US2018761A - Hand electric steering device - Google Patents

Description

- Oct. 29,- 1935.

F. S. HODGMAN HAND ELECTRIC STEERING DEVICE 2 Sheets-Sheet 1 Filed March 26, 1932 N INVENT R f'mmcx jflooam/v.

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III/II/I/IIIIII/Il/I Oct. 29,- 1935. F. s. HODGMAN 2,018,761

' HAND ELECTRIC STEERING DEVICE Filed March 26, 1952 2 Sheets-Sheet 2 INVENTOR 7! 7 1 BY v 24 t Patented Oct. 29, 1935 PATENT "OFFICE rump aaac'rnrc s'rsaamo navlcn Frederick S. Hodgman, Glen Rock, N. 1., assignor to Sperry Gyroscope Company, Inc., Brooklyn, N. Y., a corporation of New York Application March 25,

This invention relates to an electric steering gear for .dirigible craft, such as ships and aircraft. It is especially adapted for steering ships in which the manual work of turning the rudder by the pilot wheel is too burdensome for continuous operation. The purpose of the invention is to devise a practically. infallible arrangement so that in case of failure of the electric supply the pilot may continue to steer by hand through the same wheel by which he is controlling the ship electrically. A further object of the invention is to .simplify greatly, existing electric steering devices whereby many of the contacts, rheostats, and circuit-breakers, which are usual in the ordinary commercial motor installation, are eliminated. To this end the motor circuits are arranged to limit the maximum currrent flowing therethrough preferably by a resistance in series with the armature and at the same time to limit the amount of torque that may be placed on the motor by means such as a slip friction clutch. By this combination the danger of stalling and/or burning out the motor is largely overcome without theemployment of the usual rheostats, circuit breakers, or other safety devices and multiple relays.

By my invention I secure the further important result of not only relieving the pilot of the work of turning'the rudder through the handwheel but also of the labor of continuing the turning of the handwheel after it is once started or brought up to a. predetermined speed. In other words, by my invention the pilot (or helmsman) may steer through the pilot wheel (or hand wheel) as usual, or if he desires to move the wheel rapidly through large angles for maneuvering, he may initially bring the hand wheel up to a speed substantially equal to the follow-back speed from the steering engine, upon which the steering engine will continue to operate, turning both the rudder and the hand wheel until .the hand wheel is grasped by the pilot and stopped or the rudder limit switch is reached. By this arrangement, a very important improvement is secured for smaller vessels,

, such as tow boats having a limited crew. By it the pilot is relieved of much of the work of turning the pilot wheel and may thus, when desiring to move the rudder through large maneuvering angles such as midships to hard right, or hard right to hard left, or to any desired angle between hard left and hard right, simply start the wheel in the desired direction. He is then free to give attention to other duties, such as operation of main engines or observation "of other vessels, or of the effect of engine and rudder upon his "i032, Serial No. 001.322

own vessel, the wheel continuing to rotate until stopped by the pressure of his hand, or by the limit switch. Also by having a positive follow-up connection from the rudder to the wheel, the synchronism between the two is never disturbed.

This application embodies in addition to other matter, most of the features and claims contained in my prior application for Patent Serial No. 537,788, filed May 16, 1931 for Hand electric steering devices, and to that extent is a substitute therefor.

Referring to the drawings in which the preferred form of the invention is shown,

Fig. 1 is a diagrammatic view of my improved steering gear showing the pilot wheel and stand in elevation and the electric steering motor for turning the rudder.

Fig. 2 is an interior view on a larger scale of the stand supporting the: pilot wheel showing y novel lost motion device for bringing the steering engine into operation.

Fig. 3 is a simplified wiring diagram of one form of the invention.

, Fig. 4 is an enlarged sectional detail of the means for operating the control switches from the lost motion device.

Fig. 5 is a detail of the lost motion device showing the preferred yielding devices for causing automatic or hard-over operation of the steering engine.

Fig. 6 is a section taken on line 0-4 of P18. ii looking in the direction of the arrows.

Fig. 7 is a view similar to Fig. 6 showing a modified form of yielding connection for automatic operation.

Fig. 8 is a detail of a still different form of lost motion device.

Fig. 9 is a complete wiring diagram of the preferred form of the invention.

