US 1227639 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
. IVIANLY C. [VI
v.DISTANT CONROL APPARATUS.
APPLICATIQN FILED JULY|G1909.
Paten-ted may 29, 1917.
n FEW. i@
! No. no.
` with it.
' ses! rr non.
CRLES MATTHEWS MANLY, OF BROOKLYN, NEW YORK.
DISTANZE CONTROL APARATUS.
control apparatus in which a primary control mechanism when manually adjusted causes one or more secondary control mechanisms, sltuated at any distance therefrom,
and not having direct mechanical connection thereto, to operate in synchronism My object is to provide simple and effective means in such mechanisms as that designated, for causing the secondary control mechanism to move in synchronism with the movements of the primary control mechanism situatedat any distance therefrom, and to remain in such positions as it has been caused to move to until it is moved therefrom in synchronism with the primary control mechanism. Another object is to provide means whereby such result may be obtained even when the primary control mechanism and secondary control mechanism or mechanisms have motion relative to each other, and my further lobject is to provide means for obtaining this result without direct `mechanical connecting parts between the said mechanisms.
With these objects in view my invention consists of a control or signaling apparatus embodying a primary control mechanism, one or more secondary control mechanisms i and means for causing the said secondary control mechanisms to operate in synchronism with the operationv of the primary control mechanism and to remain fixed 1n such positions las thereby caused to attain until moved therefrom in synchronism with the primary control mechanism as hereinafter more particularly pointed out in the claims; and my invention further consists in the novel construction and details thereof with reference to the accompanying drawings, as hereinafter described, and more particularly pointed out in the claims.
Specification of Letters Patent.
by the screws 11, the
p corresponding cylinder cap,
the same designating numerals refer to the same or corresponding parts` in all the views, the numeral 1 indicates a c linder in which is slidably mounted a plston 2 from one end of which projects a piston rod Patented May se, reir. iApplication filed July 16, 1909. Serial No. 508,057.
3, while from the other end projects a piston rod 4, the said rods beingfastened to the said piston by the pins 5 and 6 respectively. Closing one end of the cylinder 1 is a cap 7 fastened thereto bythe screws 8 the said piston rod 3 passing through the bore 9 of the cap 7, while the other end of the cylinder 1 is closed by a cap 10 fastened thereto piston rod 4 passing through the bore 12 of the cap 10.
Formed on the ,piston rod 3 at a point intermediate of its length, is an enlargement 13, thereby providing the two shoulders 14 and 15. Slidably mounted on the rod 3 is a tube 16, provided at one end with an in-l terior flange 17, which slidably fits the rod 3 between the shoulder 14 and the'piston 2. Formed at the other end of the tube 16 is an exterior flange 18, and mounted on the tube 16 is a spring 19, one end of which acts against the flange 18 and the other end against the piston 2. Similarly on the plston rod 4 is an enlargement 20 providing two shoulders 21 and 22, and slidably mounted on it is the tube 23, provided with the interior flange 24 and the exterior flange 25, co-actingwith the spring 26. The location of the shoulders 14 and 21 and the distance from the inner side of the inner lianges of the tubes to the outer side of the exterior flanges is so chosen with reference to the distance between the two cylinder caps 7 and l0 that when the piston 2 is at its midpoint the ends of the tubes 16 and 23 preferably minutely contact with the cylinder caps 7 and 10 respectively. As soon as the piston 2 is moved the slightest bit to either side of its mid position, the end of the tube on that side will act against the thereby causing respectively.
the spring on that side to be compressed, thereby tending to return the piston to its mid position, and unless acted on by some exterior force the piston will therefore tend to remain in its mid position.
Formed on the side of the cylinder 1 is a valve chamber 27, in which are formed the two ports 28 and 29 respectively, and mount# ed in the said valve chamber 27 is a valve 30 provided with the four heads"31, 32, 33 and 34. In the normal position of the said valve 30 the head 32 covers the port 28 and the head 33 covers the port 29.
