US3164999A - Centrifugal speed governor - Google Patents

Description

Jan. 12, 1965 F. HEINZMANN CENTRIFUGAL SPEED GOVERNOR 2 Sheets-Sheet 1 Filed Dec. 11. 1961 5 z f. n m @f Jan. 12, 1965 F. HEINZMANN 3,164,999

CENTRIFUGAL SPEED GOVERNOR Filed Dec. 11, 1961 2 Sheets-Sheet 2 I N VENTOR FR/Tz ,qfnvz mmv nrrok NE):

United States Patent 3,164,999 CENTRIFUGAL SPEED GQVERNOR Fritz Heinzniann, Alhershausen, Kreis Goppingen, Wurttemherg, Germany Filed Dec. 11, 1961, Ser. No. 158,614 Claims priority, application Germany, Dec. 15, 1960,

11 Claims. bi. 73-550) Various centrifugal governor constructions are known and attempts are continuously made to provide governor constructions for mounting upon large diameter through shafts, wherein due to the limited space available a shorter governor length, a larger spring space, and a small internal friction are constantly sought.

It is an object of the present invention to overcome various disadvantages associated with governor constructions used heretofore and to provide a centrifugal speed governor adapted to be mounted upon a through shaft of large diameter so as to utilize increased governor power within the small space available between the through shaft and the casing enclosing the governor.

It is another object of the invention to provide a centrifugal speed governor having a small overall length, large spring space and small internal friction as compared with governor construction heretofore known.

Other and further objects of the invention will become apparent from a study of the within specification and accompanying drawing in which,

FIG. 1 shows a centrifugal governor in accordance with the invention, partly broken away and partly in section to illustrate various details,

FIG. 2 shows a schematic side view of the governor sleeve of the embodiment of FIG. 1, rotated about its vertical axis 90 degrees with respect to the positioning of the sleeve in FIGURE 1,

FIG. 3 shows a schematic top view of the governor of FIG. 1, the pivotal connection between a corresponding fly weight and the sleeve being shown, partly in section, and,

FIG. 4, FIG. 5, and FIG. 6 are perspective views of the sleeve, fiyweight, and support, respectively, of the embodiment shown in FIG. 1.

It has been found in accordance with the present invention that a centrifugal governor of increased efficiency may be provided which comprises a tubular support for coaxial mounting upon a rotatable through shaft, said support having radially extending arms at one end thereof, a tubular sleeve axially slidably disposed over the support and having a tubular end portion axially remote from said arms, peripherally spaced apart side members axially extending from the tubular end of the sleeve in the direction of and passing radially intermediate the support arms, and corresponding axially extending sleeve recesses defined by adjacent portions of the spaced apart side arms, and radially arranged flyweights outwardly movable against the force of radially positioned springs. The springs are axially positioned between the one end of said support and the sleeve tubular end, and each flyweight has a pair of lateral elements integrally con- 7 nected by an intermediate lever bridge, with the lateral elements extending peripherally to embrace concentrically a corresponding portion of the tubular support and sleeve. Each flyweight is pivotally connected with a corresponding support arm of the tubular support by means of the lever bridge, the axial extent of the lever ice bridge in the direction of the one end of the tubular support terminating at least at the corresponding axial terminus of the support arms at the one end of the support. Conveniently, the springs operatively interconnect the radially outward flyweights and the radially inward tubular support through the sleeve recesses therebetween by suitable interniediate means, and said springs axially occupy substantially the distance between the tubular end ofthe sleeve and the support arms at said one end of the tubular support. The flyweights are operatively connected to the sleeve at the side members thereof to cause axial displacement of the sleeve upon outward movement of the flyweights.

Advantageously, the tubular support is provided with an exterior wall of polygonal cross section such that the apex portions between adjacent wall planes are flattened to form low friction guiding surfaces for slid ing engagement with the corresponding portions of the tubular sleeve disposed thereover. The sleeve side members are provided suitably with stop means extending axially beyond the said one end of the support a predetermined distance and inwardly projecting over the one end of said support in order to limit the axial dis placent of the sleeve in the direction toward the opposite end of the support from said one end thereof to the predetermined distance, by impingement of the stop means against the said one end of the tubular support.

