US2998794A

US2998794A - Limited angular motion mechanism

Info

Publication number: US2998794A
Application number: US822770A
Authority: US
Inventors: Lennox F Beach
Original assignee: Sperry Rand Corp
Current assignee: Sperry Corp
Priority date: 1959-06-25
Filing date: 1959-06-25
Publication date: 1961-09-05
Anticipated expiration: 1978-09-05
Also published as: GB957423A

Description

Sept. 5, 1961 F. BEACH 2,998,794

LIMITED ANGULAR MOTION MECHANISM Filed June 25, 1959 3 SheetsSheet 1 INVENTOR LE/v/vox F. BEACH BY ATTOZNEY Sept. 5, 1961 F. BEACH LIMITED ANGULAR MOTION MECHANISM 3 Sheets-Sheet 2 Filed June 25, 1959 FIG.4.

ATTOR FIG. 5.

Sept. 5, 1961 L. F. BEACH 2,998,794

LIMITED ANGULAR MOTION MECHANISM Filed June 25, 1959 3 Sheets-Sheet. 3

FIGS.

INVENTOR L EN/VOX F. BEA CH BY United States Patent 2,998,794 LIMITED ANGULAR MOTION MECHANISM Lennox F. Beach, Sea Cliff, N.Y., assignor to Sperry Rand Corporation, Great Neck, N.Y., a corporation of Delaware Filed June 25, 1959, Ser. No. 822,770 11 Claims. (Cl.'1'14- -1 26) This invention relates to a mechanism having a limited angular output that is particularly adaptable to operations requiring the transfer of an element between stored and operating conditions. Such an element may be provided by the retractable fins utilized in a ships stabilization system of the character shown and described in US. application S.N. 516,662, filed June 20, 1955, by F. D. Braddon, J. H. Chadwick, n, and the present inventor. In rigged out operating condition, the extended fins of the identified application are disposed below the water line substantially normal to the hull of the ship for movement about an axis. An internal box or fore-and-aft extending storage space is provided in the hull of the ship for each of the fins. The system includes retracting means by which the fins are moved about an axis from the rigged out condition to a stowed position within the provided storage spaces or boxes. The angular range of such permitted fin movement is limited to approximately ninety degrees whether the fin is being extended or retracted.

An object of the present invention is to provide a mechanism of the character described having a single input stroking member operable to position the movable element in either its stored or operating condition.

A feature of the invention resides in the inclusion in a mechanism of the character described of a combined parallelogram linkage, crosshead, crosshead guide and ramp operative to exert a holding torque about the rigging axis of the extended movable element.

A further feature of the invention resides in the arrangement of the components of the mechanism to provide a maximum torque transfer between a stroking member and the linkage about the rigging axis as the crosshead is moved by the member across a ramp on the crosshead guide.

Another feature of the invention resides in the inclusion in a mechanism of the character described with a parallelogram linkage of two crossheads having respective straight line and short guides. The related short guide and crosshead engage only in the operating condition of the movable element.

Other objects, features and advantages of the present invention will become apparent as the description of the embodiment thereof shown in the accompanying drawings proceeds, wherein:

FIG. 1 is a plan view of the improved mechanism with a portion of the storage box in the hull in section showing the fin element in a rigged out condition for use;

FIG. 2 is a view similar to FIG. 1 showing the mechanism in the stowed position of the fin and in an inter mediate dotted line position between its travel limits;

FIG. 3 is a cross section view taken on line 33, FIG. 2;

FIG. 4 is a cross section view taken on line 44, FIG. 2;

FIG. 5 is a cross section view taken on line 55, FIG. 2; and

FIG. 6 is a cross section view taken on line 66, FIG. 2.

In the illustrative embodiment of the invention shown in the drawing, the improved mechanism is operable to move a stabilizing fin 10 or the element between stowed or stored and operating conditions with respect to the vPatented Sept. 5,. 1961 2 I hull of a ship or other body. The fin 10 shown in FIG. 1 is located in its rigged out or operating condition in which it projects from one of the sides of the ship. Suitable controls are provided such as described in the heretofore identified application to actuate the fin 10 about the stabilizing axis 11, FIG. 6, and thereby stabilizethe ship about its roll axis by the operation of an hydraulic ram 12.

