US1190046A - Automatic davit. - Google Patents

Description

R. TJADER.

AUTOMATIC DAVIT. I

APPLICATION FILED DEC.12. 1914.

1,1 90,046. Patented July 4, 1911s.

4 SHEETSSHEET I.

Em i

WITNESSES h INOII/QAILTOH t I 1c ar adeZ W rr .4 TTUfi/VEXS R. TJADER.

AUTOMATIC DAVIT.

APPLICATION FILED DEC. 12. 1914.

WITNESSES q- I INVENTOR 25% S dd.-: p v v ATTORNEYS Patented July 4, 1916.

4 SHEETS-SHEET 2- R. TJADER.

AUTOMATIC DAVIT.

APPLICATION FILED DEC. 12. 1914.

1 1 90,046. Patented July 4, 1916.

4 SHEETSSHEET 3- WITNESSES g J l/VI/E/YTOI? Richard T 'ader By 7/m W 4UOBIVEKS R. TJADER.

AUTOMATIC DAVIT.

APPLICATION FILED DEC. 12, 1914.

Patented July #1, 191

4 SHEETS SHEET 4.

INVENTOf? Rickard finder WI T/VESSES:

A TTOR/VE V8 ters Patent of the RICHARD TJADER, OF NEW YORK, N. Y. I

AUTOMATIC DAVIE.

Specificationof Letters Patent.

Patented July 4, 1916.

Application filed December 12, 1914. Serial No. 876,802.

T 0 all whom it may concern Be it known that I, RICHARD TJADnR, a citizen of the United States, and a resident of the city ofNew York, borough of Manhattan, in the county and State of New York, have invented a new and Improved Automatic Davit, of which the following is a full, clear, and exact description.

This invention relates to mechanlsm of the character described and claimed in Let- United States No. 1,116,956, issued to me on November 10, 1914.

Among the objects of the invention is to improve davit construction in a number of specific and important particulars, among which is the provision of an inclined chair or support for each of the davit arms or quadrants, and whereby the quadrants may gravitate outwardly promptly when released.

Another object of the invention is to s mplify and improve the manner of anchoring each of the davit arms or quadrants to its Chair.

A further object of the invention is to provide interlocking devices between the davit arms and the chair auxiliary to the aforesaid anchoring devices, said interlocking members including a. lug or toe formed on one of the members and adapted to enter a corr spondingly formed socket in the other mem er.

A further object of this improvement is to provide a starting device for the purpose of initiating the outwardly rolling ac- 7 tion of the davit arm's even though said arms may be inclined inwardly to a considerable extent because of a list of the ship or otherwise.

A still further object of the improvement is to simplify, strengthen and otherwise improve the construction of the head of each of the davit arms, whereby, among other advantages, the normal weight of the lifeboat is borne by the davit arms and not by the controlling cables.

A still further object of the invention is to provide means for checking or holding the davit'arms at any desired outward inclin'ation without interfering with the main controlling cables, making it possible to bring a lifeboat very close to the gunwale or for permitting it to swing at considerable distance beyond the ship,

Another object of the invention is to improve the drum construction whereby the various controlling devices above referred" invention will hereinafter be more fully described and claimed and illustrated in the drawings forming a part of this specification in which like characters of reference indicate corresponding parts in all the views and in whic Figure l is an elevation of the left hand end of my improved construction, full lines indicating the normal housed position of two lifeboats, and dotted lines indicating changed positions of certain of the parts; Fig. 2 is a side elevation of the same, the observer facing the sea; Fig. 3 is an elevation of the outer face of one of the head portions of a davit arm with the shackle in normal position; Fig. 4 is a vertical longitudinal section of the drum mechanism; Fig. 5 is a vertical sectional detail on the line 5-5 of Fig. 1; Fig. 6 is a perspective view of the outer end of one of the rocker members; Fig. 7 is a perspective view of the lower portion of one of the shackle hangers;

.Fig. 8 is adetail view of one of the chair effect the operation of this improvement, it

is to be understood that minor changes in design or appearance of the parts may be resorted to without departing from the spirit of the invention or sacrificing any of its advantages.