In Fig. 1 the usual steering wheel I is shown mounted on a standard or housing 2. If desired. an auxiliary wheel or hand grip 3 of lesser diameter than the main wheel i may be secured to the main wheel to facilitate quick turning of the rudder although, according to my invention, such auxiliary wheel is no longer as essential as heretofore. The wheels are shown as mounted on a shaft 4 which turns through bevel gears I the vertical stub shaft I. Said shaft does not lead directly to the rudder but there is interposed a to comprising a member I secured to shaft 6 and having a pair of broad teeth 80, Bil depending therefromleaving recesses or notches B, 8' therebetween. Below said member and loosely mounted on a shaft 9 is a collar It. In the-form shown in Figs. 2, 5 and '5 said collar is shown as having opposite pairs of projections ii, ii and 52, the former entering the notches 8 but being oi less breadth so as to allow a limited lost motion between the two elements 7 and iii. Below the member iii is anoth jaw member fixed to the shaft 9 and having teeth and notches it similiar to notches t" which are engaged by projections i2, the wholeforming a plurality of loose fitting jaw clutches.

Also, I prefer to provide on the edges of the lugs or notches in the several members strips of felt 55, 65 which serve to cushion the shocl: of engagement and lessen the noise. Whenever handwheel i is turned. therefore, through an angle greater than the combined lost motions be tween members and iii and i3 and i3, direct torque will be exerted from shaft t to shaft 9 so as to turn the rudder directly by hand. For this purpose the shaft 9 is shown as g ared to the rudder as throu bevel gears shaft i reduction gears 31' to the cable drum it; on which the rudder cables is are wound, the rudder being shown diagrammatically at 23.

Normally, however, before the lost motion is talren up, means are brought into action to operate the steering engine or motor 2 so as to turn the rudder by power and relieve the pilot of this work. For this purpose I prefer to provide the member 7 with a gear 22 which meshes with a pinion 23 journaled in a bracket 2 on the interior of the casing Member 13 is also provided with a similar gear 25 which meshes with a pinion lid on a. threaded sleeve 2". journaled in a similar bracket 24. Threaded in said sleeve is a shaft 23 which, adjacent its upper end. is provided with splines so as to be slidably but nonrotatably connected to pinion 23. It will readily be seen, therefore, that if one of members i or i 8 is rotated while the other member is stationary, that t e shaft 23 and sleeve 2'1 will be rotated relatively and thus raise or lower the shaft depending on the direction of relative rotation. As soon, however, as two pinions 28 and as rotate at the same speed, the raising or lowering of shaft 25 ceases. Adjacent the top of said shaft 28 is shown a grooved collar 39 in which a fork ti on a lever 32 engages. Said lever is shown as pivoted at 33 and carries at its outer end an electric contact 34 adapted to engage one or the other or stationary contacts 35 or 36 as the lever is rotated. Assuming the parts to be in the position shown in Fig. 2, if the handwheel i is initially rotated in the proper direction, shaft 253 will, for instance, be raised, thus closing contacts 3d, 3 5. This im mediately starts the motor 2i which turns the rudder until the contact is broken by the followbacl; connection from the rudder to the shaft and member 13 which rotates the sleeve to again lower the shaft 23. Normally, therefore. a given movement of the handwheel will move the rudder through a proportional angle.

Motor 2! is shown as connected to the rudder through reduction gears 39, connecting the shaft of the motor to shaft 48, which in turn is connected through reduction gears ll to an electromagnetic clutch member 42. Said clutch mem-- her is loosely mounted on the shaft 43 but when energized attracts armature 44 on the shaft to turn shaft". Shaft 43 in turn is shown as geared through reduction gears 45 to the shaft it. The clutch coil 42 of clutch 42 is normally maintained closed so that instant action is secured upon the starting of the motor 2! and slipping of the clutch is avoided. In case, however, the power goes off or the pilot desires to steer by hand alone, the clutch is automatically opened in the first instance because there is no power to energize the same. In the second instance the pilot opens the switch By this or a similar throw-out clutch the pilot is relieved of the worlr of turning over the heavy motor armature when steering the ship by hand. From the above it will be seen that the shaft i6 also acts as a follow back: connection from the steering motor M to the lost motion connection in the stand .2, thus turning shaft 9 and the member l3 whenever the rud der is turned to follow the movements oi the handwheel i and breal: the contact.

Preferably, however, I provide additional means toprevent the contact from being broken in case the pilot desires the steering motor to continue to operate after an additional movement q of the handwheel as hereinafter described.