As shown, the piston of the ram. 12 is operatively connected to the .fin 10 by way of connecting rod 14, crank 15 and a stub shaft 16, the ram operating the fin about axis 11 to counteract the efiect of the wave action on the ship. t V With reference particularly to FIG. 6, the stub shaft 16 of the fin 10 is mounted in'a housing 17 thatis movable about a rigging axis 18 with relation to the ship between rigged out and stowed conditions. When stowed, the fin 10 is located in a rectangularly shaped box or recess built into the side of the hull of the ship parallel to its fore-and-aft axis. A part of this wall structure is shown in FIG. 6 in relation to the hull 19 of the ship, in which walls" 20 and 21 are respectively the inside wall and the top wall of the box. The embodiment of the mechanism shown provides a limited angular output about axis 18 for an element such as fin 10 to move the same between a stored condition within the stowing box or compartment in the hull of the ship and a rigged out or extended condition for use substantially perpendicular to the hull of the ship. I In the position of the parts shown in FIG. 6, the fin 10 is condition. s

In the structure shown in FIG. 6, the housing 17 and fin .10 are angularl-y displaceable about axis 18 with relation to the top wall 21 of the water box'in the hull 19. The housing and fin elements move together as a unit about .axis 18 between the permitted travel limits, the

housing 17 being rotatably mounted in the water comhaving arms that extend between the inside wall 20 of the water box and the hull 19 of the ship. A rotatable] tube 27 within the box 24 closes the top of the housing 17 and connects the same with an open ended cylindrical crosshead guide 28 that moves'with the housing 17 and fin about axis 18. One end of the guide 28 is closed by a plate 29 which moves about axis 18 with respect to an extending portion of the fixed housing 30 of ram 12. A

suitable watertight packing gland 31 connects these parts.-

In the structure shown, the cylindrical housing 30 of the ram 12 is kept from moving vertically by the plate 29 and the parts connected thereto. The housing 30 is prevented from moving about axis 18 by a pair of arms 47 that are fixed respectively to the housing and to the wall 32, FIG. 1. A collar 34 of the ram housing extends below the guide closing top plate 29. The gland 31 permits movement of the guide 28 about axis 18 in relation to the ram housing 30. Movements of the fin 10 about its axis 11 are effected by the ram 12 by the operation of its movable element or piston connected by way of rod 35, to the crosshead 36 in guide 28, the rod 14 connected to the crosshead 36 transmitting the motion to the crank 15. The rod 35 and piston components of the ram 12 are accordingly movable about axis 18 with the fin 10,

represented in its stowed improved limited motion actuating mechanism is connected to impart angular movement to the fin about axis 18 by way of the closed guide 28 to which it is suitably fixed and the housing 17 connected to the guide. Yoke51 moves about axis '18 as the output arm of a straight line parallelogram linkage whose parallel link 52 is connected thereto by the spaced parallel links 54 and 55. A pivoted crosshead 56, FIGS. 1 and 3, at the connection between

links

52 and 54 cooperates with a straight line guide 57 extending between the end walls indicated at 58 and 59 of an open supporting structure situated above the fin box. The guide 57 is accordingly fixed to the hull of the ship to one side of the axis 18. The linkage pivot pin at the crosshead 56 is accordingly constrained to move along a line parallel to the guide 57 along which the crosshead moves. The mechanism includes a second crosshead 60 that is pivotally connected to an extension of the link 55 and is accordingly constrained to move along a line parallel to the guide 57.

The input to the mechanism is provided by motive means operatively connected to the crosshead 60. Such means may be an hydraulic servomotor or ram 61, FIG. 1, having a clevis or pivotally mounted cylinder 62 with a stroking piston 63 and a rod 64 located in substantially parallel relation to guide 57 and fixedly connected at its end to the crosshead 60. The clevis mounting provided for the cylinder 62 pivotally connects the end of the cylinder opposite the rod end to a fixed plate 65 within the hull of the ship. As shown in FIG. 1, the ram 61 is operated by hydraulic pressure supplied from a suitable pump 37 by way of a control valve 67 andthe hydraulic lines 68, 69. For the rigging out stroke of the rod 64, the ram 61 is conditioned by the valve 67 so that input pressure is supplied to the same by way of line 68, the line 69 then being connected to return fluid to a suitable sump through the valve. The adjustable valve 67 shown includes a two position arm that may be set to condition the ram in either its stowed or rigged out conditions.