As in the previous patent referred to above, I provide a davit arm or quadrant 10 adapted to roll outwardly for the purpose of delivering or launching a lifeboat over the side of the ship 11. In this instance each of said quadrants 10 includes a rocker having an arc-shaped base 12 with side flanges 13 cooperating with an inclined support or chair 1% constituting the lower portion of a bracket 15 secured in any suitable manner to the deck of the ship as by screws or lag bolts 1-6. The upper edge of the chair 14: is substantially straight throughout its main portion and the curved lower surface of the rocker coiiperates therewith during the movements of the quadrant. At each end of the track portion of the chair 14; and at the ends of the rocker I provide interlocking elements or features consisting of a lug or projection on one member adapted to enter and cohperate with a corresponding depression in the other. T he lug or toe 17 at the inner edge of the rocker is shown cooperating with a socket or depression 18 at the upper end of the incline 14:, and a corresponding toe 19 at the outer end of the rocker is adapted to roll into a socket 20 at the lower end of the incline. l would have it distinctly understood, however, that the reversal of these features, making the toes on the chair project upwardly into corresponding sockets at the ends of the rocker and even the reversal of the straight and curved'surfaces of the rocker and chair, would be an expedient fully within the spirit of the invention. The toe 17 coiiperating with the socket 18 prevents any possibility of lateral displacement of the davit arms or quadrants when in the elevated position, and likewise the toes 19 in the sockets 20 in the other extreme position constitute a positive interlock.

To prevent undesirable displacement or slippage between the rockers and the chairs when, both sets of toes are out of engagement with the sockets, I provide a strap 21 for each rocker, the same being pivoted on one end at 22 to the end of the rocker and at its other end ishinged at 23 to the chair. This strap is in the nature of a strong, flexible, flat metal band of sutficient strength to resist the lateral strains which may be occasioned in practice and which will not buckle because of any tendency which might occur in the, rockers to slide downwardly upon the chairs. As shown in dotted lines in Fig. 1, the upper end of the strap rolls upon the curved surface of the rocker 'to which it is connected when the davit arm rolls outwardly. This action upon the strap places it under tension and may, under certain circumstances, act as a retarding or cushioning device for the outward movements of the davit arms, and which tension will serve to tend to assist in restoring the davit arms to their normal elevated position in conjunction with the main hoisting and controlling cables. Said strap receives the direct impact or rolling friction between the rocker and the track member 14.

As the davit arms are brought to their upright position they strike against spring buffers 2d, the strength of which springs is stored while the arms are held in normal position, and when the arms are released the bufiers or starters 24iserve to initiate the outward rolling action of the davit arms even though the ship may be at aconsiderable list. These buffers are carried by or formed in the upper portion of the main rigid brackets 15. Any suitable cushioning de vice, indicated at 25, may be employed to re ceive the final impact of the rockers as they reach their downward limit of movement against the outer ends of the brackets 15.

At 26 I show a rock shaft journaled at its ends in the brackets 15 near the deck, and as indicated in Fig. 2 the space between the brackets otherwise is practically unobstructed, allowing free space for boats to be moved outwardly from emidships toward the side of the ship between the brackets; that is to say, when the two boats, which are normally carried adjacent the davits one above the other, have been delivered, any number of boats may be delivered from the same davits in succession by passing them be tween the standards or supports. Above each end of the rock shaft 26 is jo-urnaled a cam support 27 for the end of the uppermost lifeboat, each of said supports 27 including lugs 28 and 29 with a space between them corresponding to the keel 30 of the boat, but with such space so shaped as to provide for free rolling action between the keel and the support 27 as the boat comes into or out of place thereon.

