US360972A - Steam-feed for saw-mills - Google Patents

Description

(No Model.) l 3 sheetssheet 2.

DE WITT C. PRBSCOTT. STEAM FEED FOR SAW MILLS.

No. 360,972. PatentedApr. 12,1887;

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, DE WITT C.` PRESGOTT.

STEAM EEED EOE SAW MILLS. No. 360,972. Patented Apr. 12, 1887.

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UNITED STATES PATENT OFFICE.

DE WITT CLINTON PRESCOTT, OF MARINETTE, WISCONSIN.

SPECIFICATION forming part of Letters Patent No. 360,972, dated April 12, 1887.

. Application filed August 2, 1886. Serial No. 209,798. (No model.)

To all whom t may concern.'

Be it known that I, DE WITT CLINTON Pans- OOTT, a citizen of the United States, and residing at Marinette, in the county of Marinette' and State of Wisconsin, have invented a certain new and useful Improvement in Steam- Feedfor Saw-Mills,which is fully set forth in the following specification, reference being had to the accompanying drawings, in which-` Figure 1 represents a front elevation of 'the saw-frame, saw-carriage, and steam-feed embodying my improvement; Fig. 2, a side elevation of the same, partly broken away; Fig. 3, a verticalsection of the same, taken on the line w a', Fig. 2; Fig. 4, a vertical section of the valve and valve-chest belonging to the steam-feed; Fig. 5, asection of the same, taken on the line y y, Fig. 4; and Fig. 6, a similar section taken on the line z z, Fig. 4. These figures of the drawings are on different scales, Figs. 1, 2, and 3 being onone scale, and Figs. 4, 5, and 6 on another and very much enlarged scale. I My present invention relates to yband-saw mills. Band-saws have been applied successfully to ordinary saw-mills for cutting up logs within a comparatively recent period. With modern improvements, however, this kind of saw is now in successful use for sawing logs, and is growing in favor with saw-mill operators. In 1876 Letters Patent No. 174,004, dated February 22, were granted to me for a steam feed mechanism for saw-mills, which patent was reissued April 9, 1878, N o. 8,160.

The object of my present invention is to apply a steam feed device to a band-saw mill.

The saw-mill, which is represented in the drawings, or at least such parts of the bandsaw mill as are there shown, is the subjectmatter of a separate application filed by me July 3, 1886, Serial No. 207,142, to which reference is made for full information.

Inthe present case it is not necessary to describe all the parts of the mill, and, indeed, I have not shown all in the drawings, only those being illustrated which are essential to au understanding of the presentimprovement, and Ishall only briey refer to these parts.

The steam feed mechanis'm is in all general features like that described and shown in my prior patent, Reissue No. 8,160,0f April 9, 1878, to which reference is here made for a full description. I shall here describe only such parts as are necessary to understand its application to the band-mill.

I will now proceed todescribe such parts of the mill as are necessary to an understanding of the construction and operationof the mechanism by which I have embodied my invention practically in one way, and will then point out denitely in the claims the special improvements which I believe to be new and wish to protect by Letters Patent.

In the drawings, Arepresents the saw-frame, which is upright, as usual in this class of saws, and is mounted upon timbers A of the iloor. At the upper end Of the frame is the upper band-wheel, B, and below the frame is the like lower wheel, B. plied to these wheels in the usual manner, and guides c are arranged on the working side of the frame above and below the log for-the purpose of steadying the saw. The log-car- 'riage D is of any usual construction, and is mounted in the ordinary manner upon tracks d, on which the truck-wheels d of the carriage run. A steam-cylinder, E, is arranged below the log-carriage in the usual manner for the application of my patented steam feed mechanism. rIhis cylinder is provided with a piston .which is connected to the carriage, the general arrangement and operation of these parts being as set forth in the patent, Reissue N o. 8,160.

A steam-chest, F, is below the carriage and cylinder, and is supplied with steam by the supply-pipe G, coming from the boiler. Feedpipes H and H lead from the steam-chest to the front and rear ends, respectively, of the Asteam-cylinder, thereby providing for the admission of steam to the latter on either side of the piston, as may be required. Ihave found that the usual way in which I operate this steam feed mechanism in connection with circular saws will not answer for /band-saws. Heretofore the' valve employed has been of such construction as to let on the steam at once to feed the carriage up to the saw, thus bringing the log to the saw and driving it through with full force. .I have found that this will not answer for a band-saw. The carriage for a band-saw'must be handled with great care and with varying speed, according to circumstances. Sometimesinlarge logs the carriage The band-saw C is apy should barely move along; but its speed may be increased as the log is worked down, or with smaller logs. The control of the carriage must be perfect and capable of regulation to a considerable degree of nicety. I have therefore devised an improvement to the valve mechan ism by which this steam-feed is made applica ble to band-saw mills, to which it could not otherwise be applied. The steam-chest F is provided with ports g for the supply-pipe, and h it for the respective feed-pipes to the cylinder. This chest is constructed substantially as shown and described in Letters Patent No. 215,293, granted to me May 13, 1879, to which reference is made for a more complete description. A sleeve, I, is mounted in the valvechest within the port h, through which steam is admitted to the front end of the cylinder for feeding the carriage to the saw for work. The valve J', which is of similar construction to that shown in my prior patent, just mentioned above, plays through this sleeve--that is, the inner end of the valve is arranged within the sleeve, as seen in Fig. 4 of the drawings, and reciprocates therein. Openings are made through the sleeve into the port. These openings are preferably of triangular shape, arranged with the apex pointing inward toward the valve, and some of them, i, are long enough to' extend quite across the port, while others, i', are 'much shorter. If preferred, however, they may all be of the same length and extending across the port, or substantially so. Any other form may be given tothese openings, provided they are constricted toward the valve.

