US1676994A - Control mechanism - Google Patents

Description

July 1o, 1928. 1,676,994

R. C. LAMOND CONTROL MEGHANISM vr11mm may 1o, 1924 2 sheets-sheet 1 July 1o, 1928.

R. C. LAMOND CONTROL MECHANISM` Filed May 10, 1934 PW l Patented July l0, 1928.

UNITEDST'ATES PATENT OFFICE;

ROBERT CRAIG LAMOND, 0F PHILADELPHIA, PENNSYLVANIA, ASSIGNOR T0 AMERI- CAN ENGINEERING COMPANY, 0F PHILADELPHIA, PENNSYLVANIA,A CORPORA- TION OF PENNSYLVANIA,

CONTROL MECHANISM.

Application filed May 10,

My invention relates to control mechanism and it has particular relation to such mechanisms as are applicable to limit or reversing devices.

In its broad aspect, an important object of my invention is to provide means for automatically operating a limit or reversing device, said means being characterized by its simplicity of design, durableness of construction and positiveness of operation.

A more specific object of my invention 1s to provide controlling mechanism embodying a main control device which is adapted to be tripped and rc-set automatically 1n accor-:lance with the slack lin a power-transmitting clement.

Another object of my invention is to provide a novel system of control comprising a power device, apparatus to be actuated thereby, means for so operatively associating the `same that a slack portion appears when the torce thereon falls below a predetermined value, control means for said power device, and actuating means for said control means operable in accordance with the variations in said slack.

A further object of my invention is to provide-means whereby a substantially constant tension may be maintaied in an operating cable as a structure secured thereto moves withthe rise and lall of a stream.

`Vith these and other objects and applications in mind, my invention further consists in the details of construction and. operation, hereinafter described and claimed and illustrated in the accompanying drawings, wherein:

Fig. 1 is a side elevational view of a ferry bridge and its operating mechanism, illustrating one application ol" my invention;

Fig. 2 is a top plan view of the structure of Fig. 1; and

Figs. 3 and 4 are detail side and end elevational views, respectively, of the limitswitch operating mechanism.

In theillustrated form of embodiment of .my invention shown in Figs. 1 to 4, inclusive, a pair of spaced vertically extending frame members 1 and 2 support on their upper ends a pair of spaced horizontally extending members 3 and 4, all of which constitutes a so-called gallows trame which is mounted on a suitable supporting structure or foundation 5 positioned near the enter end of a ferry bridge 6, the inner end of which may 1924. Serial No. 712,494.

be Vhinged to a supporting structure (not shown) in the usual manner, whereby the outer end of the "bridge (l may be moved vertically, at will, or in accordance with the rise and fall ol" a body of water.

A desired portion of theweight of the outer end of the ferry bridge 6, say, for example, 9505, may be counter-balanced by weights 7 and 8 which are respectively hung 'from the cables 9 and 11. The cables-9 and 11 respectively pass over sheaves 12 and 13, which are mounted on the upper supporting frame work 3 4, and extend downwardly to dead-end supporting elements 14 and 15 secured on the opposite sides of theV ferry bridge 6. Y

The outer end of the bridge 6 may 'be raised and lowered, at will, bymeans of an electric motor 16 having an operative connection through suitable gearing 17 18 with a winding drum 19which is preferably disposed in proximity to the center of the upper supporting structure 3 4. The motor 16 may be manually controlled by means of a controller of the usual type and associated circuits (not shown), wherein opposite movements of the controller from a neutral position cause the respective energization of said circuits and consequent reversals in the direction of operation ofthe winding drum 19.