Formed in one edge of the head 32 are small V-notches or slits 35, while in\the opposite edge of the same head are correspondl ing notches 36, and the head 33 is also provided with corresponding notches 37 and 38 The distance between the points of the V-notches on one side of each head from those on the other side of the same'head is made equal to the width of the port 28 for the head 32, and equal to the width of the port 29 for the head 33. Formed in the side of the valve chamber 27 are annular passages 39 and 40, which conr nect the ports 28 and 29 respectively," with the pipes 41 and 42 respectively. Formed I in the opposite side of the valve chamber are passages 43 and 44 which are connected together by the passage 45, the latter finally connecting with the pipe 46. Formed in the side of the valve chamber between the passages 39 and 40 is the passage 47 which connects with the pipe 48.
Mounted on the base plate 50 on whichthe cylinder 1 also is mounted, is a'source of fluid pressure supply, which for convenience, 1 have here illustrated as consisting of a gear pump 51 of the conventional form, but not shown in detail. The pipe 46 is connected to its suctionside and the pipe 48 to its pressure side, the said gear pump being driven by some'sourceof power, which for convenience, I have here illustrated,l as a small electric motor 52. Placed at a point intermediate of the length of the pipe 46 is a reservoir or tank 53, and connecting the pipe 46 to the pipe 48 is a pipe 54, in the circuit of which is placed a relief va'lve 55, here shown as of a conventional form, which permits fluid to pass from the pipe 48 to the pipe 46 when the said fluid has reached a predetermined pressure suiiicient to over- 'come the force of the valve spring 56.
'Formed in the side of the cylinder 1 are two passages 57 and 58, through which the two pipes 59 and 60 respectively, are connected to theinterior of the said cylinder, the pipe 59 being continuedl to connect with the pipe 41 andthe pipe 60 to connect with the pipe 42, previously described. Mounted.
fits the cylinder 1.
fastened thereto by the pins 6 4 and 65 respectively. v
Formed on the' yoke 61 is a in 66 which ts in the slot 67 in one end of the link 68, the said link being pivoted to the valve 30 by the pin 69. Formed in the other end of the link 68 is a slotl 70 which co-acts with the pin 71 formed on the yoke 72 on the rod 73, the said yoke being prevented from sliding thereon by the collars 74 and 75 secured to the said rod by the pins 76 and 77. Projecting from the side of the valve chamber 27 is a bracket 7 8 in the bore 79 of whichI the rod 7 3 is slidably and rotatably mounted. Formed on the side of the cylinder 1 is a bracket 80 .pro-vided with a bore 81 in which. is 'slidably mounted the bushing 82 the exterior of the said bushing being provided with the key-way 83 into which the top 84 of the thumb screw 85 projects.A rlhe tip of the said thumb screw co-acting with the key-way 83 prevents the bushing 82 from being rotated, but permits it to slide back and forth in the bore 81 of the bracket 80.
Formed onv the rod 73 are raisedfscrew threads 86 which coact with the screw threads 87 in the bushing82. The right ,The mechanism just described constitutes what ,I have termed, for convenience, the
primary control mechanism.
fPlaced at anydeslred dlstance from the prlmary control mechanism 1s a secondary control cylinder 101 which for simplicity of adjustment may be identical in all respects with the primary control cylinder 1 andy in whichA are mounted parts identical in all respects with the corresponding parts in cylinder 1. The piston 102 is fitted to the cylinder 101`with as nearly the same degree of frictional resistance as the piston 2 Similarly the piston rods 103 and -104 fit the bores in the caps 107 and 110 respectively with the same degree of friction as their corresponding parts in the primary control cylinder.` The spring 119 is as nearly as possible an exact, duplicate of the spring. 19 and the spring 126 is similarlya duplitate of the spring 26.` Connected to the passages 157 and 158 in the side of the cylinder 101 are the twopipes 159 and 160 respectively, the said pipes connecting through the swing joint 200 (hereinafter described) with the pipes 59 and 60 respectively, the two latter pipes being prolonged thereto beyond the point where they connect with the pipes 41 and 42 respectively, as previously described.
