US2771287A - Timing actuator with hydraulic link - Google Patents

Description

Nov. 20, 1956 G. A. WINTERBURN ETAL 2,771,287

TIMING AcTuAToR WITH HYDRAULIC LINK Filed Oct. l5, 1952 2 Sheets-Sheet 1 Nov. 20, 1956 G. A. WINTERBURN ETAL 2,771,287

TIMING ACTUATOR WITH HYDRAULIC LINK 2 Sheets-Sheet 2 Filed Oct. l5, 1952 ,2 i? d 4M 3 w M f g 6 7,; w E @EN United States Patent TIMING ACTUATOR i1/1TH HYDRAUUC LINK George A. Winterburn, Putnam, Clarence B. Walworth, Rocky Hill, and Leroy E. Lawrence, Putnam, Conn.; said Walworth and said Lawrence assignors to said Winterbum Application October 15, 1952, Serial No. 314,822

10 Claims. (Cl. 264-13) This invention relates to a device for transmitting motion through combined hydraulic and magnetic links, particularly for indicating or making effective the motion or rest condition of a driving mechanism, for the purpose of supervising or controlling associated devices. lt constitutes improvements of the device according to Patent No. 2,668,043 of February 2, 1954. Its objects are similar to those of that patent.

In an important aspect the device according to the invention comprises a magnetic restraining means or coupling between the housing and driven element for yieldingly accelerating or decelerating the movement of the driven disk relative to its rest position. The magnetic circuit which provides this coupling can include permanent or electromagnetic components. The coupling will tend to accelerate or decelerate movement of the driven disk in relation to its rest position. The term accelerating will be used herein in its broad physical sense to include deceleration, denoting both speeding up and slowing down. In one important embodiment means are provided for adjusting the magnetic coupling so that the force of such acceleration can be varied. If two polarized magnets are employed provisions can be made to reverse the polarity of one of the magnets relative to the other thereby to change the coupling from attraction to repulsion or vice versa.

In a further aspect the driving means can comprise a plurality of elements such as disks, each hydraulically coupled to a driven member and each adapted to rotate independently, so that a plurality of different driving motions can be transmitted to respective driving elements, the summation of these motions producing a single motion of the driven member, and the aforesaid actuated member being operated according to the summation.

In an additional aspect the driving as well as driven members comprise a series of disks, the driving disks being separated by the driven disks. More specifically, at least one of the driven disks is supported in the chamber on bearing means and a rigid linkage connects at least two driven disks so that one coaxially supports the other.

Other objects, aspects and features will appear, in addition to those contained in the above statement of the nature and substance including some of the objects of the invention, from the following description of several typical embodiments illustrating its novel characteristics. These refer to drawings in which Fig. 1 is a front elevation of an embodiment of the invention;

Fig. 2 is a plan view of an actuator according to Fig. 1, with the housing shown in section;

Fig. 3 is a section on line 3 3 of Fig. 2;

Fig. 4 is an enlarged section on lines 4 4 of Fig. 1;

Fig. 5 is a section on line 5 5 of Fig. 1;

Figs. 6 to 1l are diagrammatic views illustrating additional embodiments and applications of the invention;

Fig. 12 is an axial section of an actuator with spring coupler; and

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Fig. 13 `is the elevation of an actuatorv with a mechanical instead of electrical take-ott.

In order to facilitate the perusal of the drawings, similar elements are sometimes designated as a group or assembly by way of decimal numbers or composite letters; in such instances, the integer or the rst letter alone refers to the entire group.

The embodiment of the present invention which is illustrated in Figs. 1 to 5 has a housing 101 which defines a chamber partially or wholly filled with a liquid of selected viscosity. A shaft 121 carries two driving disks 102.1, 102.2 fixed to the shaft and three driven or follower disks 103.1, 103.2 and 103.3 surrounding the shaft.

The housing 101 has a bottom 111 constituting a journal box in which are mounted a roller bearing 112 and a conventional sealing ring 113. At the opposite side of the housing on the cover 102, is mounted a second roller bearing 114. Bearings 112 and 114- support the shaft 121. As shown in Fig. 4, the driving disks 102 are firmly attached such as by a shrink fit, to a sleeve 122 which is similarly fastened to the shaft 121. Attached to the outer driven disks or followers 103.1 and 103.3 are the outer races of ball bearings 131 and 132, held in place by plates 133 and 134 respectively. The balls run on the sleeve 122 permitting the driven disks to rotate freely on the shaft. A sleeve 136 (Fig. 5) between the plate 1341 and the inner race of bearing 114 spaces the driven disk assembly 103 from the housing cover 102. A helical spring 116 (Figs. 2 and 4) urges the driving assembly against the sleeve 136.

