US1555404A - Apparatus for launching ships' lifeboats - Google Patents

Description

sept. 2 9, 1925. A1,555,404

J; CROSSLEY' vAPPARATUS FOR LAUNCHING SHIPS LIFEBOATS sept. 29, 1925. 1,555,404 1 l y .1. cRossLEv APPARATUS FOR LAUNCHNG SHIPS LIFEBQATS Fued 'may 12. 1525 5 sheets-sheet 2 sem. 29,1925

J. GROSSI-.EY

APPARATUS FOR LAUNCHING SHIPS* LIFEBQATS 5 sheets-sheet s Filed May 12. 1925' sept. 29, 1925. 1,555,404

gJ. cRossLEY APPARATUS LAUNGHING SHIPS LIFEBOATS 'Fflled May 12. 1923 5 sheets-sheet 4 INVENTOK Sept. 29, 1925.

I J. CROSSLEY 5 APPARATUS FOR LAUNCHING SHIPS' LIFEBOATS Filed May 12, 1925 5 Sheets-Sheet 5 Patented Sept. 29, 11925.

UNTED STATES' TENT OFFICE.

JOSEPH CROSSLEY, F BALMAIN, NEAR SYDNEY, NEW SOUTH WALES, AUSTRALIA.

APPARATUS FOR LAUNCHING SHIPS LIFEBOATS.

Application filed May 12, 1923.

To @ZZ tofu/)m t may conce/"a:

Be it known that I, Jessen CROSSLEY. subject of the ling of Great Britain and Ireland, residing at rlhe Adelaide Steamship Company Limited, Balmain, near Sydney, in the county of Cumberland and State of New South TWales, Australia, have invented certain new and useful Improvements in Apparatus for Launching Ships Lifeboats, of which the following is a specification.

rlhis invention relates to boat launching` and boat stowing apparatus of the type in which boats are suspended from davits which are capable of a tilting movement outboard for the purpose of swinging boats clear of ships sides for launching and raising operations.

According to this invention the boat launching apparatus is characterized in that the da fits are formed with feet which are each terminally fitted with heel trunuious and toe trunnions which are so disposed that the centre of gravity of the davits and the boats weight hung on them is outside the vertical above the heel trunnions so that the davits always tend to swing outboard. The tee trunnions and the heel trunnions respectively engage and rest in pillow blocks fixed on the ships deck when the davits are swung outboard and swung inboard respectively. @ther constructional features and arrangements are hereinafter set forth.

In the accompanying drawing.

F ig. l is an elevational View showing a ships boat seated on bilge checks and a kell bearer with the gripes fastened and the davits swung inboard, as the parts appear when viewed from the ships deck looking outward;

F 2 is a fragmentary sectional perspective showing the keel bearer in which the boat rests with the keel latches and their actuating gear and a collapsing guard rail for enclosing Jthe deck space below the boat;

Fig. 3 is an end elevational View showing a boat stowed in its checks with two gripes fixed and the gear fully inboard;

Fig. l is a transverse section on the line we Fig. 'l with the boat shown in elevation;

F ig. 5 is an end elevational view explanatory of the operation of launching, showing the davits partly swung out, the boat clear of the keel bearer and the bilge checks, and the gripes released;

serial No. 638,472.

Fig. 6 is a fragmentary elevational View explanatory of the retiring movements of the keel bearer and bilge chocks in the operation of launching a boat; y

F 7 is an end elevational view showing the davits fully extended and the boat fully swung out over a Fships side with clearance to allow for backward heel of the ship to an angle of more or less;

Fig. 8 is a fragmentary elevational View illustrative of a winch and braking mechanism thereon for controlling the boat lifting falls-alternative to ordinary manual tackle;

Fig. 9 is a lay-out plan indicative of the arrangement for operating the tackle at either end of the boat from the winch (Fig. l0) which is located atrone end of the boats position on the deck; and

Fig. l0 is a fragmentary sectional elevation of the gearing in the winch by means of which a worm drive operated by a hand crank may be engaged or disengaged and the boat fall rope drums controlled by a band brake with screw adjustment.

The structure is built almost wholly of standard rolled sections. Cost is thus minimized and lightness ensured.