1f the apparatus or device which it is desired to control at a distance, oders only a small resistance to its operation, such operationmay be performed by the mechanism as now described. Such an apparatus is shown at the right hand end of the 'secondary cylinder.
161 which is 't'us or device to ,ary cylinder 101 where the supposed object 1s `to -swing the pointer 189 to any desired point on the quadrant 190 under the control of theoperator whois situated at the primary control mechanism at a distance `from thesaid pointer 189. For this purpose I attach to the cap 10 of the cylinder 1 an exactly similar quadrant 90 over which the pointer 89 may move, one end of the pointer 89 terminating in a ball 91 which is lightly pressed by the spring 92 against the end of the piston rod 4, the pointer 189 also terminating at one end in a similar ball 191 which is'alsolightly pressed against the piston rod 104 by the duplicate spr'ing 192. Protruding from the cap 10 of the cylinder 1 is a split collar 93 which may' be clamped to any desired eX- tent by the thumb screw 94, while protruding from the cap 110 'of the cylinder 101 is a similar collar 193 provided with the thumb screw 194 for clamping it. By means of these clamping collars, any difference in the friction of motion of the coperating parts of either cylinder as compared with that of the other cylinder maybe balanced by suitably adjusting the proper one of these collars.
Where the resistance to operationA of the apparatus or device to be controlled at a distance is considerable, I find it advantageous to employ other means, which I.
will now describe, rather than to impose on the-piston rod of the primary control cylinder a frictional resistance equal to that encountered by the piston rod of the second- This is especially advantageous where the resistance of the apparabe controlled is very heavy and is imperative where the said resistance iiuctuates, the degree of such fluctuations being usually unknown to the operator who therefore cannot adjust the friction of the primary control mechanism to correspond with that encountered by the secondary con- Mounted on the piston rod 103 is a yoke prevented from sliding thereon bythe collars 162 and 163 and the pins 164 and 165. lProjecting from the yoke 161 is a pin 166 which fits in the slot 167 in the end of the link 168. The link 168 is pivoted at its center by the pin 169 to the valve 130, the other end of the said link terminating in a slot 170 which ts around the pin' 171 which projects from the yoke 300 or whatever form lof part it is desired to move to effect the desired distant control. Assuming, however, that the yoke 300represents such a part as it is desired to move to control some apparatus of which it is a part, the said yoke 300 is secured to the piston rod 301 between the nuts 302 and.303, the other endiof the said piston rod 301 terminating in-.the piston 304 which is mounted .opposite sides of each cylinder and the "fined with a Huid,
yif the closed by the heads those formed in the valve 30, the distance between the points of the V-notches on the head being just equal tothe width of the chamber 127 are the three passages 143, 144 and 147, to which are connected the pipes 145, 146 and 148, respectively. Formed on the side of the valve chamber 127 is the bracket 178 provided with an arm which reaches over to, and forms a support for the' cylinder 101, thus maintaining the said valve chamber 127 at their proper relative positions. f
The operation of the device is as follows:
Assuming all the ports and passages of the primary control mechanism, as well as the cylinder.101 and its connecting pipes, of the secondary control mechanism, to be preferably a non-comsuch as oil or water, and a reserve supply to exist in the reservoir 53; gear pump 51 be rotated by some such source of power as the electric motor 52, and in such a direction as to cause the gear pump to force out fluid into 'the pipe 48 and to draw it in through the pipe 46, with the parts in the position shown, the ports of -the control valve chamber 27 being of the valves 30, pressure will rise in the pipe 48 until finding no egress it raises the blow-oil' valve 55 against the spring 56, permitting the eX- cess fluid t'o blow off at such a pressure back into the suction side of the pump, thereby short circuiting the Huid, but so long as the gear pump is kept in motion the pressure in the pipe 48 will remain constant at the amount necessary to keep' the relief valve 355 blowing ofi". With this pressure 'existing in the pipe 48, if the operator now moves the rod 73 longitudinally either by pushing or pulling on it, or by tion of the control rod 73 will cause the coacting end ofthe link 68 to be moved in the same direction, and the said link fulcruming at its other end on the pin 66 will cause the control valve 30 to be forced in the same direction. Assuming that such displacement of the rod 73 is toward the left, the control valve 30 will be