The inner driven disk 103.2 is supported relatively to the two outer driven disks 103.1, 103.3 by straps 137 brazed to or otherwise rigidly connecting all three driven disks 103. The middle disk 103.2 has an opening 13S (Fig. 4) which clears the sleeve 122, the straps 137 holding the middle disk spaced from the shaft in coaxial relation with the outer driven disks. One of the driven disks, such as 103.1 carries two small permanent magnets 104 and 106 (Fig. 3) at its periphery.

These driven disks are normally held in the rest position, as shown in the figures, by a biasing means such as a weight, a magnetic coupler, or a mechanically yielding arrangement. The actuating magnet 104 or a plurality of such magnets, asymmetrically arranged, can be used as a biasing weight. Springs such as those to be described below with reference to Fig. l2 are mechanical biasing means or couplers. A preferred magnetical biasing restraining, or coupling arrangement will be described below. Mounted outside the housing 101 on the cover 102 are axially movable iron elements such as patches 105.1, 105.2 for operating an actuated member such as the switches 110.1, 110.2 (Figs. 1, 2, and 4).

The above mentioned magnet 106 (Figs. 3, 5 which is mounted on disk 103.1 cooperates with a similar magnet 107 mounted on cover 102 (Figs. 1, 5). These two magnets are in normal position of the actuator opposite each other as shown in Fig. 5 and bias or restrain housing and follower assembly 103 towards that position.

Inside the front end of the housing 101 can be arranged two stop screws 117.1 and 117.2 (Fig. 4) located in the path of the magnet 104 which is carried by the driven disk 103.1. These stops 117 limit the extent to which the driven disk assembly 103 rotates clockwise or counterclockwise from rest position. The stops are located so that the magnet 104 is stopped in a position 104g or 104b (Fig. 3) opposite one of the patches 105 associated with the actuating mechanism of switches 110. For many purposes stop screws or similar mechanical devices are unnecessary because the pull of a magnetic coupler such as 106, 107, or of spring bias means (Fig. 12) can be relied upon to perform the required limiting action.

Each of the switches 110 (Figs. 1, 4) comprises an 3 insulating post 151 carrying contact and terminal springs 252, 153 and 154. Contact spring 153 carries (see Fig. l) one of the actua-tor patches 105 and is flexibly movable so as to make contact with either spring 152 or 151i in well-known manner, as the magnet is repelled or attracted, respectively. The switch springs have extensions 155 providing terminals for connection `to respective control circuits. When the magnet 104 moves with the driven disk to either *of its displaced positions 104e or 104b (Fig. 3) the corresponding iron patch 105.1 or 105.2 is attracted so as to flex spring 153 breaking contact with 152 and making Contact with 154. Contact with spring 154 is broken when the driven disks return to rest position. Elements 104 and 105 constitute portions of a magnetic circuit whose flux depends on the relative displacement of these elements.

The stationary magnet 107 (Figs. l, 5) provides in cooperation with the magnet 106 on the driven disks an accelerating magnetic link, restraining means, or coupler between the housing and the driven or follower assembly 103. Magnet 107 is adjustably mounted on a bracket 171 by means of a screw 172 (Figs. 1 and 5). It can be set so that its south pole is opposite the north pole of the magnet 106 as shown in Fig. 5 to provide an attracting magnetic couple, or it can be rotated so that north and south poles are opposite the north and south poles respectively of the magnet 106 to provide a repelling magnetic couple, or it can be set at any intermediate position to give various degrees of attraction or repulsion.

When the magnets 106 and 107 are set to form an attracting couple, .the driven disks 103 are restrained and delayed in their movement from rest position as the driving disks start rotating. However, as soon as the driven or follower assembly leaves rest position the force of attraction will decrease according to the square law and the driven assembly 103 will then move quickly to one of its displaced positions where it is held either by one ofthe stops or by the attractive force of restraining means or coupler 106, 107 balancing the attraction between magnet 104 and one of patches 105. When the driving disks slow down the driven disks return slowly toward rest position at a rate proportional to the slowing down of the driving disk. As the driven magnet 106 approaches the fixed magnet 107 the attracting couple between these magnets increases according to the square law much more rapidly than the frictional torque of the the driver and follower components is exaggerated for the purpose of clarity.