As shown in FIG. 1, in the outrigged limiting position of the mechanism, the stroking rod 64 is extended to its limit as determined by the engagement of the crosshead 60 against a limit stop 77 extending from the side wall 59. In this view, the crosshead 60 also engages a short guide 78 which is spaced in parallel relation to the guide 57 and is fixedly connected to the inside wall of the hull 19 to the other side of axis 18 in the open structure above the fin compartment. In the other of the limiting positions of the mechanism, FIG. 2, the rod 64 is drawn into the cylinder 62 of the ram 61, the cross head 60 is off the short guide 78 and the crosshead 56 at the other end of the guide 57 is engaged in a locked condition by a latch 79, FIG. 5, and interlocking step 80 on the pin of the crosshead 56. A solenoid 81 is provided to release the latch 79 when energized in accordance with suitable circuitry shown in the hereinbefore identified application. The latch 79 and solenoid 81 are suitably mounted on the side wall 59 of the open structure above the fin compartment.

FIG. 2 shows the change in the relation between the yoke 51 and

links

52, 54 and 55, as the stroke rod 64 moves from a retracted to an extended position to urge the crosshead 56 along guide 57 and to urge the crosshead 60 towards the short guide 78. To relieve the power means or ram 61 of the effort required to maintain the fin 10 in its outrigged operating condition, the short guide 78 is provided with an entrant ramp 83 whose surface lies in the normal path of movement of the crosshead 60. The ramp 83 permits smooth engagement of the crosshead 60 with the short guide 78. The high surface 84 at the top of the ramp 83 is spaced in parallel relation to the guide 57. As the mechanism operates to extend the rod 64, the crosshead 60 moves in a straight line to engage the short guide 78. The crosshead 60 is then urged across the ramp to the raised surface 84 of the short guide 78. The crossheads as thusly condit 4 tioned between the guides exert a holding torque about axis 18 whose force is substantially normal to the respective guides that is transmitted by the crossheads through the parallelogram linkage to the yoke 51. At the end of the stroke of rod 64, the crosshead 60 engages the limit stop 77, moving slightly beyond a position in which the link 55 is perpendicular to the rod 64. The torque exerted by the mechanism is in a clockwise direction about the axis 18, as viewed in FIG. 1, when the fin 10 is in its outrigged condition with the stroke rod 64 of the ram 61 fully extended. Suitable means are utilized to locate the short guide 78 so that the spacing between it and the guide 57 is such as to obtain equal loading between the

crossheads

56 and 60 and their respective guides. In the improved structure, the fin 10 is maintained in its outrigged condition by the mechanism itself, without assistance of the ram 61. The size of the ram required is reduced because of the torque multiplying action of the linkage. In the fin stowing operation, the operation of the ram 61 is reversed to retract the rod 64 and thereby move the crosshead 60 down the ramp 83 free of the short guide 78. At the completion of the operation, the crosshead 56 has moved along guide 57 to a position in which the latch 79 is engaged in the step and the fin is conditioned within the stowing space or water compartment provided for the same in the hull of the ship.

T o facilitate movement of the crosshead 60 across the ramp 83 as well as to ease the withdrawal of the crosshead 60 from the short guide against the holding torque, the components are arranged so that there is a maximum torque transfer between the ram 61 and its stroking member or rod 64, and the parallelogram linkage connection therewith at the crosshead 60. This condition occurs when the link 55 connected to crosshead 6t) and the piston rod 64 are perpendicular so that the force of the ram is exerted in a direction normal to the link. The parallelogram linkage with the yoke connection to the fin, the ram or motion transferring means and the short guide with the ramp are accordingly located within the open structure above the fin box and with relation to the hull to obtain this result.

The pin and slot locking means shown in FIG. 4 is for the purpose of disabling the fin tilt mechanism under non-use conditions with the fin in a stored position. In this structure a slot 85 is provided in the crosshead 36 that receives the tapered end of a locking pin 86. The pin 86 is internally threaded and is moved to its locking position by a rotatable threaded member 87 when the engaging handle 88 is turned. The locking means is located in the air compartment provided in the hull in a position where it is readily accessible for operation.

While the invention has been described in its preferred embodiment, it is to be understood that the words which have been used are words of description rather than of limitation and that changes within the purview of the appended claims may be made without departing from the true scope and spirit of the invention in its broader aspects.

What is claimed is:

1. In a ship having a stabilizing fin and a hull with a stowing compartment for the tin, a mechanism for moving the fin about an axis between stowed and rigged out positions including a straight line parallelogram linkage mounted on the hull having a yoke operatively connected to the fin, a pivotally mounted first crosshead connected to the linkage, a straight line guide for said first crosshead fixedly connected to the hull to one side of the axis, a second pivotally mounted crosshead connected to the linkage for movement along a line parallel to the straight line guide, a short guide fixedly connected to the hull on the other side of the axis parallel to the straight line guide with a ramp in the path of the line of move ment of (the second crosshead for receiving the second crosshead with the linkage exerting a holding torque on the yoke with a force substantially normal to the respective guides, and means mounted on the hull for transferring the fin from a stowed to a rigged out position operable to move the second crosshead across the ramp and on the short parallel guide.

