US2514406A - Snubbing means for catapult carriages - Google Patents

Description

July 11, 1950 L. J. MAXSON 2,514,406

SNUBBING MEANS FOR CATZPULT CARRIAGES Filed Dec. 15, 1939 3 Sheets-Sheet 1 v INVENTOR L/SLE J. MAXSON BY ,2 t v ATTORNE July 11, 1950 L. J. MAXSON SNUBBING MEANS FOR CATAPULT CARRIAGES:

Filed Dec. 15, 1939 3 Sheets-Sheet 2 INVENTOR L/SLE J. MAXSON ATToR fi July 11, 1950 1. J. MAXSON SNUBBING MEANS FOR CATAPULT CARRIAGES 3 Sheets-Sheet 5 Filed Dec. 15, 1959 INVENTOR L/SL EJ. MAXJON ATTORNEY Patented July 11, 1950 UNITED STATES PATENT OFFICE SNUBBING MEANS FDR CATAPULT CARRIAGES 13 Claims.

amended April 30, 1928; 370 O. G. 757) y tance.

Since carriages used for launching large planes often weigh several tons-since the space in which "they must be stopped is usually quite short, and since the weight of the whole catapult must,

especially aboard ship, be kept as low as possible, the problem of stopping the carriage is not an easy one to solve. The problem is further complicated by the fact that a considerable weight of cable and'moving parts set in motion by the launching action must also be stopped.

It is an object of this invention to afford a practical solution of this problem by providing a means which is rugged, simple, light in weight, and which may be utilized on the deck of a ship in a manner to protect its most vital parts from the weather and sea while requiring a, minimum of deck openings to be provided with weather coverings.

It is a further object of this invention to provide a snubbing device which will utilize the give normally present in a cable and pulley system and the elasticity of a wire cable to the fullest extent in applying the snubbing or retarding force gradually and smoothly, especially at the start of the snubbing action.

Other objects will become apparent from a consideration of the following description of a preferred embodiment of my invention and the accompanying drawings illustrating that embodiment, in which drawings:

Fig. 1 is a plan view of a catapult showing the carriage, tracks and that portion of the snubbing means which is visible above the deckof the catapult platform, the deck being partially broken away;

Fig. 2 is a side elevational view of the structure .shown in Fig. 1, plus the portion of the snubbing means located below the deck;

Fig. 3 is an enlarged plan view of a portion of the catapult showing the snubbing means in detail;

Fig. 4 is an enlarged plan view of a portion of thecatapult showing the carriage in detail;

Fig. 5 is a side elevational viewof the struc- "ture shown in Fig. 4;

Fig. 6 is'an elevational View in section of the structure shown in Fig. 5, taken along the line 6-6 of that figure; and

Figs. 7 and 8 are plan and side elevational views respectively of a section of thetrack showingan alternative anchoring means for-the snubbing cable. 1

The carriage 1 slides along a pair of'tracks 2 for which purpose it is provided withwslippers 3. A framework 4 is provided with an extension 5 projecting forwardly of the carriage'propertan'd supportinga freely rotatable pair of sheaves :6. These sheaves extend in the same horizontal plane and lie above the tracks'Z.

The carriage is propelled forward by a-pair of cables I which are kept from whipping during motion by having their weighttaken by. platesB secured beneath tracks 3 which are mounted upon I-beams 25 resting on deck 23 (see Fig. 6). These cables run to the forward end ofcthe catapult where they are led over sheaves 9 and thence toan engine 26.

The snubbing arrangement consists of :flexible means comprising a, cable rove over a systemzof sheaves and having two diverging sections which are engaged by the sheaves 6 of the carriage during its forward travel. The engagement of the .cable by the sheaves 6 causes it to be payed out, thus shortening the length of an eight-fold purchase located beneath the catapult and causing a piston to move in a hydraulic cylinder.

The snubbing cable [0 has its two bitter ends anchored in an anchoring means II which is locatedbetween the .tracksin the same horizontal plane as the sheaves 6. The two parts of the cable then diverge and pass around horizontal sheaves I3, thence around inclined fairlead sheaves I4 and down beneath thedeck through holes 24 to inclined sheaves l5 placed close together. beneath the center of the catapult. From there the parts pass to the sheaves of an'eightfold purchase Hi. One of the blocks I! of this purchase is fixed while the other blockv i8 is secured to a cross-head 2|. Secured to the-crosshead is a piston 22 which moves in hydraulic-cylinder l9 against the resistance of the fluid cOntained therein.