The swinging davits are formed of I beams outwardly bent at the top ends as shown at 2l and carrying at their top ends shackle suspensions 22 for the head blocks 23 of the boat tackle 24, 25 being the foot blocks of this tackle. Each fall 26 of the boat tackle is carried through a fair lead block 27 hung on the davit to bitts 28 ou the front pillar 29 of the stanchion frame structure 30, each davit 2O having a stanchion frame appropriately fastened down to the ships deck. The davit head is hung back to the top end of the frame 30 by the independent wire tackles running over the stanchions 3l and 32; one fall of this tackle 33 being brought under the swinging fair lead block 34 to one of the winch barrels 35, the other winch barrel 36 being allocated to the corresponding fall line 37 leading from the other davit of the pair. The davit tackle is quite independent of the boat falls. The winch which controls the swinging movement of the davits consists of two barrels 3:5-36 on which the falls 33 and. B7 are respectively wound, a coupling spur gear wheel 39 engages spurs on the barrels $5-- 36, a transfer spur wheel 40 keyed to the same axle ll as a worm wheel 4t2, and a worm 43 intergearing with the worm wheel 42. The shaft 44 which carries the worm 43 carries also a spur pinion 45. This pinion is in mesh with a large spur gear wheel 46 having a hand crank 47 on either or both ends of the shaft 43 which carries it. The worm shaft 44 may also be fitted with a hand crank.

ln lifting the boat 49 inboard a hand crank fitted on the worm shaft 44 is operated to drive theJ winch through the worm 43 and worm wheel 42, a heavy purchase being thus obtained with complementary slow movement. For lowering away rapidly, however, thewinch is controlled by means of the crank or cranks 47 which operate the spur wheel 46; the worm 43 is low pitched so that it is not reversely rotated by the worm wheel 42 under the load applied through the tails 33 and 37; the worm, is tl erefore, self-locking and the winch cannot run away if during the llifting operation the hand crank 47 is freed. By means of the hand cranks 47, however, the worm may be readily induced to rotate rapidly under the assistance of the load applied to it through the falls 33 and 37 and the intern mediate gearing, and a safe and rapid lowering action can be performed with Ithe same security against the running away of the winch in the event of the hand crank 47 being liberated. In the lifting movement, the spur wheel 46 operates idly and the energy required to turn it is almost negligible so that the friction in the winch mechanism is not augmented because of the provision of the selfelocking and rapid releasing feature which has been described.

The foot end of each of the davits 20 is fitted with a heel piece 50 formed of plates reinforced at the edges with angle sections. The heel carries at its extremity a heel trunnion pin 5l; this trunnion sets in a pillow block 52 which is fixed to the ships deck; it is housed between two panel plates 54 forming part of the structure of the stanchien trame 30 to which the davit is hung back, and it is movable through arc slots 53 in those plates. At its forward side each davit 2O is formed with a toe piece 55 which termia es also in a toe trunnion pin 56 which, like the trunnion pin 5l, sets in a pillow block 57 .fixed to a base on the ships deck. In the inboard position of the davit, the tow trunnion 56 lifts and the whole of the davit load is carried on the heel trunnion 5l (see 3). In the intermediate position, when the boat is swung quite clear of the checks, the davit rests on the two trunnions 5l and 56 (see Fig. 5) g in the full outboard position the whole of the davit load is carried on the toe trunnion 56, and the heel trunnion 5l rises to the top end of the guide slot 53 and checks itself against the top end of that slot so assisting to support the davit in conjunction with its hanging falls 33. 58 is a guide face against which the toe trunnion 56 runs in rising from and descending into the pillow block 57.

