US1061932A - Control device for steam-engines. - Google Patents

Description

J. & J. R. WIGHAM. CONTROL DEVICE FOR STEAM ENGINES.

APPLIOATION FILED SEPT. 20, 1911.

Patented May 13, 19,13.

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V w a 7% Jr & J. R. WIGH'AM. CONTROL DEVICE FOR STEAM ENGINES.

APPLICATION FILED SEPT. 20, 1911.

1,061,932.' Patented May 13, 1913.

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UNITED STATES PATENT OFFICE.

JOHN WIGHAM AND JOHN BODI-IAM WIG-HAM, OF SOUTH HYLTON, SUNDERLAND,

. ENGLAND.

CONTROL DEVICE FOR STEAM-ENGINES.

Specification of Letters Patent.

Patented May 13, 1913.

Application filed September 20, 1911. Serial No. 650,348. h,

To all whom it may concern Be it known that we, JOHN lVIoHAM an JOHN RODHAM VIGI-IAM sub'ects of the King of Great Britain and Ireland, both residing at South Hylton, Sunder-land, in the county of Northumberland, England, have invented certain new and useful Improvements in Control Devices for Steam-Em gines, of which the following is a specification. The present invention relates to improve ments in or relating to control devices for steam engines and is particularly applicable to the controlling mechanism of steam steering gears. I I

The invention will be described in connection with the engine fonoperating the steering gear of a vessel, although it is, of course,also applicable to winding and other engines, where it may be desirable to control the engine from a distance.

The object of the invention is to provide means whereby loss of steam is prevented when the'steering engine is not actually in motion, and to lnsure a reliable closlng of the steam admission valve at that time.

A common fault in such gears is that into or out of action, a valve for admitting or cutting off steam is simultaneously operated to eifect a positive opening or closing motion of the steam valve to the engine. These means comprise a longitudinally movable member having a double incline or V trackway or gradient and a roller or member engaging in said trackway and connected through levers with a piston valve for controlling the stea-msupply for: the operation of the steam admission valve to the engine, the means beingsuch that steam is cut ofi from the enginewhen the reciprocatory control member is brought approximately to mid-position. P

The invention will now be describedas applied to a ships steering gear, Figure 1 showing the general arrangementof such a gear, with the movable trackway for the is a detail view in part section of a convenient form of the steam admission control devices, operated by the movable trackway, and Fig. 3 is an end elevation of Fig.2.

In the embodiment of our invention now to be described the engine 1 drives a crank shaft 2, provided with a worm or other form of gearing which drives a worm wheel 3, on the drum 4 on which the steering chain is wound. This worm also engages and drives a worm wheel 5 mounted on a horizontal shaft 6 carried in suitable bearings. This shaft, which may be called the control shaft, is provided with means, such as a flanged collar 7, for rocking a lever 8 for operating the slide valve or steam admission device in the cylinder 1. Upon this shaft 6 is rigidly mounted a slotted forging, yoke or bracket 9, having a V slot or slots or guides 10 for a roller 11,the motion of which causes the actuation of the admission valve 12 in the steam conduit to the engine. The other enduof this horizontal shaft has a "screw thread l3engaging the correspondingly threaded hub or bore of the worm wheel 5. This shaft also carries a bevel wheel 14' feathered on it, so that the shaft scan move longitudinally therein, but' must rotate with it.

This wheel 1 1 engages a second bevel wheel 15, mounted on a rod or shaft 16, which can be turned in or from the wheel house.

The action of the mechanism above described is as follows: When thebevel wheels 15, 1 1, are turned bythe shaft 16, they move the shaft (3 horizontally.say to the left (owingto the screwed part1?) turningin the worm wheel) and this horizontal movement effects the opening of the engine valve by the lever 8, and the roller 11 traveling up the gradient in the slot 10 causes the steam admission and cut off valve: 19 through lever30 and valve rod 18 pivoted thereto at 17 -to be operated to admit steam to the engine, this valve 19 moving down and bringing the port 20 into communication with the steam inlet Qatwhich opens into the space between the two disk ends of the piston 19. Steam then passes from the supply pipe 24, to the under side of and raises a piston 22, the rod 23 of which carries the valve 12 for controlling the inlet of steam to the engine 1. As soon as the engine starts it turns the worm wheel which, by means of 110- the screw 13, moves the horizontal shaft 6 in the opposite dlrection, and so closes the engine valve and also the cut off valve, by causing the roller 11 to travel down the slot 10'. Vhen the bevel wheels are turned in the opposite direction the shaft (3, is moved to the right, and the roller rides up the left hand slot, the engine being thus reversed while the control valve is operated in the same way as already described. It will be seen that when the roller is in the lowest position, e. at the bottom of the V, the control piston valve 15) is in its highest position, and the steam inlet 24 is in communication with the port 21, the steam thus acting upon the top of the piston 22 and keeping the valve 12 closed on its seat. The main steam supply is at 25,- a branch 26 leading from the steam chest 27 to the steam inlet 24: to provide the steam necessary for the operation of the control device.

