withdraw. When the carousel 22 subsequently rotates, the cylinder just emptied by ram 23 will be brought into line with the end of compression chamber 14 to receive the next newly-formed log from the compression chamber.

The sequence just outlined is repeated, so that there is always one empty chamber ready to be brought next into line with the end of the compression chamber. The logs once they leave the compression chamber are carried round in almost a full circle by the intermittently rotating and stopping carousel. They thus have ample time to cool and stabilise before being ejected by ram 23 into hopper 21.

The various synchronised movements of the components could be achieved by programmable logic circuitry. The means of moving, and governing the movement of, the operating parts can readily be supplied by the skilled addressee of this specification.

In Figure 2 the carousel unit defines the compression chamber of the machine. The operation of the carousel in its log-carrying function is similar to that of the one illustrated in Figure 1, and a similar ram 23 positively ejects the logs from the carousel unit into the hopper 21.

The carousel in Figure 2 rotates between two fixed circular plates 22a, 22b. A hole in plate 22a allows the mixture of straw and settable binding agent to be compressed by the main piston 1 2 against plate 22b. Another hole in plate 22a is aligned with an identical hole in plate 22b to allow ram 23 to eject the compressed logs which are carried round by the carousel for almost a full 3600 revolution before the log carrying portion comes into alignment with the two holes through which ram 23 operates. The movements of piston 12 and ram 23 are of course synchronised appropriately with the rotation of the carousel which is an intermittent rotation. Every time the mixture of straw and binding agent is compressed by piston 12, the carousel rotates to carry it round to ram 23. By the time it reaches ram 23, it has cooled and hardened sufficiently to be ejected into hopper 21.

Thus the Figure 2 embodiment does away with the need for the end gate 19 and increases the output of the machine.

Claims (6)

1. A straw log making machine (as defined herein) having a carousel unit at the far end of the machine compression chamber; the unit aligning with, and/or defining, the chamber and, where the unit aligns with the chamber, with means which eject the logs from the chamber into the carousel; means to remove the logs subsequently from the carousel; and with the carousel being constrained to carry each log round for a finite time before the said log removing means operate.

2. A machine in accordance with Claim 1 and in which a fluid-operated ram ejects the logs from the carousel.

3. A machine in accordance with Claim 1 or Claim 2 and in which each log, having left the compression stage, is carried virtually all the way round the carousel and is removed just before it would otherwise come into line again with the compressing means.

4. A machine in accordance with any of the preceding claims and in which each log receiving portion of the carousel is lined and the lining is removable.

5. A straw log making machine substantially as described herein with reference to and as illustrated in Figure 1 of the accompanying drawings.

6. A machine in accordance with Claim 5 when modified substantially as described herein with reference to and as illustrated in Figure 2 of the accompanying drawings.