Fig. 6 illustrates how two or more driven disks 203 can be supported solely on the linkage 237 extending between the forward driven disk 203.1 and the rearward driven disk 203.2. Where very slow rotary motions are involved the coupling between the driving disks 202 and the driven disk assembly can be increased by increasing the number of hydraulically coupled disks between the driving and driven disks. The rigid linkage 237 makes this possible and supports the additional driven disks in proper relation to other driven disks and the driving disk without the use of supports in addition to bearings hydraulic link and the driven disk is drawn into rest position with a positive snap action. When the accelerating magnets are adjusted for attraction the magnetic couple prevents the driven disk from swinging through rest position should the speed of the driving disk drop to zero abruptly.

On the other hand where it is desirable to retard instead of promote the return of the driven disks to rest position, the magnet 107 is placed by means of screw 172 (Figs. l, 5) so that a repelling magnetic couple is formed between magnets 106 and 107. This couple will then tend to hold the driven or follower assembly 103 in or near one of i-ts displaced positions until the driven assembly has fully stopped and ceased to transmit motion to the follower. The magnet 107 is of course adjusted so that it will not prevent the driven disk from assuming rest position.

It will be understood that the above-described irnprovement whose effect is inherently different from gravity or spring loaded restraining means or couplers and has often pronounced advantages, can be applied to single disk driver and follower links.

Further to illustrate the nature of the invention, by way of additional practical embodiments, and modes of use, reference is now made to the diagrammatic views of Figs. 6 to l1. In these views the various parts of the hydraulic actuator are shown in schematic form andl the spacing between the various parts, for instance between 231, 232, and 212, 214.

Fig. 7 illustrates an embodiment of the present invention in which a plurality of different driving motions can be combined to produce a single motion of a driven element. in this embodiment three sets of driving disks 202.1, 202.2, 202.3 are independently mounted on the housing with separate rotatory means such as shafts 221.1, 221.2 and 221.3, respectively. Shaft 221.2 com,- prises a tube spaced from the shaft 221.1 by suitable bearing means 214.1 and 214.2 and supported in the housing 201 by a bearing 212.1. The third driving disk 202.3 is fastened to shaft 221.3 supported in similar manner by suitable bearing means such as schematically indicated at 212.2. Sealing means are provided to retain the huid within the housing, in the manner described with reference to Fig. 2. A rigid linkage 237 connects driven disks 203.1, 203.2, 203.3 and 203.4 in the manner described with reference to Figs. 2 and l2, the disks 203.1 and 203.3 running on shafts 221.3 and 221.1 by means of bearings 212.5 and 212.4, respectively. Where a plurality of driving disks are employed in this manner the intermediate driven disks serve to isolate the several different hydraulic couples between the driven disk structures respectively, presenting turbulence with indefinite translation effects between the couples.

When it is desired to correlate several external mechanisms which transmit different speeds to the respective driving disks i-t is possible according to the invention to adjust a coupling force such as the tension of the spring 209 and the coupling force of magnetic elements such as 206 and 207 to compensate for the difference in speeds. For example, should two external mechanisms be turning shafts 221.2 and 221.3 in a counterclockwise direction and the third shaft 221.1 in clockwise direction as indicated in Fig. 7, and should it be desired to aotuate a fourth external mechanism when the first three have reached predetermined speeds, the tension of the spring 209 can be set so that it tends to displace the driven assembly 203 from rest position. The magnetic couple provided by magnets 106 and 107 can be adjusted to counteract this unbalance while the driven member is in or close to rest position. Assuming that shafts 221.1, 221.2 and 221.3 are driven at approximately the same speed, shafts 221.2 and 221.3 will tend to overcome the torque transmitted hydraulically to the driven disk by shaft 221.1 but the unbalance afforded by the spring will overcome this tendency so that the driven member is held at rest position until the shafts approach the. predetermined speed when the tendency will .be sucient to overcome the attractive force of the magnetic couple and move the driven member from rest position. Thereafter the force of ,the magnetic couple will dropmore rapidly than the increased tension on the spring and allow the tension of the spring plus the movement of the driving disk to move the driven member 203 with magnet 104 into operating relation with the magnetic element 105 of the actuated device 110.