Cables 21 and 22 respectively extend in opposite directions from the winding drum 19 over sheaves 23 and 24, which are mounted on the upper supporting structure 3 4, and under sheaves 25 and 26, which are secured by sheave saddles '28 to the opposite sides of the ferry bridge 6. From the sheaves v25 and 26, the cables 21 and 22 pass upwardly and over sheaves 29 and 31, which are mounted on the upper supporting strncture 3 4, then down under traveling sheaves 32 and 33, respectively terminating on dead- end supporting elements 34 and 35. The traveling sheaves 32 and 33 may be revolubly mounted on shafts 36 36, the ends of which are vertically guided by pairs of spaced members 37 and 38 (Figs. 3 and 4). v

W hen itis desired to raise the outer end of the hinged bridge 6, the controller for the driving motor 16 is moved into the raising position, thereby causing the drum 19 to absorb or decrease the slack in the cables 21 and 22 and finally resulting in the actuation oi the sheaves 32 and 33 into their upper maximum position shown in ljig. l. The continued operation or' the winding drum V19 then causes the lifting of the outer end oi the hinged bridge 6 and this movement continues so long as the motor controller is held in the raising position.

When the motor controller is actuated into the lowering position, the drum 19 moves to unwind the cables 21 and 22, so that the outer end of the hinged bridge 6 is low ered until strong backs 39 and 40, which extend from the outer end of the bridge 6, rest on the deck of the boat to be moored (not shown). Assuming that the controller is retained in the loweringY position, the driving motor 16 continues to unwind the cables 2l and 22, causing the same to become slack since the load of the bridge 6 has been removed therefrom. As hereinbefore noted, my invention contemplates means for centralizing the slack appearing in the cables 21 and 22 and it further contemplates an automatic limit switch 41 adapted to be operated in accordance with the variations in the length of the slack portion of one of the cables 21 and 22, say the latter, whereby the driving motor 16 may be automatically controlled. To this end, l provide the above-mentioned traveling sheaves 32 and 33 which are so weighted that they centi-alize such slack` as may appear in the cables 21 and 22.

The automatic limit switch 41 (Figs. 3 and 4) for electing the above-noted desired result includes trip mechanism 42 which is operatively associated with the traveling sheave 33 only. The trip mechanism 42 is so related to the limit switch 41 that the solid and dot-and-dash line positions thereof in Fig. 3 represent open and closed switch positions, respectively. The trip mechanism 42 comprises a switch-operating shaft 43 which'provides a mounting for a member 44 having oppositely extending arms 45 and 46. The operating member 44 is caused to move normally into the circuit closing dot-and-dash line position by a weighted member 47 carried on the outer end ot' the arm 45.

The movement of the switch-operating member 44 from the open solid-line position to the closed dot-anddash line position may be prevented by means of a locking lever 48 pivotally mounted on an upper side of the arm '46. The locking lever 48 releasably engages a shoulder' 49 formed on one ot' the movable sheave guides 38 with a force proportional to that of the said weighted meinber 47. The locking lever 48 may be actuated clear oi' the retaining shoulder 49 by means of a releasing lever 51 which is rigidly secured to a shaft 52 common to the locking lever 48. The releasing lever 51 is preferably weighted so that the locking lever 48 may be normally returned from an inell'eeA tive position, which it assumes when it is actuated clear of the shoulder 49, to the eli'ective position shown in solid-line in Fig. 3 of the drawine'. The releasing lever 5l is of such length that it may be engaged by an operating pin 53, which projects from one end oi the shea-ve shaft 56, only when the latter is moved vertically upwardly and the switch-operating member 44 is in the locked ciicuit opening position. The releasing lever .51 and the locking lever 4b' may be retained in the dotand-dash line position by means or' a lug b4 on the member 44 which engages a shoulder b5 formed on the releasing lever 51.