The preferred wiring layout in simplified is shown in Fig. Q. In this figure the controller contacts 24 and Gir --33 operate respectively through relay magnets ill and 56. When contact ti e-3t is completed, secondary circuit is closed from one side of the line at the upper knife switch. of main circuit switch tl through 31-38, through 5?, through magnet and bacl: to the other side the line at the lower knife switch ll. The excitation of the magnet 9 closes contacts L-dill and 52-452. from one side of the line through contacts 5 [-4 5 thence through resistances 58 and til, thence through the armature and thence through contacts iii-J52 to series field H and thence back; to it tacts 5ii5l and through the armature E53 in the opposite direction than before and thence through the resistances lit, Eli, thence through contact 52'-i52', thence through the field in the same direction as bei'ore, and thence to the other side of the line. Therefore, the motor will be driven in the opposite direction. When both relays are deenergized, they establish back contacts 55 and 55' to cause dynamic braking by short circuiting the armature through resistance 5 8. The motor is shown as compound wound, the shunt field windings 5 i 6i beingcontinuouslt excited from the line so as to supply the field for dynamic braking. Limit switches 51, El are also provided to limit the throw of the rudder in each direction, said switches being shown as operated respectively by earns 58, 58' operated directly or indirectly by shaft d.

In addition to dynamic braking, an electromechanical brake is also provided for the mo tor shaft. Said brake is shown as spring ap plied but is held open by electro-magnet it! between one side of the line across the motor armature to the mid point of potentiometer resistor 8!, so that when the motor is running, the brake is off, but as soon as the current is inter- This completes a circuitv rupted to the armature, the brake is applied because the resistor Cl is very much higher than that -of short circuiting resistance 58, so that brake 60 is applied during the dynamic braking period as well as afterwards. The brake is preferably applied to the high speed armature'shaft ratherthan tothe lower speed cable drum i! or the intermediate gearing so that a small brake may be used. This resultis secured by keeping the clutch]! in engagement during the entire period of operation of the electric steering gear.

My armature circuit is preferably of unusually high resistance to limit the current surge in starting and obviate the necessity of auxiliary accelerating .contactors, For this purpose resistance 56 and also, if desired, a second resistance 56' in series therewith act as a current limiting resistance permanently coupled in series with the armature. This resistance,-therefore, limits both the current passing through the armature and the torque of the motor. Since the resistance of the water to turning the rudder when near its central or normal position is small, this does not interfere with quick starting. It also reduces the rudder speed near its limiting angle due to greater water resistance at large rudder angles. As

. distinguished from the usual load on commercial electric motors, a rudder does not require a large starting torque but on the other hand it is continually stopping and starting. If the usual commercial control is employed using a series of resistance contacts for starting up, such contacts are in continuous operation, resistances being cut in and out successively and continuously, resulting in excessive wear. Applicant proposes, however. to leaveresistances It, '6' connected in the motor circuit since no great starting torque is required and further to protect the motor and other apparatus applicant provides the slip friction clutch 42, ll hereinbefore described, which is designed to slip before the stall-torque is reached. My control, therefore, provides a minimum numberi of contacts and resistances in spite of the fact that dynamic braking is obtained.

Figs. 5 and 6 illustrate my preferred form of yielding device for maintaining the steering engine in operation after the handwheel is brought up to speed. I secure to the lug il a flat spring 66 which is firmly bolted at'a plurality of spaced points to the side of the ing as by means of bolts 81 and 68 and clamping plate 68'. Said spring is of a semi-circular shape and is preferably provided at each end with a roller is, I or other inclined surface adapted to engage or drop behind one edge of the lugs II or III in case the member I is rotated with respect to the member ID. Normally both rollers lie on top of lugs and Ill but in case the members I and Ill turn relatively in one direction one roller I snaps behind the advancing edge of the lug ll as illustrated in Fig. 6, or in case of opposite rotation the other roller 1 08 drops behind the edge I of lug ll, both edges being slightly beveled. The tension of the spring and the beveling angle and size of theroller are so chosen that when the handwheel l is released the follow-back from the motor will push the roller up out of the notch due to the inertia of the handwheel and associated gearing unless said wheel has been brought up approximately to the follow-back speed of the steering engine. In the latter case, however, the spring tension and friction are sufiicient to hold the roller against the said edge. thus holding a corresponding contact closed and maintaining the operation of the steering engine either until a limit stop is reached or until the operator grasps the handwheel l and stops it. A corresponding spring 92 may be provided between collar ill and the lower member II.

A very simple'form of yielding device for ac- 5 complishing this function'is indicated in Fig. 2 wherein a flat leaf spring 6" is clamped at its center to the center member l0 and bears at its upper and lower ends against members I and II respectively. The tension and friction of this 10 member are so adjusted that member I; will carry member I with it provided the member I has originally been brought upto the speed of member it, but if such has not been done the two parts will slip past one another and the con- 15 tacts at 34 and 35 (or 38) .will be broken.