In order to suitably accommodate the radially arranged springs, the tubular support is provided with interconnecting intermediate means in the form of radially extending rods axially intermediate the ends of the support and correspondingly in the same radial planes as the support arms respectively. Thus, the springs, for example compression coil springs, may be mounted on the rods and loaded between the radially outer ends of the rods and the radially outer portions of the flyweights in the. desired manner.

With're-spect to the flyweight construction, advantageously, in accordance with the invention, each flyweight is provided with a pair of arcuately extending lateral elements, integrally connected by a central lever bridge extending radially outwardly of the lateral elements and axially there beyond in the direction toward the said one end of the tubular support. A lever member is disposedpn at least one lateral element of each pair for pivotalf coupling with the stop means of the tubular sleeve for urging the stop means and, in turn, the sleeve so as to cause axial displacement of the sleeve withrespect to the support in order to effect the governing adjustmentsj Significantly, the central lever bridge of the fly weight is provided with a radially outwardly extending bridge recess and the correspondingly support arm is radially outwardly received within the bridge recess and pivotally connected to the lever bridge thereat.

Preferably, therefore, the present invention represents "an improvement in a centrifugal governor having a tubular support for coaxial mounting upon a rotatable shaft, the support including a pair of diametrically opposed radially extending arms at one end thereof, a tubular sleeve axially slidably disposed over the tubular support, and a pair of radially arranged semi-circular flyweights correspondingly linkably connected to the support arms of the tubular support and outwardly movable against the force of radially arranged springs. The improvement specifically cornvprises providing the tubular sleeve coaxially slidably disposed over the tubular support, the sleeve having not only 'a tubular end portion axially remote from the one end of said tubular support having the radially extending arms, but also a pair of peripherally spaced apart side members axially extending from the tubular end of the sleeve in the direction of and passing radially intermediate the support arms as well as a pair of axially extending sleeve recesses defined by adjacent portions of the spaced apart side members. To effectively utilize the minimum space required for the governor, the fiyweights are axially positioned between the said one end of the tubular support and the sleeve tubular end, each flyweight having a pair of lateral arcuate elements integrally joined by a central lever bridge to form a semi-circular integral member extending peripherally so as to embrace concentrically a corresponding portion of the tubular support and sleeve. Theliiyweights are each pivotally connected with a corresponding support arm by means of the lever bridge, such that the axial extent of the lever bridge in the direction of the said one end of the supportterminates at substantially the. correspondingaxial terminus of the support arms at the said one end of the tubular support. 7 In the same way, the springs operatively interconnect as aforesaid the hyweights and the tubular support through the sleeve recesses, whereby the. springs axially occupy substantially completely the axial distance between the tubular end of the sleeve and the support arms of the tubular support. For carrying out proper governing functions, the fly- Weights are operativelyfconnected to the tubular sleeve at the side members thereof whereby to cause axial displacement of the sleeve upon outward movement of the flyweights against the force of the springs.

In accordancewith the present invention, therefore, a centrifugal governor construction is provided for mounting upon athrough shaft of large diameter, wherein the flyweights have integrally connected lever arms and radially arranged springs for particular use in those cases where the available space between the through shaft and the governor casing is small. Nevertheless, a comparatively large spring space is possible for attaining an optimum maximum governing power with minimum axial and radial dimensions of the governor.

With respect to the drawing, FIG. 1 shows a pair of flyweights 1 pivotally seated in the governor tubular support 2 by means of pivots or fulcrum pins 3. The spring supports 4 are seated in fiyweight-s 1 in the usual manner with'transverse knife edge members 4 thereof urging against flyweight transverse recesses 1' (see FIG. 5), such that the large and small diameter compression coil springs 5 and 6 urge against the spring supports 4 with their radially inner ends and urge against the nuts 7 with their radially outer ends. The nuts 7 are threaded onto the outer ends of the stay bolts 8, the inner ends of the bolts 8 being fixed to the governor tubular support 2, for example by way of threaded connections. Thus, upon outward movement of the fiyweights 1, the spring supports 4 are outwardly urged against the loaded springs 5 and 6, along the axial extent of the stay bolts 8 concentrically therewithin. The tubular sleeve 9 is outwardly disposed over the tubular support 2, and has longitudinal bores 10 (see FIG. 2) in which the flattened ends of the stop bolts ll'are slidingly fitted. Stop bolts 11 are movably seated in corresponding lever members 12 attached to the outer ends of the lateral elements of the flyweights 1. Hence, by means of the adjacent shoulders existing between the narrower diameter flattened portions of bolts 11 and the corresponding edges of the flyweight lever members 12, the stop bolts 11 are radially outwardly urged against the lever members 12 during rotation of the governor by reason of the centrifugal force, whereby stop boltsll are retained agaist outward displacement at the shoulder abutments 11' (see FIG. 3). On the other hand, in order to prevent further inward displacement of stop bolts 11, locking clips 13 are carried at the outer ends of bolts 11.