displaced toward the left, thereby uncovering the port 28 and permitting fluid pressure from the ,pipe 48 to pass through the ll-notches 36 into the said port'28 and from thence ports 128 and 129 re-l' spectively. Formed in the side of the valve rotating it in the bushing 82, such mothrough the pipe 41 and pipe 59 into the left hand end of the primary control cylinder 1. Such fluid pressure passing into the left hand end of the cylinder 1 will act on the piston 2 to force it to the right and in forcing it to the right will compress the spring 26 vin proportion to the extent that the said piston moves in this direction. As soon, however, as the piston 2 moves toward the right it will pull the piston rod 3 in the same direction thereby, through the yoke 61 and pin 66, causing the lower end of the link 68 to be moved in the same direction and the upper end of the said link 68 fulcruming on the pin 71 will cause the control valve 30 to be forced toward the right until the head 32 again covers the port 28. At the same time that the piston 2 moves toward the right the piston rod 4 will force the lower end of the pointer 89 in the same direction, thereby causing the other end of the pointer to move toward the left or in a counter-clockwise direction with reference to the quadrant 90. At the same time that the ii'uid pressure, admitted through the control valve 30 into the pipe 41, passesl into the pipe 59 and from thence into the left hand end of the primary control cylinder 1 the same iuid pressure also passes through the pipe 59, the swing joint 200 and the pipe 159 into the left hand end of the secondary control cylinder 101, the frictional resistance to motion having been adj usted to equal amounts in both the primary and secondary control cylinders, as previously explained, and the corresponding springs in the said cylinders being of equal stiffness, the piston 102 in the cylinder 101 will be forced to the right at the same time, and to exactly the same amount that the piston 2 is forced to the right in the cylinder 1, and the piston rod 104 acting onthepointer 189 will move the upper end of it in the same direction on the quadrant 190 and to the same amount that the pointer 89 was moved on the quadrant 90 y the action of the primary control piston rod. At the same time that fluid pressure passes through the .pipe 41 and pipes 59 and 159 into the left hand ends of the cylinders 1 and 101 respectively any liuid expelled from the right hand end of the said cylinders 1 and 101 is free to pass through.
the pipes 60, 160 and 42 into the port 29 and from thence through the notches 38 into the passages 44 and 45, and from thence through the pipe 46 into the reservoir 53, and onv the supposition that all the ports, passages and cylinders were filled with fluid to start on, exactly the same amount of fluid would be returned to the reservoir as was taken from the high pressure pipe 48, the total quantity in circulation remaining constant. Similarly, if the rod 73 lbe moved toward the right, the cons ome source of matteo trol valve 30 will be moved toward the right, thus permitting duid pressure to pass from the pipe 48 through the notches 37 into the port 29 and from thence through the pipes 42,60 and 160 into the righthand end of the cylinders l and 101, and the pistons 2 and 102 will be thereby simultaneously moved to the left until the motion of the piston 2 to the left acting on the link 68' pulls the control valve 30 back to its, neutral position, thereby shutting 0E the admission of further fluid pressure to the cylinders. It is thus seen that the motion of the primary control piston and its piston rod not only move in a direction determined by, and to an extent proportional to,
the movement of the primary control valve,
sion Aof uid unless the control valve be' further moved by the operator, but the piston is locked in this position, since no fluid pressure can either pass into or out of the cylinder without further manual operation of the primary control valve. It the amount of force required to operate the lapparatus which it is desired to control at a distance is very small the device as now described in its operation is suiicient,'for the operator may by moving his control rod 7 3 bring the pointer '89 to any desired point on the quadrant 90 and thereby cause the pointer 189 to be moved to an exactly corresponding position onthe quadrant 190, no matter what the distance which separates the primary control mechanism from the secondary control -mechanisnr If, however, the resistance to operation ,of
the device to be controlled at a distance be considerable, and especially if it vary in amount from time to time, or cause reactions on the secondary control piston, the apparatus as just described in its operation would tance may be eii'ected by power derived from such secondary source and thereby prevent either reactions on, or variations in the resistance encountered by, the secondary control system.