A simpler but particularly practical embodiment of the principle illustrated by Fig. 7 is shown in Fig. 8. In this figure, two motors M1, M2 with alignedshafts 221.8, 221,9 transmit their motion .to driving disks 202.8,

202.9 respectively, which disks are fastened to respective shafts. A driven disk 203.9 floats on the shafts, for example by means of a sleeve241 which is fast to one of the shafts but slides over the other, and a bearing 212.9 mounted on the sleeve. Actuating magnets 104, 105 and coupler magnets 106, 107 are mounted on follower 203.9 and fluid containing housing 201 respectively. In this arrangement, the driven element 203 responds to a differential of the two motor speeds. The senstitivity of response, the direction responded to, and the timing of the response can be selected and adjusted by appropriately placing the coupling and actuating units 104, 105 and 106, 107 respectively, in the above described manner. By providing two actuated elements, such as indicated at 105.1, 105.2 of Figs. l to 5, with the hydraulic and magnetic coupling forces properly adjusted, synchronization and various other speed relations of the two motors can be detected and controlled.

Fig. 9 illustrates the magnetic couple between the accelerating magnet 207 on the housing and a magnetic element 206 on the driven member 203, by varying the gap between the magnets. The magnet 207 is mounted at the end of a spindle 251 with knob 252 and xating nut 253. The spindle is threaded into the top of a cap 255 which is attached to the casing 201. The gap between magnets 206 and 207, is adjusted by screwing the magnet 207 in or out against the pressure of spring 256. The attraction of the respective poles makes axially guiding means unnecessary in most instances, but such guides can easily be provided if necessary.

Fig. l illustrates a modification in which the magnetic element 260 comprises an electromagnet 261 having a iield coil 262. The coil 262 is energized by a source of direct current 265 connected in series with a rheostat 266. A double pole, double throw switch 267 permits reversal of the polarity of the current energizing the coil. The rheostat 266 permits adjustment of the current through the coil so that a magnet-ic circuit of varying strength and polarity can be produced in magnets 206 and 261. The adjustable magnet can be located on the driven member, in which case it has to be supplied by yielding leads or slip rings.

Fig. ll illustrates a further modification for varying the strength of the magnetic couple of a magnetic biasing arrangement. The driven assembly 203 carries a permanent magnet 206 and mounted on a bracket 270 attached to the housing 201 is a magnetic element 271. This magnetic element is attached to a slider 272 with set screw 273 which may be adjusted along the bracket 270 to vary the gap between the elements 206 and 271, as indicated at 271g of Fig. ll.

As shown in Fig. 12 the accelerating magnets 106 and 107 of Figs. 3 and 4 may be used in cooperation with a coil spring 231 which however can also be used alone. The coil spring 201 is attached at each end to screws 282 mounted in threaded sockets 283 in the housing 101. The screws 282 can be fixed in various positions relatively to the housing by nuts 284. The middle portion of the spring 281 which may have two or more coils is attached to the driven assembly 103 by a clamping screw 286. The yielding force with which the spring 281 urges the disk assembly to the rest position shown in Fig. l2 can be increased or decreased by moving the screws 282 in and out of the housing 101. In this manner the yielding force of the spring which increases slightly when the driven disk rotates may be balanced against the accelerating force of the magnetic coupling magnets 106 and 107. 1f the magnetic couple is attracting then the effect of the spring and the magnetic couple is additive, but if the magnetic couple is repelling then the combined effect of spring and couple is subtractive. In applications where it is desired to delay the movement of the driven member into rest position until the driving member has fully stopped, the magnetic couple is made repellant. in this case the spring urges the driven disk towards rest position. as the driving disk is slowed down at a rate proportional to the slowing down of the driving disk. However, as the driven disk approaches rest position the magnetic couple will increase in force and delay the driven disk from assuming rest position until the driving disk has fully stopped.

Fig. 13 illustrates uses of actuators according to the invention, other than in electric circuits. This figure shows the actuator of Fig. l, with the switch replaced by an actuating rocker 301 pivoted at bracket 302 fastened to the wall 26 of the actuator housing. The rocker 301 carries at one end a magnet 305 which cooperates with magnet 7 of the driven or follower assembly in the above kdescribed manner. The other end of the rocker rests on the needle 306 of an air valve 311 which is for example part of a control system for hazardous applications, with a duct 312 constantly supplying compressed air and a switch 315 responding to increased air pressure. With shaft 3 rotating during normal operation, magnet 7 is removed from magnet 305, rocker arm 301 is free and needle 306 permits vthe bleeding of air which condition corresponds to the normal position of switch 315. When the shaft 3 slows down below a predetermined speed, magnet 7 comes opposite magnet or plug 305 which is attracted and closes the needle valve. The bleeding of air is stopped and switch 315 is operated.