When the operating pin 53 is moved downwardly in accordance with an increase in the slack of the cable 22, the pin 53 finally engages a projecting portion 56 ol the arm 46, causing the Snitch-operating member 44 to move from the circuit-closing posit-ion shown in dotanddash lines in lfig. 8 to the circuit-opening position, shown in solid-line. ln order that the operating pin 53 may pass by the extension 56 when moved vertically upwardly without causing the operation of the member 44, l pivot-.illy mount the extension :36 on the outer end of the. arm 46 and provide a projecting lug portion 57 on the member 56 which is adapted to engage a shoulder 5b i'ormed on the under side oi' the member 44.

ln operation, assuming the traveling sheaves 32 and 33 at the upper limit of their stroke and the switch-operating member 44 in its circuit-closing position, a movement of the motor controller into the lowering position causes a downward movement of the outer cud ol the bridge 6 until the strong backs 39 and 40 thereof rest on the boat or other apparatus (not shown) to be moored to the i'erry bridge 6. The continued operation of the motor 16 thereupon causes slack in the cables 2l and 22 which is centralized by the weighted guiding sheaves 32 and As the slack in the cables 21 and 22 increases, the sheaves 82 and 33 move downwardly, linally resulting in the operating pin 53 engaging the hinged arm 56 and actuating the movable member 44 from the circuit-closing position to the locked circuit-opening position shown in solid-line in Fig. 3, whereupon the motor 16 becomes inoperative.

When the operating controller of the motor 16 is moved into the raising position, the motor 16 immediately becomes ellcetive to cause the drum 19 to absorb the slack in the cables 21 and 22, thereby resulting in an upward vertical movement of the sheaves 32 and 33 as well as the operating pin 53. Since the projecting arm 56 is so mounted on the arm 46 of the switch-actuating me1nber 44 that it may be actuated upwardly llU independently of the latter, the pin 53 moves upwardly without disturbing the member 44 until it engages the releasing lever 51.

The continued upward movement of the pin 53 causes the releasing lever 5l to move upwardly, thereby actuating the locking lever 48 out of engagement with the retaining shoulder 49. The-switch-operating member 44 now moves under the force of the weighted member 47 from the circuit-opening position to theCircuit-closing position, the hinged extension 56 being correspondingly moved upwardly into a osition where it may be again engaged by t e operating pin 53 upon a downward movement of the same. The sheaves 32 and 33 continue their upward movement until they reach the limit of their stroke, 'whereupon the outer end of the bridge 6 is raised. `When the outer end oi the ferry bridge 6 israised to the desired height, the controller of the driving motor 16 actuated from the raising position to the neutral position to hold the bridge 6 in the desired position. If the motor controller is again moved :into the lowering position, the foregoing cycle is repeated, the operating-pin 53 again actuating the switch-operating lever 44 from the circuit-closing position to the locked circuit-opening position, to eilect the inoperation of the driving motor 16.

A further valuable feature of my invention is the maintaining substantially confill .st-ant over a long period of time the tension in thc cables 2l and 22, regardless of a fall in tide. To eilect this desired result, the ,fontrollerof the motor 16 is moved into the lowering position, causing the bridge 6 to tall until the strong backs39 and 40 engage the deck of a boat to be moored, The continued operation of the motor 16 causes the drum 19 to unwind until the pin 53 engages the switch-operating lever 44, actuating the latter from the circuit-closing position to the circuit-opening position, whereupon thc motor 16 becomes'ineifective.

As the boat and ferry bridge 6 continue to descend with the falling tide, the traveling shcavis 32 and 33 and, consequently the pin 53, move upwardly until the latter engages the lock releasing lever 51, permitting the weighted member 47 to actuate the switchoperating member 44 into its circuit-closing position. The motor 16 then continues to unwind until the .pin 53 is again moved downwardly sutlicient to cause a movement ot the switch-actuating member 44 to the circuit-opening position. This icycle, continues so long as the bridge 6 descends with the tide. In arranging my apparatus for rising tides, the controller for the motor 16 is moved into the raising position and the pairs ot traveling sheave guides 37 and 38 are made of such length that the sheaves 32 and 33 may descend 'an amount sufficient to accommodate for the maximum high tide.

While I have shown only one form of embodiment of my invention, for the purpose of describing the same and illustrating its principles et' construction and operation, it is apparent that various changes and modifications may be made therein, Without departing from the spirit ot' my invention as t'or instance the use of any form of slack operated controlling device or vthc power source 16. I desire, therefore, that only such liniitations shall be imposed thereon as are indicated in the appended claims or as are demanded by the prior art.