When used in this way the operation of the device is as follows:
supposing the ipe 148 to be connected to uid pressure supply (not shown, but which may be a duplicate of the gear pump 51 driven by a duplicate of the electric motor 52, if desired) and the pipes 145 and 146 to be connected together and to 4 the suction side of such secondary source of iiuid pressure supply, uid pressure will exist in the valve chamber 127 between the heads 132 and 133, and supposing, as previously explained, that the yoke 300 represents a' part of the apparatus to be controlled where the resistance to motion is either variable or considerable in amount or both, any movement of theJ primary control rod 73 will cause corresponding movement of the pistons 2 and 102 and such motion of the piston 102 through its rod 1.03 will act on the lower end of the link 168 and thereby cause the secondary control valve 130 to be moved in the samev direction as the-piston 102 and to a corresponding amount. If the piston 102 moves toward the left, the port 129 will be uncovered by the head 133 permitting iu'i-d pressure to pass into the left hand endy of the cylinder -305 where it will act against the piston 304 and force' it together with the yoke 300 to the right until such motion of the iston 304 actin on the upper end of the link 168 causes the secondary control valve 130 to be moved to its neutral position, thereby shutting off the admission of further Huid pressure, and since at the same time the exhaust of Huid from the right hand side of the piston 304 is shut off by the i valve head 132,the piston 304 will be locked in such position as it has been moved to until again moved -by fluid pressure admitted by the secondary control valve 130. y
Similarly motion of the'secondary control piston 102 to the right will cause the secondary control valve 130 to be moved to the right, thus permitting fluid prcssureto pass into the right hand end'of the 'cylinder 305, thereby forcing thel piston 304 to the left until such motion of it returns the secondary `control1va1ve 130' to its neutral position. It
is thus seen that lbyusing the 'secondary'control mechanism, as f at rst described, merely for the operation of the secondary control valve, the resistance'vmotion of which can be made as small and as constant as desired,
. and using a secondary source of power for effecting the adjustment lof the p'art'which it is desired to operate at a distance, the
movement of the said part -at a distance may keptl in absolute synchronism with the 1 motion of the primary control mechanism.
In some applications of the above described mechanism, I' have found it necessary to provide means for enabling the sec- 'ondary control mechanism as aunit'to have motion relative` to the primary control mechanism or vice versa. lOne of the specialv l cases of this kind has been where the primary control mechanism was situated on-a part which had a motion. of rotation 4with reference to the secondary control mechanism. In such cases I employ the swing joint 200 which is shown in detail on an enlarged scale in Fig. 2. The pipes 59 and 60 are each connected to the lower plate 201, the pipe 59 through the passage 202 being connected with the circular channel 203 formed in the said plate 201, while the pipe 60 through the passage 204 is connected with the outer circular channel 205 formed in the said plate 201. The p'ipe 159 is likewise connected by the passage 206 to the inner circular channel 207, while the pipe 160 through the passage 208 is connected to the outer circular channel 209, both formed in the lower face of the plate 210. The two plates 201 and 210 are held together by the two guard rings 211 and 212 fastened to each other by the screws 213,the plates 201 and 210, however,- being free to rotate with reference to each other. Formed in the center of the two pla-tes are the bores 215 and 216 respectively,
through which a central plug or any other desired part may be passed. It is readily seen that bythis means the primary control mechanism and the secondary control mechanism will perform their functions properly even when one possesses motion with respect to the other.