A lever 31 is connected rigidly in any suitable manner to the rock shaft 26 andextends normally inwardly within reach of the operator. At the other end of the rock shaft similar lever 31 is provided lying in the same plane as the lever 31. To the axis of each of the cam supports 27 is secured a lever 82 which likewise in normal position extends substantially horizontally,

and each lever 31 is connected to the lever 32 above it by means of a rod or link 33. The point of connection, however, of the link 33 with the lever 31. is preferably considerably farther. from the rock shaft than is the length of the lever 32. With the parts in normal position and in which position the lifeboat B is supported above the axes 3d of the supports 27, if the operator lifts upwardly upon the lever 31 he will impart to the rock shaft 26 a certain rotation, and the links 33 pushing upwardly upon the levers 32 will give a greater rotation to the sup ports 27 in inverse proportion to the relative lengths of the levers 32 and 31. This movement of the supports 27 carries the keel 30 outwardly beyond the vertical plane of the axes 34 by contact therewith. of the preferably so proportioned that the cam supports are turned substantially through an angle of 90-degrees where they remain until the boat B is restored to its position thereon. When theboat is thus restored, the keel coming into place against-the outer edges of the lugs 29 will cause the supports to turn into or toward supportingposition, but which action may be completedby a downward thrust upon the lever 31 causing the rail 35 of the boat to be brought snugly into engagement with a pair of rigid arms or hooks 36 secured to the brackets 15 near their upper ends. So long,.therefore, as the supports 27 are in normal position, the boat B cannot become displaced in any direction.

The upper end or head of each of the quadrants is bifurcated and supports a sheave 37 upon a pivot 38. A pair of hooks or hangers 39 are pivotally mounted upon the pivot 38 onopposite sides of the head and extend-downwardly therefrom in normal position for supporting the shackle 40 connected to the end of the boat. The shackle includes a sheave 41 mounted upon a shaft 42 having at its outer ends a pair of antifriction rollers 43 bearing upon the hooks aforesaid. The outward swing of the hooks is limited by stop lugs or pins 44 extending outwardly from the sides of the head, and one or more springs 45 acting upon the hooks tend to force them againstor toward the pins 44. When the shackles are brought into engaging position with the hooks, the rollers 43 ride over the front inclined-surfaces 46 of the hooks, the springs allowing the hooks to swing rearwardly, if-necessary,

for this purpose.- Under normal conditions, therefore, the weight of the boat and its. load will be supported by the shackles and hooks rather than upon the cables 47, after the boat is delivered from the keel supports 27. When, however, the boat is swung far enough outwardly for it to .be controlled by the main cables, the shackleswill roll freely from the hooks. I

The upper ends of the cables 47 are secured at the points 48 in the heads and the cables extend thence around and under the sheaves 41; thence around and over the sheaves 37, and thence over guideipulleys 49 and 50 to a main drum 51 secured to a shaft 52 located at any convenient place preferably adjacent one of the brackets 15 and having-its axis arranged in any desired position with respect to the other parts of the mechanism. The two cables 47 are connectedto the same main drum and by leading therefrom in different directions, the strain upon the drum shaft 52 is to a large extent neutralized. The operation of the drum 51 is controlled by any suitable type of wheel 53 having any suitable reduction gearing 53' between it and the shaft. The wheel 53 may be operated by hand or otherwise and may constitute a portion of a brake having a shoe or strap 54 acting thereupon under the control of-a line 55 leading either into the boat or elsewhere, whereby an occupant 'of the boat may control the speed of descent in the event that all persons have left the ship. Obviously the brake may be controlled by the operator on the deck, if desired.

At 56 I show a pair of auxiliary or check ropes connected at their outer ends to the davit arms at 57 and extending thence rearwardly and downwardly over pulleys 58 to a check drum 59 mounted loosely upon the shaft 52 adjacent one end of the main drum 51. The primary purpose of the check drum upon the weather, the listing of the ship or other conditions. For instance, if it should be desirable to load the boat after it has left its'normal supports, the davit arms will be released and lowered ,by the action upon the main cables 47 to the point desired, the check ropes paying out freely from the auxiliary or check drum 59 for this purpose. The check drum, however, may bestopped and held at the desired point by any suitable means as, for instance, a brake member 60 secured rigidly to the drum and controlled by a brake band 61 through a lever 62. The