The valve J is constructed substantially as in Patent No. 215,293, being cylindrical, and provided with openings]l andj. In Fig. 4 of the drawings the valve is shown in position after the carriage has been gigged back and is ready for its forward movement toward the saw. It is evident that if the valve is now thrown over toward the port h the steam escaping from the openings j into the latter must pass through the openings i and z" in the sleeve I, and the portions of these openings first uncovered will be the narrow parts of the openings t'. Obviously, therefore, at the irst the supply of steam to the feed-pipe H will be small, in fact, just enough to start the carriage. As the valve is moved by the attendant, this supply will be gradually increased by the uncovering more and more of the openings i, and finally of the shorter ones, i', as the valve moves past them. The movement of the carriage under this operation may be regulated so as to move very slowly, or at any speed desired up to that produced by the full force ofsteam intended to be supplied through this feed-port. The carriage is completely under the control of the attendant, who can regulate its movement with great nicety. All danger of injuring the saw is in this way obviatcd, and the steam feed mechanism is made perfectly practical and operative for band-saw mills, and performs the same efficient work with practically the same advantages as it does in circular mills. In order to operate the valve, it is connected by a rod, K, with a crank, it, on a'rock-shaft, L, the other end of which is provided with a crank-arm, Z, to the outer end of which a hand-lever, M, is connected by the link m.. The mechanism is thus placed under the control of the attendant or sawyer, who manages it by working the lever M, whereby he moves the valve as deslred.

The operation and construction of the port h and the valve-openings j are substantially as in my former patent, referred to above, as there is no necessity for graduating the movement of the carriage backward. The exhaust is also the same, the chest being provided with an exhaust-port, a, leading to an exhaustpipc, N, which is connected therewith.

The sleeve device described above is especially adapted to the particular' kind of valve here shown, which is cylindrical and balanced. It is not absolutely necessary that this particular variety of valve should be used with my steanrfeed, though I have found it preferable to others. It will be necessary, however, if a valve of any other construction is used, to provide a device for regulating or graduating the passage of steam into and through the port corresponding to the port It in this instance, and this may be effected by a device similar to the sleeve here shown, the form and shape of the latter being changed to adapt it to the particular form of valve and port which is employed. In some instances, however, it may be necessary to provide a device constructed or arranged very differently, but still admitting the steam gradually to this port, or to the feed-pipe corresponding thereto. Some device of this nature will be found necessary with the feed operating in connection with a bandsaw.

I do not wish to bc understood as limiting myself to the details of construction herein shown and described above, for, as already stated, there may be changes in the vital part ofthe mechanism, and, obviously, changes may be made in other parts which have been mentioned above to a very great extent without departing from the invention herein set forth.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a saw-mill, a band-saw, in combination with the log-carriage, a steam feed device connected to thc carriage, and a graduating device, whereby steam is admitted to the cylinder gradually for the forward movement of the carriage, substantially as and for the purposes set forth.

2. In a saw-mill, a bandsaw, in combination with the log-carriage, a steam feed device connected to said carriage, a valve for admitting steam alternately to the feed-pipes leading to the front and rear of the steam-cylinder, and a device covering the portopening to the former of said pipes, and provided with graduated openings, whercby steam is supplied in small quantity atfirst and gradually increased, substantially as and for the purposes set forth.

IOO

3. The saw-carriage, in combination with the steam-cylinder, piston arranged therein, feed-pipes opening into the cylinder in front and rear of said piston, steam-chest provided 5 with ports h la', reciprocating Valve J, and sleeve I., provided with openings gradually constrioted as they extend inward, substantiaily as and for the purposes set forth.

4. The saw-carriage, in combination with Io the steam-cylinder andv piston, the feed-pipes' H Hf, the valve-chest F, provided with ports h h', the reciprocating valve J, yprovided with openings j j, and the sleeve I, provided with tapering openings 'i i', the latter shorter than the former, substantially as and for the pur- I5 poses set forth.

DE WITT CLINTON PRESCOTT.

Witnesses: Y

W. P. MARS, JOHN J. ANDREW.

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