In turning up the primary and secondary control mechanisms so that the motion of the primary piston and secondary piston will be in exact synchronism, I find it advantageous to ma e the resistance encountered by the Huid pressure in passing to the secondary control mechanism as nearly as possible the same as that encountered in passing from the primary control valve to the primary control cylinder, and the more nearly the two mechanisms are required to work in synchronism the more nearly all the parts and conditions in one mechanism should be duplicates of, or properly. proportioned to, the corresponding parts and coning inthe bracket 49 of the base plate 50 and lsecured tothe said piston rod. is a gear wheel' 95 which meshes with a pinion 96 mounted on the shaft 97 of the gear pump' 51. Similarly the piston rod 103 is extended tothe left and given a bearing in the bracket 178 and secured 'to the piston rod is a gear wheel 195 meshing with a pinion 196 secured to the shaft 197 which is journaled in the ends of the brackets 178 and 198. Whenever the gear pump 51 isl rotated to generate vto get out of mesh with the pinion 96. Similarly assuming the shaft 197 to be given a motionof rotation from' some external source of power, not shown, whenever the secondary: control mechanism is at Work the 4pinion .196 through the gear 195 will cause the secondary control piston 102 to rotate, and I have found that when such motions Aof rotation are given to the pistons of the control cylinders, even though the motion be very sloW lthe starting friction of the pistons and rods with reference to longitudinal motion is practically eliminated, the friction being practically constant at all times.
Referring again to the bushing 82 mounted in the bracket 80 of the primary control mechanism and to the screw threads 86 of the primary control rod 7 8 coperating with the internal threads 87 of said bushing 82, l have found the arrangement of parts there shown enables the o erator to have a very complete control o the primary control valve. By adjusting the thumb screw 85 so that the shoulder formed by the reduction in diameter of the tip is brought against the side of the bushing 82 the friction to sliding of the said bushing 82 may be adjusted to any amount desired, and when the operator desires rapid adjustments of the control valve 30', he may obtain the same by pushing or pulling on the rod 73fby means of the knob 88, thus sliding the bushing 82 longitudinally in the bracket 80, while if minute adjustments of the primary control valve 30 vbe desired, adjustments to the minutest fraction of an inch may be obtained by turning the knob 88 thereby advancin the rod 78 through its screw threads 86 an the internal threads of the bushing 82, the said bushing 82 acting as a fulcrum for the screw,
since the tip 84 of the thumb screw 85- in the key-way 83- prevents the said bushing from turning while the shoulder on the said thumb screw creates suflicient friction of thel bushing in the bracket to cause the rod 73 to advance rather than the bushing 82 to be moved. By this means it is possible to make 'either micrometric or rapid adjustments of the control valve, and thereby maintain either a micrometric or rapid control of the distant object, whereas the operation of the control rod by means of screw adjustments alone, while giving micrometric control,.
would prevent rapid control, and Ithe operation of the said control rod by pure sliding action alone would give rapid control, but make it impossible to get micrometric conl inatteso trol, since it is practicallyv impossible to manually slide a rod either steadily, slowly or to a minute amount, and as such a combination of micrometric and rapid control by one operating element is believed to 'be a new and valuable improvement in the art, ll shall claim it broadly.
Connected to the pipe 59 just above the point where it is joined by the pipe 41 is a pipe 99, and connected to the pipe 60 just above the point where it is joined by the pipe 42 is a pipe 100, the said pipes being here shown as broken, but intended to be prolonged to connect to another secondary control cylinder, similar in all respects to the cylinder 101 should it be desired to con- *80 trol a second distant object in synchronism with the movements of the primary control mechanism, and itis readily seen that should it be desired to control still other distant objects it canbe readily done by providing other secondary control mechanisms similar in all respects to that here shown and placing them at each of the objects to be controlled, all ofv theI said secondary control mechanisms being connected to the main control pipes 59 and 60.