Brackets 60 on the forward side of the davit near the foot form a support for the keel bearer 6l. rlfhis bearer is an angle frame extending the full length of the boat; as seen in Figs. l and 2 it is reinforced and stitfened with an angle bar 62, on the flange portion of which several latches 63 are pivotally mounted as shown at 64. The lower ends of these latches 63 are connected by rod .linkage 65 to a hand pull and push bar 66 which is accessible at one end of the structure. rlhis bar 66 is' provided with a readily detachable locking device (not shown). By throwing the bar 66 in one direction, the latches 63 are set upstanding to lock the keel of the boat on the keel bearer 61 and hold the boat secure in the inboard position. An opposite movement applied to the bar 66 throws the latches 63 clear to allow the boat to be swung laterally outward off the Vbearer 6l. 63 are bolster blocks fixed to the davits 26. lenti-ally of the boats length two bilge checks 7() are provided. These bilge checks are carried on a rocking table comprising a platform member 7l which is pivotally connected at its outer side 72 to the keel bearer structure 6L and at its inner side at 73 to a pivotal swinging strut 74. The strut 74 is fitted with a heavy pawl 75 which is engageable with a quadrant detent 76, said detent being cut to allow the pawl 75 to run outwardly over it but to check inward movement. It is consequently necessary to lift the pawl 75 to free the structure for inboard movement, but it may be swung outboard with the pawl in engagement with the sector detent. The function of the pawl and quadrant detent is to prevent accidental inboard swinging of the davits during the launching operation, as might happen in the event of the ship lurching excessively so far as to throw the balance backward whilst the davit is only partially outswung. Owing to the angular' disposition of the pivotal strut 74, the bilge checks are lifted in the inboard movement so that. they are brought up to bed tightly under the inner bilge of the boat when, the boat is fully swung inboard with its keel in the keel bearer 6l, and to disengage automatically on davit arms being lowered.

The double trunnion footing for the davits obviates entirely the great inconveniences associated with all forms of davit construction in which the foot of the davit is constructed as a sector rolling in a channel or on a rail under control of a toothed segment and rack or under control of rope lashings to maintain the davit-s position. lt is well recognized that such channels and rails are very liable to obstruction causing interfering independently of the lowering tackle 33. This preventer stay 1s a chain lashing 80 with a turnbuckle tightener 81, and a slip hook 82, the hook being secured by a. clasp ring 83. Preparatory to launching z operations, the hook 82 must be freed; this is readily accomplished by knocking back the ring 83.

ln the stowed position the boats are held snug by inboard and outboard gripe chains 85 and 86 respectively. These chains embrace the boats gunwale by means of loose claws 87; each gripe is fitted with a slip hook 88 secured by a slip ring 89 and it also includes a rope lashing 90, or union screws may be fitted. The inner gripes 85 are hung in the deck hooks 91, the mouths of which hooks face outboard. Similarly the lower ends of the outboard gripes 86 are hung in downwardly projecting hooks 92 fixed on the shell of the ship. It is not necessary to release the gripes before commencing the lowering operation. lli/Then lowering commences, the movement being outboard and downward, the gripes slacken and finally pull clear of the hooks 91-92; the boat is consequently held by the gripes quite firmly until lowering operations commence. It is, therefore, practicable to load the boat with passengers whilst it is carried on the bilge checks and keel bearer and to swing it outboard and lower it in loaded condition without the necessity of using force to move it off chocks and clear away. All the inconvenience, delay and danger accompanying the placing of passengers in the boat whilst it is hanging outswung on davits is thus entirely avoided and a great measure of safety is obtained.

To facilitate the loading of the boat a companion way 94 is provided midway of the boats length and leading up to the level of the boats gunwale (see Fig. 4), this companion way being fitted with a hand rail 95 and serving incidentally to cover the davit winch.

A clear deck may be left below the keel bearer structure 62 but in the case of passenger ships where it is desirable to provide a guard nail for the deck, such rail consists of pendent chains 97 carrying rail bars 98. The chains 97 are suspended from the keel bearer structure 62 (see Fig. 2) and the lower ends of the chains 97 are lashed at 99 or otherwise secured by shackles to eye bolts 100 on the deck. This rail collapses in the launching' operation and automatically 1estores itself in the stowing operation. ln order to preserve maximum deck promenade space, the keel bearers may be set seven feet or higher above the deck level, the davit winch erected on a fixed stage or platform, and the pawl and sector (-76) fitting and the companion steps 94 omitted.