unwinding action of the cables 56 from the check drum 59, however, is resisted in a moderate] degree by the action of a spring 63 whose function primarily is to rewind the check ropes upon-the drum 59 when the davit arms are returned'to normal position by direct action of the cables 47. One end of the spring is shown connected to a collar 64 surrounding the shaft 52 and held in fixed position upon a support or arm 65 extending downwardly between the two drums. The other end of the spring obviously is connected to the drum at the point 661 In order tohoist the davit arms directly from the check ropes as is desirable at times when the boat is supported in lose bights of the main cables as, for instance, when it is desired to bring the boat close to the ship for loading or unloading purposes, and when a direct draft upon the main cables would not lift the davit arms, I provide a clutch comprise ing a member 67 secured to the check" drum or the brake element 60 thereof and with which cooperates a slidable clutch cone 68 splined upon the shaft 52 and controlled by a lever 69 or its equivalent.

The boat is shown supported in normal position between the brackets 15 and below the boat B. This lower boat may be supported upon chairs 70 through which the rock shafts 26 may extend and which may till constitute bearings for said shaft. This lower boat, furthermore, may be secured in position by any convenient means. A strut 7 2 is preferably used for normally supporting the middle portion of the upper boat B, said strut engaging the keel 30 and support ed in any suitable manner upon or within the bottom of the boat B.

While the rocker 12 with its parallel flanges 13 cooperates directly with the track portion 14 of each chair or bracket 15 to prevent the lateral displacement of the davit arm with respect to the chair, the upper portion of the rocker is maintained in substantially upright position by means of the spaced parallel side bars 73 of the bracket. The rear portion of each bracket is connected by means of a web 7 a and-the outer or front portion of the same includes a horizontal connecting bar 75.

The connection above referred to between the check cables 56 and the davit arms may be variably arranged, and as indicated in Fig. 1 the upper end of each cable coiiperates with a spring 76 which abuts against the keeper or bracket 57 while the extreme end of each cable 56 extends beyond the springs .76 and is connected to the hanger 39 by means of a clevis 77 or other suitable connection. When the davit arms are moved outwardly toward launching position, the apparatus being controlled primarily by the main cables 47, if the davit arms are to he stopped at any position intermediate the normal upri ht and extreme outward positions, in the checking of the check drum 59 by means of the brake strap 61, the first efiiect of the pull upon the check cables 56 will be to draw the hanger 39 upwardly against the spring 4'5 and insuring that the shackles 40 will be free to allow the boat to gravitate toward the sea. As before stated, however, the main support or point of connection between the cables 56 and the davit arms will be the keepers or brackets. 57.

The chair blocks above referred to are of the nature shown in Fig. 8. Each of them consists of a metal piece rigidly secured to the upper portion 73 of a bracket 15, and in or to which a cam support 27 is journaled on its axis 34;. Each of these blocks includes one or more fingers78 which project upwardly from the upper or inner portions and which serve as positive steps for the keel 30 of the boat as it comes into place on or in the cam supports 27. Adjacent the vertical fingers 78 the block is provided. with a substantially horizontal seat 7 9 upon which the keel 30 or" the boat rests in connection with the cam support 27.

The davit arms 10 shown in Fig. 9 are of the same general construction and operation as those shown in Fig. 1, but in some cases I make such arms of greater curvature whereby each of the arms extends well over toward the vertical plane of the axis of the boat B but with the body of the arm moved well inwardly toward the middle portion of the boat considered longitudinally or in such a manner that the two davit arms operating as a pair are much closer to each other than would be possible in the form shown in Fig. 1. F or example, with the davit arms curved in parallel vertical planes as indicated in Fig. 9, a boat of the size shown in Fig. 1 would permit the curved arms to be arranged so closely together as to receive the boat at almost its widest part. This provides for a more satisfactory and reliable support for the boat while being loaded in normal position as is sometimes demanded. This figure also illustrates the formation of the rocker 12 with one or more teeth or projections 12 intermediate the toes 17 and 19 which span or straddle the strap 21 and cooperate with shoulders formed by pockets 12* on opposite sides ot' the inclined chair 14. By this arrangement at least one of the toes of pro" jections is always in interlocking engagement with a chair, and hence, even though the strap 21 should break orprove defective, no serious accident can result by the slippage'of the davits uponthe chairs. The teeth or side members 12 like the flange members 13 of Figs. 1 and 5, span or straddie the strap and track portion 14 of the chair, preventing lateral displacement or slippage of the davit arm.