Flyweights 1 are shaped so that lateral elements 15 (see FIG. 3) embrace concentrically therewithin the tubular sleeve 9 and the tubular support 2. Thus, lateral elements 15 are arcuately shaped to circumferentially or peripherally surround sleeve 9 and support 2, the lateral elements 15 being integrally connected together by means of the central lever bridge 17 which is radially outwardly d positioned with respect to the fulcrum pin 3 connecting flyweight 1 to a corresponding support arm 16 located at one end of tubular support 2. Sleeve 9 includes a sleeve tubular end 9' remote from the end of tubular support 2 carrying the support arms 16.

As may be noted more clearly from FIG. 2, sleeve 9 is provided with a pair of side members Q" extending upwardly from the sleeve tubular end 9 in the direction toward the support arms it of tubular support 2. Corresponding recesses 26 are disposed between side members 9 of sleeve 9 in order to accommodate the springs 5 and 6 at either side of the governor. At the upper end of each side member 9" a head id is provided, each head 1% containing a longitudinal bore 10 through which a corresponding stop bolt 11 is received.

In this connection, it will be appreciated that the constructions heretofore known have always positioned the lever connection between the fiyweights and the governor support in axial direction with respect to the fulcrum pin 3 and support 2 as shown by dot and dash line 18 in FIG. 1. By providing the central lever bridge 17, radially outwardly of the support arm 15 and pin 3, the spring space in axial direction is essentially increased without adding to the length of the governor. In the same way, by providing recesses 20 (see FIG. 2) in sleeve 9, which embrace the springs 5 and 6 of each flyweight 1, the spring space in radial direction is essentially increased without adding to the diameter of the governor.

As may be appreciated from FIG. 3, sleeve 9 is not guided on the entire periphery of tubular support 2 upon which the same is disposed, but rather support 2 is given a polygonal cross section with the apexes between axially extending planes flattened to provide low friction guiding surfaces 19 for efficient sliding engagement between the sleeve 9 and the support 2.

Additionally, the radially inner stop ends 14 of the stop bolts 11 extend inwardly past the interior walls of side members h" of sleeve 9 and project over the top surface 2 of the support 2. Since stop bolts ll extend axially beyond the one end of tubular support 2 carrying support arms 16, a predetermined distance, and since stop ends 14 inwardly project over said one end of support 2, a slight distance, the axial displacement of sleeve 9 in the direction towards the opposite end of support 2 will be limited to said predetermined distance by impingement of stop ends 14 against the top surface 2' of support 2.

Turning to FIG. 4, the relationship between the sleeve tubular end 9', side walls h" and heads 16 of sleeve 9 may be seen as well as the positioning of longitudinal bores 19 through which the stop ends 14 of stop bolts 11 may be received for inwardly projecting a slight distance over the top surface of the tubular support 2 which is to be positioned concentrically therewithin.

FIG. 5 emphasizes the utilization and conservation of space in the fiyweight 1, wherein the spring opening 17' may be effectively accommodated both axially and radially with respect to the governor. Furthermore, the lateral elements 15 are shown as integrally connected With the central lever bridge 17 so that the support arms 16 of governor support 2 may be connected radially inwardly of lever bridge 17 within the radially outwardly extending bridge recess 17". By the pivotal connection between support arms 16 and central lever bridge 17, the axial extent of the flyweights 1 may accommodate fully the governor springs since the connection between the support arms 16 and the central lever bridge 17 is achieved radially outwardly of the lateral elements 15 and axially thereabove in the direction toward the support arms 16. While the central lever bridge is axially extended above the lateral elements 15, the axial dimensions of the governor are not increased since lever bridge 17 does not extend past the support arms 16. On the other hand, since lever bridge 17 does not extend radially outwardly past the springs 5 and 6, the radial extent of the governor is not increased undesirably by the particular shape ofcentral lever bridge 17. In this figure, the disposition of the transverse recesses 1 may be seen more clearly, the innermost portion of the recess extending into each lateral element 15 having a V-shaped configuration. Consequently, the laterally extending transverse knife edge member 4' secured on either side of spring support 4 will extend into the corresponding recess 1' for engagement with the flyweight thereat. The support 4 will be centrally disposed with respect to the members 4' and recesses 1', support 4 occupying the spring opening 17' which accommodates springs 5 and 6 thereat (see FIG. 1).