To provide for the escape of steam from above or below the piston 22 a pipe 28 is provided leading to the condenser, so that there is never any counter pressure against the movement of the piston 22 in either direction. Hence within a very short time of the stopping of the turning of the steering wheel the engine comes to rest, through the steam being cut off entirely.

Vhile we have described the double-incline member as being directly mounted upon the control shaft 6, it may be mounted on a tube or sleeve which is keyed on the shaft, or it may be indirectly connected to the shaft in such manner as to be moved to and fro with it, or it might even be quite independent of the shaft, but so' mounted as to be moved by an abutment or projection from the shaft, a spring or springs being employed to assist the movement where necessary, provided the member is so arranged and mounted as to move to and fro in acordance with the movements of the control shaft. Further while we have found the V slot construction to be a very suitable form, the motion of the piston valve can be obtained by the reciprocating member on or operated by the control shaft being in the form of a cam, or the end of the lever arm 30 could be connected to the reciprocating member or shaft by means of a link, this link being vertical and the rocking lever horizontal when the piston valve is in the position corresponding to the closing of the steam admission valve to the engine. VVhatever construction is employed it is essential that the cut off valve, such as 12, shall be operated as to bring about a reliable opening and closing of the steam admission valve when the control shaft is operated.

It may sometimes be desirable or necessary in an emergency to fix the steam admission valve 12 open or out of action, and for this purpose we may provide the spindle 28 with a slot 29, or fixed collar, and a corresponding tapered key or distance piece which when inserted with hold the valve in position off its seat.

It is to be understood that the invention is capable of modifications in various ways, provided that the movable double-incline principle is maintained with the operation thereby of the steam admission to the engine in such a way that steam is cut off from the engine when the reciprocatory control member returns approximately to mid position.

, WVhat We claim and desire to procure by Letters Patent is:

1. A control device for steam engines comprising a reciprocatory control member, a double-incline trackway moved by said control member, alever one end of which is adapted to be rocked by said trackway, and means operated by said lever for cutting off steam from the engine when the control member is brought approximately to mid-position.

2. A control device for the admission valve of a steam engine comprising an operating piston for the admission valve, a reciprocatory control member, a doubleincline trackway moved by said control member, a pivoted lever adapted to be rocked by said trackway, a piston valve connected to said pivoted lever for controlling tfheadmi-ssionand cut ofi of steam to the operating piston of the steam admission valve, substantially as set forth.

3. A control device ,rfor steam engines comprising a reciprocatory control member, a pivoted lever adapted to be rocked by said reciprocatory member and a piston valve reciprocated by the movements of said rocking lever to cause steam to be cut off from the engine when the control member is in its mid-position.

4:. A control device for steam engines comprising a reciprocatory control member, a V-shaped trackway on said member, a rocking lever engaging at one end of the V-shaped guideway and means operated by said rocking lever for causing steam to be cut off from the engine when the control member is in its mid-position.

A control device for steam steering engines comprising a steam chest, a steam control valve therein, a piston connected to said valve, a piston valve controlling admission of steam to said piston, a piston valve rod, a rocking member attached to saidrod', a V-shaped' trackway engaging the other endof said rocking member and a reciprocatory control member carrying said V-shaped trackway substantially as set forth.

6.- In a control device for steam engines of the kind described, a reciprocatory control member, a V-shaped trackway thereon,

a pivoted lever rocked by the movement of said trackway and a steam controlling piston valve operated by said rocking lever in combination With a cylinder in communication With the casing of said piston valve, a piston in said cylinder, a valve chest and a steam admission valve connected to said piston, substantially as described.

. t 7 In a control device for steam engines,

the combination of a reciprocatory control shaft and a Vshaped trackWay mounted thereon, and means operated by the movement of said trackvvay for controlling the admission of steam to the engine, substantially as set forth.

In testimony whereof We afiix our sigma 15 tures in presence of two Witnesses.

JOHN WIGHAM. JOHN RODHAM WIGHAM.

Witnesses:

JAMES WHITELAW, FREDERICK PIATT.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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