The hanger 39 for supporting the shackle 40, as shown in Fig. 9 of the drawings, is of the same general nature as the hanger 39 as above described, but by providing stop pins 14: and 44:"- adapted to be fixed in the head of the arm at any desired points, the hanger may be caused to project well outwardly beyond the vertical plane of the axis 38 of the pulley 37, thereby increasing the outward reach of the davit arms for the purpose before referred to. The shaft &2 of they pulley 4:1 coiiperates with the hook of the hanger as previously described and normally sustains the weight of the shackle 10 relieving such weight from the cable e7.

The checking construction shown in Fig. 9 is somewhat differest from that above described in that the check ropes 56 are connected at the points 80 directly to the inner ends of the rockers 12 near the toes 17. Each rope operates over a pulley 81 fixed in the bracket 15 and extends thence to a watertight casing 82 mounted conveniently in an upright position just inside oil the bracket, such end of the cable being connect ed to a plunger 83 between which and the upper end of the casing is interposed a resilient member in the form of a coil spring 84- which possesses several functions, among which is the initiating of the outward rolling action of the davit arm because of the normal strain upon the spring due to the seating of the toe 17 in the socket 18. In other words, when'the davit arms are to be rolled outwardly, the action of the spring or springs 84 serves to initiate such action even though the ship has a list. Such force of the spring continues until the davit arm reaches substantially its mid position and then for a moment is inefiective. When the davit arm approaches its outward limit'iof movement, however, the spring 8& is again put under compression to even a greater ex tent than it is normally, whereby the shock incident to the rolling of the davit arm outwardly against the fixed bracket stop is reduced. This arrangement of the auxiliary check mechanism simplifies the drum construction and means for manipulating the main cables 17. Furthermore, the resilient member 84 is protected from the salt air and water whereby the life and efficiency of the spring are materially enhanced.

I claim 1. In an automatic davit, the combination of a pair of vertically arranged rigid supporting brackets eachhaving near its base a track member and having sockets formed at the upper and lower ends thereof, a pair of davit arms supported upon said brackets and each including a rocker member cooperating with the track member of the supporting bracket of such arm, said cooperating rocker and track members having relatively curved and straight coacting surfaces, each rocker member furthermore having at its ends a pair of downwardly projecting, .toes adapted to cooperate at the ends of the with the, aforesaidrocking movements sockets, and a flexible flat metallic strap extending between said engaging surfaces and connected at its opposite ends to thefrocker and track members respectively, said flat strap receiving directly the impact and rolling friction between the rocker and the tread member.

2. In an automatic davit, the combination of a vertical rigid supporting bracket inclnding'a track memberadjacent its base, a rear connecting web, a pair of spaced parallel side bars extending forwardly from said rear web and connecting bar at the outer or front portion, a davit arm supported upon said bracket, said arm including a rocker adapted to roll along said track member and adapted to be limited in its outwardmovement by said connecting bar, and a resilient member connected to vsaid rear web acting normally upon the davit arm to initiate its outward rolling movement.

3. In an automatic davit, the combination of a pair of spaced parallel vertical supporting brackets, each bracket including atrack member at its-base, a vertical transverse rear portion and a pair of spaced parallel forwardly projecting bars, a pair of I davit arms,supported upon said brackets between the bars thereof, each davit arm including a rocker member adapted to roll upon the track member of the supporting bracket, resilient members acting between the upper portions of the brackets and the davit arms serving to initiate the outwardly rolling action of the davit arms, and means carried by the outer portions of the brackets and extending between the pairs of parallel bars thereof to limit the outward movement of the arms.