In Fig. 7 a still different form of the invention is shown. In this form there is secured to the member 1' a sleeve 10 which may. if desired. be split. Said sleeve, adjacent its bottom, is prcll vided with a plurality of vetrical interior notches or vertical grooves H. Said member I! is provided with a plurality of radial bores or slots in which are placed springs II which press .out-' wardly small plungers 13. when said plungers g5 engage a vertical groove ll they tend to lock the members I' and II together but the friction is only sumcient to maintain said parts together if they are rotating at the same speed otherwise they are lneifective as in the other forms of the Q0 invention.

In Fig. 8 is illustrated a slightly modified form of lost motion device designated to give a large degree of lost motion. This form is quite similar to Figs. 2 and 5 in principle, but a plurality of in- I termediate collars l0 and I0" are employed instead of the single collar of Fig. 2, thus increasing the amount of lost motion permissible.

In accordance with the provisions of the patent statutes, I have herein described the principle 40 and operation of my invention, together with the apparatus which I now consider to represent, the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried 45 out by other means. Also. while it is designed to use the various features and elements in the combination and relations described. some of these may be almred and others omitted without interfering with the more general results outlined. and 50 the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patent is:

l. A hand electric steering gear for ships comprising an electro-mechanical steering engine, a pilot wheel capable of turning the rudder independently of said engine, a lost motion connection between said wheel and engine, means operated by initial operation of said wheel for bring-- ing said engine into operation to relieve the pilot. and yielding means for maintaining said engine operative when said wheel is manually brought maintaining the operation of the engine when the u I said wheel is started rotating by hand at a predetermined speed.

3. In a steering gear for ships, the combination with the usual steering wheel and rudder of a mechanical connection for turning the rudder from said wheel, a steering engine for also turning the rudder, means operable by initial movement of said wheel for bringing said engine into operation, said mechanical connection furnishing a follow-back connection normally stopping the engine when one ceases turning said wheel, and yielding means for preventing such stopping and automatically maintaining the operation of the engine when the said wheel is started rotating by hand at a predetermined speed.

4. In a steering gear for ships, the combination with the usual steering wheel and rudder. of a mechanical connection for turning the rudder from said wheel including a lost motion device, a steering engine for also turning the rudder, mean operable by initial movement of said wheel as permitted by said lost motion device for bringing said engine into operation, said mechanical connection furnishing a follow-back connection normally stopping the engine when one ceases turning said wheel, and yielding means for preventing such stopping'and automatically maintaining the operation of the engine when the said wheel is started rotating by hand at a predetermined speed.

5. In a combined hand and electric steering gear, the combination with the usual hand wheel and rudder, or a lost motion connectionbetween the wheel and rudder comprising a plurality of loosely fitting jaw clutches, a spring member on one clutch and having a slip-friction connection with another clutch, contact means operable from said connection when relative movement occurs between said clutches. a servo motor operated thereby for operating the rudder and having a follow-back connection to said clutches, said slip friction device tending to hold said contact means closed, if initially closed to cause continued actuation of said motor when said contact means is initially closed. s

6. In a combined hand and electric steering gear, the combination with the usual hand wheel and rudder and driving and driven shafts connecting the same, of a lost motion connection between the wheel and rudder comprising a plurality of loosely fitting jaw clutches, one of which is on the driving shaft and another on the driven shaft, slip friction means for yieldingly holding the jaws of said clutches together to take up said lost motion upon initial movement of said handwheel, a threaded shaft rotated from said driving shaft, a sleeve threaded thereon and driven from said driven shaft whereby, upon relative turning of said driving and driven shafts, said threaded shaft is moved axially, a steering engine for driving the rudder, means actuated by such axial movement for bringing said steering engine into operation, and a follow-back means from said engine to said driven member, sald slip friction means preventing disengagement of said ,5 jaws and consequent reverse axial movement of said threaded shaft until braking pressure is exerted on said handwheel.

'I. In an electric follow-up steering gear for ships, the combination with the rudder and motor I for turning the same, a pilot w eel, a mechanical follow-up connection from sa d motor to said wheel, a limited lost motion device in said connection, means brought into action by said device for operating said motor, and means for maintaining u said motor in operation when the pilot wheel isbrought up to follow-up speed whereby hard over rudder control operation is secured for large rudder movements while maintaining positive agreement between the rudder and wheel. 40

FREDERICK S. HODGMAN.

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