The control system above described is not only applicable under conditions where .it is impossible to obtain a direct mechanical connection (by direct mechanical connection, l mean, a connection through rotatable or slidable rods, shaft, gears or similar elements) but also in conditions Where the maintenance of such mechanical connection involves the use of 'a considerable number of intermediate parts, such as gears, levers, etc. for going around corners, the present system is freer from lost motion introduced by the gears, joints, etc. than in the direct mecahnical connection. 105
llt is furthermore seen that by means of the control mechanism here described, it is possible to adjust the distant object to' any position between its maximum position on one side of some imaginary vzero to the same 'or some other maximum position on the other side of the said zero, therev being no steps in the adjustment, which is perfectly continuous and smooth -at all points. l
- rlihe primary control mechanism as herein described, constitutes what may be termed -for convenience a follow-up controller, in
that the movements of the primary control piston are not only in exact synchronism With the movements of the manually operated control rod, but the primary control acting on it or through leakage of the Huid operating in synchronism with said power held between it and the primary control valve, such change in position of the` primary control piston automatically moves the primary control valve which admits fluid pressure which sends the said piston to the point where it` should be, the position of theprimary control rod.
I have previously stated that the fiuid circuits of the mechanism are preferably filled with oil or water. I find that the use of such a practically incompressible fluid gives a more accurate control the greater its degree of incompressibility, ordinary grades of machine oil giving especially good results when the circuits are free from air, which otherwise results in the formation of air bubbles in the oil, rendering it quite compressible.
l. Av control mechanism comprisin an element movable by power toany position within its range of movement, a source of hydraulic power, a manually movable element having no mechanical connection thereto but controlling the movements of the said power movable element and means for causing said hydraulic power to oper-l ate said power movable element to move in exact synchronism with the movements of 'said manually movable element.
2. The combination of a primary control mechanism comprising a manually operatable element and a power operatable element, a source of hydraulic power `for operating said element, a secondary control mechanism comprising a power operatable element, and means lfor causing both the said power operatable elements to be moved in synchronism with the movements ofthe manually operatable element.
3. The combination of a source of hydraulic power, a primary control mechanism embodying a manually operatable control element and a member operated by said source of power under control of said element,l means for causing said member to move in exact synchronism with said manually operatable control element, a secondary control mechanism also operated by said source of power under control of said primary control mechanism, and means for causing said secondary control mechanism to also move in exact synchronism with said 4manually operatable control element.
4. The combination of a primary control mechanism comprising a manually operatvable element, a source 'ofl hydraulic power and a power operatable element operating in synchronism with said manually operatable element, a secondary control mechanism operatable element and means for maintainmg synchronism of operation between the said primary and said 'secondary mechaas indicated by 'i and having no mechanical connection thereto,
a power operatable control element, a source of hydraulic power for operating said element, and means for causing the said object to move in exact and continuous synchronism with motions of the said manually operatable element. v
7. The combination of a manually operatable control element, a power operated control element separated from and having no mechanical connection to said manually operatable element, a source of hydraulic power for operating said element and means for causing the said power operated control element to operate in continuous synchronism with the operation of the said manually operatable control element.
8. The combination of a manually operatable control element, an object separated from and having no mechanical connection thereto, a power operatable control element,
a source of hydraulic power for operatingV said object and element and means for causing the said object and the said power operatable control element to operate in continuous synchronism with the manually operatable control element.
9. The combination of a manually operatable control element capable of controlling power a hydraulic power operatable control element capable of controlling hydraulic power, an object separated from and having no direct mechanicalI connection to said manually operatable element, a supply of hydraulic power and means for causing said object to be moved by power in continuous synchronism with movements of sald manually operatable control element.
10. The combination of a manually opertatable control element, a power operatable element, means for causing said manually operatable element to control the'movements of said power operatable element and means for maintaining the frictional resistance to movement of the said power operatable element the same at the beginning of its movement as at other periods thereof.
11. The combination 'of an object, a manually operatable element, a hydraulic power mechanism for moving said object yon which considerable forces are acting element comprising means for moving said' object by power in continuous synchronism with motions of the said manually operatable element, 'and means for causing said object to locked in its synchronized position when sand manually operatable clement isv l@ not 1n motion.
' CHARLES MATTHEWS MANN.
R. C. MTCHELL, CHAs. A. PEARD.