4. In an automatic davit, the combination of a pair of rigid supports, a pair of davit arms adapted to roll upon said supports, means to confine the arms as desired to proper rolling position upon the supports, each of the davit, arms having a bifurcated head, a sheave pivoted in the bifurcation upon a pivot pin extending through the sides of the head, a pair of hooks suspended from said pivot pin, a shackle including a sheave and a shaft for the sheave adapted tocooperate with said hooks, and a main controlling cable for each davit arm secured at one end to the head, extending thence under and around the shackle sheave and thence over and around the head sheave,

substantially as set forth.

5. In automatic davit construction, a movable davit arm having a bifurcated head at its upper end, a sheave in said bifurcation, a pivot pin extending through the head for supporting said sheave,-stop means extending laterally from the head, a pair of hooks suspended from said sheave pin, means tending to hold the hooks outwardly toward said stop means, a boat supporting shackle cooperating with said hooks and including a sheave having antifriction rollers for direct engagement with the hooks, and a flexible controlling member cooperating with said sheaves, substantially as set forth.

6. In an automatic. davit, the combination of a rigid stationary bracket including an inclined chair, said chair having a socket at each end and having a smooth unbroken surface between said sockets, a davit arm havin a rocker portion cooperating with said c air and having downwardly projecting toes at its ends interlocking in alternation with said chair sockets, and a flexible fiat strap secured at one end to the chair and at the other end to the opposite end of the rocker and adapted to lie upon said unbroken surface to receive directly the weight of the rocker, said rocker furthermore being provided between the toes with a pair of downwardly projecting members spanning the strap and cooperating with said chair to prevent lateral displacement of the'rocker. 7. In an automatic davit, the combination of a pair of davit arms movable in parallel vertical planes, boat supporting shackles supported normally upon said arms, a pair of main cables cooperating with said arms and shackles for supporting the boat after the shackles leave the arms, a drum to control the action of the main cables, a power shaft to which said drum is connected, an auxiliary drum journaled upon said power shaft, a stationary support adjacent the auxiliary drum, a spring having one end connected to said support and the other end to the auxiliary drum, and a pair of auxiliary cables extending from the auxiliary drum to the arms, said spring tending to maintain the auxiliary cables taut.

8. In an automatic davit, the combination of a pair of davit arms movable from upright position to swing outwardly for lowering a boat, boat supporting means carried by said arms, a pair of main cables cooperating with said arms and supporting means to control the usual movements of the boat, a main drum to control the action of the main cables, a power shaft journaled in horizontal bearings and to which the main drum is rigidly secured, .power means connected to the shaft to control its rotation and that of the main drum, a stationary support through which the central portion of the main shaft is journaled, an auxiliary drum journaled upon the shaft adjacent said last mentioned support, a pair of auxiliary cables connected to the auxiliary drum and extending thence to the arms, a spring connected at one end to said stationary support and at its other end to the auxiliary drum and tending to hold the auxiliary cables taut, and means to apply power from the shaft to the auxiliary drum to cause the auxiliary cables to elevate the arms independently of the main cables and drum. 7

9. In an automatic davit, the combination of a pair of cam supports, a pair of eoaxially arranged shafts to which the cam supports are connected, a rock shaft arranged parallelto the above mentioned. shafts, means to rotate the rock shaft, and connections between the rock shaft and the other shafts to cause rotation of the first mentioned shafts and supports when the rock shaft is rotated.

10. In an automatic davit, the combination of main supports, a pair of short shafts arranged eoaxially in the main supports, keel cam supports connected to said shafts, levers connected to said shafts, a rock shaft below the short shafts and parallel thereto levers connected to the rock shaft, and rigid links pivotally connected to the levers aforesaid whereby whenthe rock shaft is rotated,

the cam supports will be rotated to seat or unseat the boat keel.

11. In an automatic davit, the combination of a pair of main supports, a pair of short shafts journaled eoaxially of each other in said supports, a pair of keel supporting cams connected to said short shafts, each cam having a pair of projections extending upwardly on opposite sides of the keel supported thereby, a pair' of levers extending laterally from the shafts, a rock shaft parallel to and below both of said shafts, a pair of levers extending normally

Images