An alternative anchoring means'forthexsnubbing cable isshown in Figs. 7 and 8. In'this arrangement the cable is ledaround a sheave 21 anchored below the tracks but above'the platform. The two bitter ends are secured together by a coupling 28 and the two parts .ofithexlineare led through a hawse pipe 29 placed in the same relative location as the anchoring means ll shown in Fig. 2. This arrangement allows for relative movement of the two parts 1 if for any reason the action of the two sheaves 6 is unequal.

After the launching action starts the carriage travels forward with uniform acceleration until the sheaves 6 contact the two diverging parts of the cable II]. This point is shown on Fig, 3 at 5.

Further forward travel of the carriage causes the sheaves G to flex and draw together the divergent parts of the cable H! as the sheaves pass successively through the positions such as 6 and 6, resulting in drawing movement of the cable and in the paying out of the cable and shortening of the eight-fold purchase 16 against the resistance to the movement of piston 22 of the fluid in cylinder (9. The carriage is brought to rest when the sheaves B have reached the position 6 and the block I8 of the eight-fold purchase has reached the position 18 as shown on Fig. 2. Any conventional means may be used to maintain the cable taut prior to engagement of the carriage therewith.

The structure described is simple, sturdy and dependable. It will be noted that the most important parts of the snubbing mechanism are located below the deck and that the only deck openings necessary are those needed to lead the cable below decks to the eight-fold purchase.

While the disclosure of this application has been limited to one embodiment of the invention, the scope of the invention is not to be considered as restricted to this embodiment, but only by the scope and limitations of the appended claims.

The invention described herein may b manufactured and/or used by or for th Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. In a catapult device having a carriage constrained to travel along a trackway formed upon the upper surface of a platform and propelling means for said carriage; a snubbing means for arresting the travel of said carriage within a predetermined distance, said means comprising a pair of sheaves attached to said carriage and extending in a horizontal plane above said trackway, a cable having a pair of lengths extending in .the same plane as said sheaves, said lengths diverging in the direction of forward travel of said carriage, the convergent ends of said lengths being anchored above said surface, bearing means spaced laterally from said trackway, the divergent ends of said lengths being led thereabout and thence below said surface, a device capable of but resistant to movement located below said surface, the last mentioned ends of said cable being attached thereto in a manner allowing them to be payed out in response to movement of said device, whereby upon forward movement of said carriage said sheaves will engage and draw together portions of said divergent lengths thus paying out said cable and arresting movement of said cari riage.

2. In a catapult device having a carriage constrained to travel along a trackway formed upon the upper surface of a platform and propelling means for said carriage; a snubbing means for same plane as one of said sheaves and engageable thereby upon forward motion of said carriage, one end of each of said elements being anchored above said surface and adjacent said trackway, bearing means spaced laterally from saidtrackway, the other end of each of said elements being led around said bearing means and below said surface, a device capable of but resistant to movement located below said surface, the last mentioned ends of said elements being attached thereto in a manner allowing them to be payed out in response to movement of said device, whereby upon forward movement of said carriage said sheaves will engage and draw together said elements thus paying out said cable and arresting movement of said carriage.

3. In a catapult device having a carriage constrained to travel along a defined path upon the surface of a platform and propelling means for said carriage; a snubbing means for arresting the travel of said carriage within a predetermined distance, said means comprising a pair of flexible elements, one end of each of said elements being anchored above said surface and adjacent said path, a pair of bearing means located above said surface and laterally spaced from said path, the other end of each of said elements being led around one of said bearing means and thence below said surface, a member located below said surface and resisting draw on said elements, the other ends of said elements being securedthereto, and bearing means on said, carriage engageable with said elements upon forward movement of said carriage, whereby upon such engagement said last named bearing means will exert a draw upon said elements and gradually arrest the movement of said carriage.