Accordingly, the radially inward force of springs 5 and 6 is taken up by support 4 and transmitted to the flyweight 1 via the knife edge members 4' in the corresponding recesses 1 of the lateral elements 15.

As may be seen from FIG. 6, support arms 16 extend radially outwardly from one end of governor support 2 and rods 8 upon which the springs are mounted extend in the same direction therebeneath so that the maximum axial distance between the opposite end of support 2 and the end carrying arms 16 may be used to accommodate more powerful springs, considering the overall dimensions of the governor. The guiding surfaces 19 intermediate the polygonal planes defining the exterior surface of support 2 are shown whereby the abutting portions of the inner surface of sieeve 9 may be slidingly disposed thereover with minimum frictional contact. In order to place the governor on the rotatable through shaft of comparatively large diameter, a suitable groove 2" is provided for receiving a key lock in the usual manner.

The foregoing construction achieves a shortening of the governor in axial direction by reason of the shape of central lever bridges 17 of the flyweights 1 in radial direction of the support arms 16' while recesses 20 of sleeve 9 permit an increase of the spring space in radial direction. Besides, the internal friction of the governor is reduced by reason of the low friction guiding surfaces 19 of support 2 whereby nearly the full governor power is available for use. The features of the present invention result in a centrifugal speed governor which may be placed upon a large diameter through shaft, yet the governor will possess a comparatively small length, a comparatively large spring space as well as a low degree of internal friction. Accordingly, the governor construction may be utilized for achieving great governor power within a comparatively small space between the rotating shaft and the governor casing. It will be appreciated, of course, that the instant construction contemplates not only a single-stage governor but also an adjustable twostage governor or a governor having other characteristics. In all these cases, a centrifugal speed governor is provided which may be mounted upon a comparatively large diameter through shaft, the governor having radially arranged springs and integrally connected lever arms such that the flyweights are operatively connected with the governor sleeve to attain comparatively large governor power within a small space at low internal friction, employing a comparatively small governor length, a comparatively large spring space, and a comparatively heavy load weight of the flyweights.

In this connection, among the governors having other characteristics, such as an adjustable two-stage governor which may be used in accordance with the invention, that shown in US. Patent No. 3,007,341 is particularly appropriate. The artisan will appreciate how any such governor may be modified to appropriately include the novel construction of the present invention.

What is claimed is:

l. Centrifugal governor comprising a tubular support for coaxial mounting upon a rotatable shaft, said support having radially extending arms at one end thereof, a tubular sleeve axially slidably disposed over said support and having a tubular end portion axially remote from said 6 arms, peripherally spaced apart side members axially extending from said tubular end in the direction of and passing radially intermediate the support arms and corresponding axially extending sleeve recesses defined by adjacent portions of said spaced apart side members, and radially arrangedflyweights outwardly movable against the force of radially positioned springs and axially posi-' nected with a corresponding support arm by means of i the lever bridge, the axial extent of said lever bridge in the direction of said one end of said support terminating at least at the corresponding axial terminus of the support arms at said one end of said support and the axial extent of said lever bridge in the direction of the opposite end of said support terminating at least at the corresponding axial terminus of said support arms in the direction of said opposite end, said springs operatively interconnecting said flyweights and said support through said sleeve recesses disposed radially therebetween and axially occupying substantially the distance between said tubular end and said support arms, said flyweights being operatively connected to said sleeve at said side members to cause axial displacement of said sleeve upon outward movement of said flyweights.