The boat falls, which so far have been described only as manual falls held in the bitts 28 are preferably mechanically controlled by means of an auxiliary winch (see Figs. 8, 9, 10), in which case single wire falls or a double part wire fall would be used. This winch consists of two barrels, 101-102 respectively on the ends of a shaft 103 which extends along the deck from one davit to the other. The winch 104 which controls the shaft 103 and through it the two fall barrels 101-102 is located at one end of the assembly. The shaft 103 carries a spur wheel 105 and a brake drum 106. A band brake 107 coacts with the drum 106; it is controlled by a screw 108 which is fitted with a hand wheel 109 at the top end of it. This hand wheel may be located at the outboard side of the structure so that it may be conveniently handled by a seaman whilst looking over the ships side at the descending boat. The spur gear 105 intergears with a spur 110 on a lay shaft 111 on which also is keyed a worm wheel; a worm 112 meshes with this worm wheel when the shaft 113 on which the worm is fixed is tilted downward. This shaft is mounted in a tilting bearing 114 at one end and in a lift bearing 115 controlled by a 4hand screw 116 at the other end, and it is fitted with hand cranks 117. By moving down the shaft 113 by means of the hand screw 116 to engage its worm 112 with the worm wheel, winding motion may be applied to lift the boat by means of the hand cranks 117. For quick lowering movement, the shaft 113 is tilted upward as shown in Fig. 10 to clear the worm from the worm wheel, and then the lowering away is controlled entirely by the brake band 107 under control of the hand wheel 109.

It is to be noted that in Fig. 8 the brake control hand wheel 109 is shown on the inner side of the winch; as already described it is preferable that it should be located at the outboard side of it. 120 are foot step bars xed on one side of the stanchions 29 for the convenience of seamen to enable them to reach the sheaves and tackle overhead and offer access to the boat as seen in Fig. 4.

The davits, owing to the heel and toe support trunnion arrangement, always tend to swing outboard. In the inboard position the centre of support is at the heel-trunnion 51 consequently when the tackle is eased away, and the keel latches are released the weight of the boat operates at once to assist the swing outboard. `When the outboard movement has been partially completed the toe trunnion 56 takes the load, and the heel trunnion 5l operates as a preventer chock to prevent falling of the davits in the event of the top tackle carrying away. From the full outboard position shown in Fig. l, when the boat is well clear from the ships side, the lowering operation can be performed either by slipping the boat falls through the bitts 28, or by lowering them away by means of the winch 101i. The alter native worm gear with the release arrangement which is provided for the davit head tackle, and for the boat fall tackle offer the greatest facility to raising as well as lowering the boats, permitting` the lowering movement to be accomplished with great rapidity and the raising `movement to be accomplished with minimum manual effort; furthermore the arrangement of the platform carrying the bilfge chocks in association with the keel bearerI carried by 'the brackets in the lower end of the davits ensures a rapid and quick stowing and releasing of the boats, whilst the check pawl 75 coacting with the quadrant detent T6 ensures in the launching operation security against inswinging of the suspension in the event of the vessel rolling heavily.

By setting the heel trunnions and the toe trunnionsA further apart the stability of the davits to resist any tendency to sag back in the event of the ship rolling excessively is augmented and their reach increased.

I claim:

l. In boat launching apparatus of the type in which the outswinging davits are hung back to fixed stanchions and are formed with feet which are fitted with heel trunnions and toe trunnions, said trunnions resting in pillow blocks on the ships deck, quadrant slot check guides for the davit heel trunnions, said guides formed in panel plates which form part of the stanchion structure.

2. In boat launching apparatus of the outswinging davit type, a boat keel bearer supported on brackets Xed on the outer faces of the davits7 a guard rail consisting of pendent chains and longitudinal bars, said chains suspended from the keel bearer structure and fixed along the deck line so that in the inswung position of the davits and the consequent lifted position of the keel bearer the chains will be drawn taut and the rails held extended thereby.

3. In combination with boat launching apparatus according to claim 1 a boat keel bearer supported on brackets fixed on the outer faces of the davits, a bilge chock platform pivotally connected at its outer edge with said keel bearer and at its inner edge supported on pivotal legs which are angularly disposed to tilt the platform upward in the inswinging movement of the davits and downward in the outswinging movement of the davts.

il. In boat launching apparatus of the gravity outswinging davit type, a winch to swing the davits inboard and outboard by means of tackles, said winch characterized in that the winding of the falls is effected through a crank driven low angle worm gear and that the paying out of the falls is controlled by a crank driven spur wheel which is high geared to the worm spindle.

In testimony whereof I affix my signature.

JOSEPH CROSSLEY.

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