4. In a catapult or the like, a carriage movable in a defined path, a propelling means for said carriage and a brake for said carriage comprising a flexible element with which said carriage is operatively engaged prior to arrival of the carriage at a selected point in its propelled travel at which effective braking is to occur, a bearing about which the flexible element is flexed prior to passage of said carriage beyond said point in its propelled travel, the engagement of the carriage with the flexible element being such that a draw is exerted on the flexible element after the carriage passes said point causing drawing movement of the flexible element, a member resisting draw on the flexible element, one end of said flexible element being fixed and the other thereof connected to said member, said bearing being disposed more nearly adjacent the limit of travel of the carriage under influence of the propelling means than said fixed end and said bearing being further spaced from the path of travel of the carriage in a direction transverse to said path than the point on the carriage which engages the flexible element, and means reducing the drawing movement of the flexible element effective on said member.

5. In a catapult, a carriage movable from a point of rest in a defined path to an arresting point, a propelling means for said carriage, a brake for said carriage comprising a pair of bearings spaced from said path of travel between the associated bearing and held at a point intermediate the point of rest and the bearing and so disposed that the element normally assumes between the bearing and the point where the element is held an acute angle to the path of travel of the carriage, and means on the carriage for and adapted to engage with each of said ele ments.

6. In a catapult, a carriage movable from a point of rest in a defined path to an arresting point, a propelling means for said carriage, a brake for said carriage comprising a pair of bearings spaced from said path of travel between the point of rest and the arresting point and more nearly adjacent the arresting point, draw-resisting means, a run of cable associated with each bearing, each run being connected to said drawresisting means and trained about the associated bearing and held at a point intermediate the point of rest and the bearing and so disposed that the run normally assumes between the bearing and the point where the run is held an acute angle to the path of travel of the carriage, and a rotatable element on the carriage fo and adapted to engage with each of said runs.

'7. In a catapult, a track, a carriage movable along said track, a propelling means for said carriage, and brake means for said carriage comprising: a pair of cables each anchored at one end within the confines of the track at a point remote from the starting point but also rather remote from the point of final arrest, a pair of bearings spaced transversely from the track intermediate the cable anchorage and said point of final arrest, draw-resisting means, said cables diverging from the anchorage to pas said bearings and being connected thence to said drawresisting means, and a pair of rolls at the sides of said carriage in the plane of said cables to engage the latter at a position well in advance of that of said bearings.

8. In the catapult of claim '7, said bearings disposed Well in advance of the point of final arrest, and said draw-resisting means being constructed and designed to permit said rolls to pass well beyond said bearings and thus draw said cables around said bearings into convergence towards said point of final arrest.

9. In a catapult or the like, a carriage movable in a defined path, a propelling means for said carriage and a brake for said carriage comprising a flexible element, holding means for said flexible element at a point in said defined path, said flexible element diverging laterally outwardly from said holding point in said defined path, a bearing laterally offset from said defined path and disposed forwardly of said holding point, said flexible element being trained about said bearing, and a draw resisting member connected to said flexible element, said carriage being disposed to operatively engage said laterally diverging flexible element prior to arrival of the carriage at a selected point in its propelled travel at which effective braking is to occur, said flexible element being flexed by said carriage prior to passage of said carriage beyond said point in its propelled travel, the engagement of the carriage with said flexible element being such that draw is exerted on the flexible element after the carriage passes said point causing drawing movement of the flexible element.

10. In a catapult or the like according to claim 9, means reducing the drawing movement of the flexible element effective on said draw resisting member.

11. In a catapult or the like according to claim 9, said bearing comprising a pulley and said carriage having a pulley thereon disposed to engage said flexible element.

12. In a catapult or the like, a carriage movable from a point of rest in a defined path of travel to an arresting point, a propelling means for said carriage, a brake for said carriage comprising a pair of bearings disposed one on either side of and spaced transversely from said path of travel between the point of rest and the arresting point, draw resisting means, a run of flexible means associated with each bearing, each run being connected to said draw resisting means and trained about the associated bearing and retained at a point in said defined path intermediate the point of rest and the bearing and so disposed that the run extends outwardly from said retaining point in said defined path to said bearing, and means on the carriage for and adapted to engage with each of said runs.

13. In a catapult according to claim 12, said pair of bearings being disposed nearer to said arresting point than to said point of rest.

LISLE J. MAXSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,627,614 McCully May 10, 1927 2,145,685 Chilton Jan. 31, 1939 FOREIGN PATENTS Number Country Date 258,640 Great Britain Sept. 20, 1926 465,463 Germany Sept. 18, 1928

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