2. Governor according to claim'l wherein said tubular. support is provided with an exterior wall of polygonal cross section,-the apex portions between adjacent wall planes being flattened to form low friction guiding surfaces for sliding engagement with said sleeve, disposed thereover. r

3. Centrifugal governor comprising a tubular support for coaxial mounting upon a rotatable shaft, said support having radially extending arms'at one end thereof, a tubular sleeve axially slidably disposed overls'aid support and having a tubular end portion axially remote from said arms, peripherally :spaced apart side members axially extending from said tubular end in the direction of and passing radiallyintermediate the support arms and corresponding axially extending sleeve recesses defined by adjacent portions of said spaced apart side members and radially arranged flyweights outwardly movable against the force of radially, positioned springs and axially positioned between said one end of said support and said sleeve tubular end, each flyweight having a pair oflateral elements integrally connected by an intermediate lever bridge, said lateral elements extending peripherally to embrace concentrically a corresponding portion of said support and sleeve, each flyweight being pivotally connected with a corresponding support arm by means of the lever bridge, the axial extent of said lever bridge in the direction of said one end of said support terminating at least at the corresponding axial terminus of the support arms at said one end of said support, said springs operatively interconnecting said flyweights and said support through said sleeve recesses and axially occupying substantially the distance between said tubular end and said support arms, said flyweights being operatively connected to said sleeve at said side members to cause axial displacement of said sleeve upon outward movement of said flyweights, said sleeve side members being provided with stop means extending axially beyond the said one end of said support a predetermined distance and inwardly projecting over said one end of said support for limiting the same radial planes as said support arms respectively, said springs being compression coil springs mounted on said rods andloaded between the radially outer ends of said rods and the radially outer portions of said fiyweights.

5'. Governor according to claim 4'wherein each flyweight is provided with a pair of arcuately extending lateral elements integrally connected by a centrallever bridge extending radially outwardly of said lateral elements and axially therebeyond in the direction toward said one end of said support, a lever member disposed on at least one lateral element-of each pair pivotally coupled with said stop means-for urging said stop means and in turn said .sleeve to cause axial displacement of said sleeve with respect to said support.

6. Governor according to claim 5 wherein said central lever bridge is provided with a radially outwardly extending bridge recess and the corresponding support arm is radially outwardly" received within said bridge recess and pivotally connected to the lever bridge thereat.

7.. Ina centrifugal governor including a tubular support for coaxial mounting upon a rotatable shaft, said support having a pair of diametrically opposed radially extending arms at one end thereof, a tubular sleeve axially slida-bly disposed over said support, and a pair of radially arranged semi-circular fiyweights correspondingly linltably connected to said support arms and outwardly movable against the force of radially positioned springs, the im provement-which comprises providing the tubular sleeve coaxially slidably disposed over the tubular support, said sleeve having a tubular'end portion axially remote from the one end of said support having the radially extending arms, a pair of peripherally spaced apart side members axially extending from said tubular end in the direction of and passing radially intermediate said support arms and a pair of axially extending sleeve recesses defined by adjacent portions of said spaced apart side members, said fiyweights being axially positioned between said one end of said support and said sleeve tubular end, each fiyweight having a pair of lateral arcuate elements integrallyjoined by a central lever bridge to form a semifcircul-ar integral member extending peripherally to embrace concentrically a corresponding portion of said support and sleeve, each fiyweight being pivotally connected with a corresponding support arm by means of the lever bridge disposed substantially radially outwardly thereof, the axial extent of the lever bridge in the direction of said one end of said support terminating at substantially the corresponding axial terminus of thesupport arms at said one end of said support and the axial extent of said lever bridge in the direction ofv the opposite end of said support terminating at least at the corresponding axial terminus of said support arms in the direction of said opposite end, said springs operatively interconnecting said fiyweights and said support through said sleeve recesses and axially occupying substantially completely the axial distance between said tubular end and said support arms, said fly- Weights being operatively connected to said sleeve at said side members to. cause axial displacement of said sleeve upon outward movement of said fiyweights.

8. Improvement according to claim 11 wherein said tubular support is provided with an exterior wall of polygonal cross section, the apex portions between adjacent wall planes being flattened to form low friction guiding surfaces for sliding engagement with said sleeve disposed thereover.