2. A mechanism of the character claimed in claim 1, in which said transferring means is an hydraulic servomotor having a cylinder connected to the hull by a clevis mounting, a stroking piston, and a piston rod parallel to the straight line guide connected to the second crosshead.

3. A mechanism of the character claimed in claim 1, in which said transferring means includes a stroking element connected to move the second crosshead along the line parallel to the straight line guide, the element being so arranged with respect to the linkage that as the second crosshead moves across the ramp, the link connected to the second crosshead and the stroking element pass through a condition ct maximum torque transfer with the link perpendicular to the element.

4. Means for angularly displacing an element with relation to a body between stored and operating condi tions comprising a parallelogram linkage mounted on the body having a yoke movable within limits about an axis connected to the element, a first crosshead pivotally connected to one of the links of the parallelogram linkage, a straight line guide fixedly connected to the body to one side of the axis for said first crosshead, a second crosshead pivotallyconnected to another of the links of the parallelogram linkage for movement along a line parallel to the straight line guide, a short guide fixedly connected to the body to the other side ot the axis parallel to the straight line guide with a ramp in. the path of movement of said second crosshead adapted to receive the second crosshead with the linkage exerting a holding torque on the yoke with a force substantially normal to the respective guides, and means mounted on the body for transferring the element from a stored to an operating condition operable to move the second crosshead across the ramp and on the short parallel guide.

5. Element displacing means of the character claimed in claim 4, in which said transferring means is an by draulic servomotor having a cylinder pivotally mounted on the body, a stroking piston, and a piston rod parallel to the straight line guide connected to the second crosshead.

6. Element displacing means of the character claimed in claim 4, in which said transferring means includes a stroking member connected to move the second crosshead along the line parallel to the straight line guide, the element being so arranged with respect to the linkage that as the second crosshead moves across the ramp, the link connected to the second crosshead and the stroking member pass through a condition of maximum torque transfer with the link perpendicular to the member.

7. Element displacing means of the character claimed in claim 4, including a limit stop mounted on the body for the second crosshead.

8. Element displacing means of the character claimed in claim 4, including a latch mounted on the body oper able to engage said first crosshead.

9. Means for angularly displacing an element about an axis with relation to a body between stored and operating conditions comprising a straight line parallelogram linkage mounted on the body having a yoke operatively connected to the element, a crosshead connected to the link age constrained to move along a straight line in relation to the body to one side of the axis, a short guide mounted on the body with a ramp in the path of the line move ment ot the crosshead for receiving the crosshead with the linkage exerting a holding torque on the yoke with a force substantially normal to the guide, and means mounted on the body tor transferring the element from a stored to an operating condition operable to move the crosshead across the ramp and on the short guide.

10. Means for angularly displacing an element about an axis with relation to a body between stored and operating conditions comprising a straight line parallelogram linkage mounted on the body having a yoke operatively connected to the element, a crosshead connected to the linkage constrained to'mo-ve along a straight line in relation to the body to one side of the axis, a short guide mounted on the body with a ramp in the path of the line movement of the crosshead for receiving the crosshead, and motive means mounted on the body having a stroking element connected to move the crosshead and arranged with respect to the linkage so that as the crosshead moves across the ramp the stroking element through the linkage exerts a maximum torque on the yoke.

11. In an actuating mechanism having a limited angular output about an axis with relation to a body, a straight line parallelogram linkage mounted on the body with a yoke providing the output of the mechanism, a pivotally mounted first crosshead connected to the linkage, a straight line guide for said first crosshead fixedly connected to the body to one side of the axis, a pivotally mounted second crosshead connected to the linkage to move along a line parallel to the straight line guide, a short guide for the second crosshead connected to the body to the other side of the axis, and motive means mounted on the body connected to move said second crosshead between limiting positions in one of which the crosshead is on the short guide.

References Cited in the file of this patent UNITED STATES PATENTS 2,848,971 Kollenberger Aug. 26, 1958 FOREIGN PATENTS 1,153,990 France Oct. 21, 1957 1,154,259 France Oct. 28, 1957