it wiil now be evident that actuators according to the invention are very Versatile. Only a few practical applications could be described in some detail by way 0f illustration, but many others are possible and attainable without or only slight adjustment of the basic actuator structure. Among these applications are time delay, speed limiting, indication of rest or movement of machine elements, indication and discrimination of direction of rotation, indication of faulty operation such as stalling or excess speedof remote or concealed machinery, interlocking of normally stationary and moving elements if desired with several delays stepped by appropriate setting of the delaying forces of several acuators, interlocking of motor starters for protection against back spin, overrunning control, indication of breaks or runouts on feeding devices and stoppage of such devices, prevention of the application of reverse power before complete stoppage is reached, counting to indicate the number of starts and stops of equipment, making time studies, plugging and jogging. Further advantages of devices according to the invention are snap action if desired, self-lubrication, high speed operation well above 5,000 R. P. M. at temperatures between 20 F., and +250 F., due to possibility of comparatively inert iiuids such as silicon oil, easy adjustability if desired by remote electrical control, and protection against vapors and dust due to complete enclosure.

It should be understood that the present disclosure is for the purpose of illustration only and that the invention includes all modifications and equivalents which fall within the scope of the appended claims.

We claim:

l. An actuator comprising a housing enclosing a charnber for holding a viscous liquid; a plurality of driving elements; a driven member movably mounted in said chamber, said element and member respectively having riving and driven portions adjacent to each other and adapted to be hydraulically coupled by said liquid; an

7 that said driving element and driven member comprise a plurality of essentially parallel disks.

3. Actuator according to claim 1 wherein said coupling elements constitute a magnetic circuit.

4. An actuator comprising a housing enclosing a chamber for holding a viscous liquid, two shafts rotatably mounted on said housing and extending into said chamber, a driving disk rotatably carried on each of said shafts, a driven disk adjacent said driving disks, said liquid affording a hydraulic coupling between respective pairs of driving and driven disks, bearing means for rotatably supporting said driven disk, an actuated member, magnetic elements disposed on said member and said driven disk respectively to constitute a magnetic coupling which is varied by movement of said driven disk to operate said actuated member, the summation of the motions of said shafts producing a single motion of 'said driving member, to operate said actuated member according to said summation.

5. An actuator comprising a housing enclosing a chamber for holding a viscous liquid, a driving element and a driven member rotatably mounted in said chamber with driving and driven portions adjacent to each other and adapted to be hydraulically coupled by said liquid so that rotation of the driving element produces movement of the driven member; means for urging said driven member towards a position of rest relatively to said housing; an actuated member on said housing; means for operating the actuated member upon movement of the driven member; and magnetic restraining means including magnetic circuit means having one branch portion mounted on said driven member and another branch portion on said housing outside of said chamber adjacent to the path of said rst branch portion, for applying a yielding force between driven member and housing to restrain the movement of the driven member relatively to said rest position; whereby the housing separates the two branch portions and the restraining force can be controlled by controlling the branch portion on the housing.

8 6. Actuator according to claim 5 characterizedin that said branch portions are essentially U-shaped with their ends facing each other, and further including means for varying the distance between said portions to vary said restraining force.

7. Actuator according to claim 5 characterized in that said magnetic circuit includes an electromagnetic member and means for adjusting the field of said electromag# netic member.

8. Actuator according to claim 5 characterized in that said restraining means comprises two polarized magnets, and means for adjusting one of said branches in a sense to reverse its polarity relative to the other branch, in order to vary said restraining force from attraction to repulsion.

9. Actuator according to claim 8 further characterized in that said one branch is continuously adjustable so that said force can be gradually changed.

l0. Actuator according to claim 5 characterized in that said driving element comprises a plurality of disks. each disk being hydraulically coupled to the driven member, and the disks of the driving element being mounted for being individually driven.

References Cited in the tile of this patent UNITED STATES PATENTS 1,209,359 Tesla Dec. 19, 1916 2,096,069 Seiden Oct. 19, 1937 2,099,849 Holmes Nov. 23, 1937 2,245,596 Lindberg June 17, 1941 2,294,606 Newell Sept. 1, 1942 2,488,629 Kline Nov. 22, 1949 2,524,261 Kaminky Oct. 3, 1950 2,600,011 MacDonald et al June 10, 1952 2,600,309 MacDonald et al June 10, 1952 2,629,859 Taylor Feb. 24, 1953 FOREIGN PATENTS 268,510 Italy Oct. 18, 1929

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