9. In a' centrifugal governor including a tubular support for coaxial mounting upon a rotatable shaft, said support having a pair of diametrically opposed radially extending arms at one end thereof, a tubular sleeve axially slidably disposed over said support, and a pair of radially arranged semi-circular fiyweights correspondingly linkably connected to said support arms and outwardly movable against the force of radially positioned springs, the improvement which comprises providing the tubular sleeve coaxially slidably disposed over the tubular support, said sleeve having a tubular end portion axially rc mote from the one end of said support having the radially extending arms, a pair of peripherally spaced apart side members axially extending from said tubular end in the direction of and passing radially intermediate said support arms and a pair of axially extending sleeve recesses defined by adjacent portions of said spaced apart side members,

said fiyweights being axially positioned between said one end of said support and said sleeve tubular end, each fiyweight having a pair of lateral arcuate elements integrally joined by a central lever bridge to form a semi-circular integral member extending peripherally to embrace concentrically a corresponding portion of said support and sleeve, each flyweight being pivotally connected with a corresponding support arm by means of the lever bridge, the axial extent of the lever bridge in the direction of said one end of said support terminating at substantially the corresponding axial terminus of the support arms at said one end of said support, said springs operatively interconnecting said fiyweights and said support through said sleeve recesses and axially occupying substantially completely the axial distance between said tubular end and said support arms, said fiyweights being operatively connected to said sleeve at said side members to cause axial displacement of said sleeve upon outward movement of said fiyweights, said sleeve side members being provided with stop means extending axially beyond the said one end of said support a predetermined distance and inwardly projecting over said one end of said support for limiting the axial displacement of said sleeve in the direction toward the opposite end of said support to said predetermined distance by impingement of said stop means against said one end of said support.

10. Improvement according to claim 9 wherein said central lever bridge is arranged axially beyond the axial terminus of said lateral elements in the direction of said one end of said support, the radially outer terminus of said bridge being radially beyond the radially outward terminus of said lateral elements, said bridge having a radially outwardly extending bridge recess in the radially inner portion thereof, the corresponding support arm being radially outwardly received within said bridge recess and hingedly connected to said lever bridge thereat.

11. Improvement according to claim 10 wherein one lateral element of each pair is provided with a lever member coupled with said stop means for urging said Stop means and in turn said sleeve to cause axial displacement of said sleeve with respect to said support.

References Cited in the file of this patent UNITED STATES PATENTS 906,228 Harvey Dec. 8, 1908 1,971,070 Heinzmann Aug. 21, 1934 2,239,834 Williams Apr. 29, 1941 2,797,079 Heinzrnann June 25, 1957 2,846,208 Audernar Aug. 5, 1958 2,873,961 Heinzmann Feb. 17, 1959

Claims (1)

1. CENTRIFUGAL GOVERNOR COMPRISING A TUBULAR SUPPORT FOR COAXIAL MOUNTING UPON A ROTATABLE SHAFT, SAID SUPPORT HAVING RADIALLY EXTENDING ARMS AT ONE END THEREOF, A TUBULAR SLEEVE AXIALLY SLIDABLY DISPOSED OVER SAID SUPPORT AND HAVING A TUBULAR END PORTION AXIALLY REMOTE FROM SAID ARMS, PERIPHERALLY SPACED APART SIDE MEMBERS AXIALLY EXTENDING FROM SAID TUBULAR END IN THE DIRECTION OF AND PASSING RADIALLY INTERMEDIATE THE SUPPORT ARMS AND CORRESPONDING AXIALLY EXTENDING SLEEVE RECESSES DEFINED BY ADJACENT PORTIONS OF SAID SPACED APART SIDE MEMBERS, AND RADIALLY ARRANGED FLYWEIGHTS OUTWARDLY MOVABLE AGAINST THE FORCE OF RADIALLY POSITIONED SPRINGS AND AXIALLY POSITIONED BETWEEN SAID ONE END OF SAID SUPPORT AND SAID SLEEVE TUBULAR END, EACH FLYWEIGHT HAVNG A PAIR OF LATERAL ELEMENT INTERGERALLY CONNECTED BY AN INTERMEDIATE LEVER BRIDGE, SAID LATERAL ELEMENTS EXTENDING PERIPHERALLY TO EMBRANCE CONCENTRICALLY A CORRESPONDING PORTIONS OF SAID SUPPORT AND SLEEVE, EACH FLYWEIGHT BEING PIVOTALLY CONNECTED WITH A CORRESPONDING SUPPORT ARM BY MEANS OF THE LEVER BRIDGE, THE AXIAL EXTENT OF SAID LEVER BRIDGE IN

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