I claim:

1. A power device, bridge apparatus to be actuated thereby, means including a cable tor operatively associatinflr said device and said bridge apparatus, means t'or centralizing the slack in said cable appearing when the strain in the latter falls below a predetermined value, control means, and means whereby said slack may. operate said control means.

2. Bridge operating mechanism comprising a power device, bridge apparatus to be actuated thereby, means including a cable i'or so operatively associating said device and said bridge apparatus that a slack portion appears in said cable when thestrain therein falls below a predetermined value control means, and yan actuating element for said control means` responsive to variations in said slack portion. i

3. A power device, a movable bridge, a cable for operatively associating said device and said bridge, weighted guiding means for ccntralizing the slackin said cable appea ring under predetern'iined operating conditions, and control means adapted to be actuated in accordance with variations in said slack, said control means determining the effectiveness ot' said power device.

4. In a system of control for a. ferry bridge, the combination with a power device and bridge apparatus adapted to be actuated thereby, of mea-ns including a cable for operatively associating said device and said bridge apparatus, weighted means for centralizing the slack in said cable appearing when the strain in the latter falls below a predetermined value, and control means responsive to variations in said slack.

5. In combination, a power device, a movable bridge means including a cable for operactively associating said device and said bridge, a traveling sheave adapted to centralize the slack in said cable appearing under predetermined operating conditions, control means for said power device, and operating mechanism for said control means adapted to be tripped and re-set by said traveling sheave, whereby said power device may be successively rendered ineffective and effective.

G. A system of control comprising a power device, a terry bridge means including a cable for operatively associating said device and said ferry bridge, weighted means for centralizing the slack appearing in said cable under certain operating conditions, control means for said power device, and mechanism for actuating said control means in accordance Vwith the direction of movement of said weighted means.

T. Apparatus of the class described comprising a bridge structure to be moved, a power device, a cable for operatively associating said bridge structure and said device, a traveling sheave movable in accordance with the slack appearing in said cable nnder certain conditions of operation, and a controlling device for said power device adapted to be operated by said traveling shcave. f

8. In combination, a structure to which a boat is to he moored, a driving drum, powertransmitting means including a cable operatively associating said structure and said drum, and means operable in accordance with the movement ot said drum for controlling the operation ot the latter.

9. A structure positioned to fall with the tide, ay power device, cable means operatively associating said device and said structure, whereby the latter may be lowered independent of the tide, and means controlled by said cable means for automatically maintaining a predetermined slack in' said cable means as said structure falls with the tide.

l0. 1n combination, a structure positioned to rise with the tide, a power device, liifting cables operatively associating said device and said tructul'e, and means whereby the amount oi slack in said cable may be maintained within certain limits as said structure rises with the tide.

11. A system tor a ferry bridge conipr1s1ng a sheave movably mounted 1n spaced guides, a control member movable from one position to another, means for exerting a force on said control member tending to move the latter from one of said positions to another, locking means for releasably rctaining said member in one of said positions, one ot said guides constituting retaining means for said locking means, and releasing means positioned to be actuated by said sheave when said sheave is moved in one direction only.

l2. Bridge control mechanism comprising a sheave movably mounted in spaced guides, a. pivoted member provided with oppositely extending arms, means ior exerting a force on one of said arms, a locking lever mov ably positioned on the other of said arms, one of said guides being provided with a retaining shoulder for said locking lever, and a releasing lever for said locking lever positioned to be actuated by said sheave when the latter is moved in one direction, said member being actuated by said sheave when the latter is moved in another direc tion.

13. In combination, a power device, a movable bridge adapted to be actuated thereby relative to a supporting surface, means including a cable for operatively associating said device and said bridge, whereby the latter may be actuated relative to said suriace, said cable having a slack portion appearing upon the continued operation of said power device after said bridge has engaged said supporting surface, a controlling device fer said power device, and means whereby said slack portion may control said power device.

ROBERT CRAIG LAMoND.

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