US 2374240 A
Description (OCR text may contain errors)
pri 241, 1945. M, SHANKMAN 2,374,240
Filed Oct. 30, 1942 5 Sheets-Sheet 2 FiEI EI l 3mm MaI-tin .Enhankman pi 24, w45. M. SHANKMAN 2,374,240
TANK v Filed oct. 3o, 1942 3 sheets-sheet 5 Martin Shan-1km an @www hemd Apr. :mp4s:
Martin snankman, nunungio, N. Y.
, Application october so, 1942, sei-lama. 463,819
(Granted under :ne et of March s, lass, u
amended April so, 192s: 31o o. o. 151i The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.
'Ihis invention relates to amphibious tanks, such as would be used by assault troops attempting to establish a bea-ch head.
When assault troops try to establish a beach' head, they approach the enemy-held beach in force from surface vessels which come in as close as practicable to the beach. There they disembark in landing boats of some kind and make for shore. Such boats should aiord the troops protection against light machine gun and rie fire, and should permit them to move in fast.
It is the object; of this invention to provide an amphibian tank capable of launching from a troop carrier for the approach to an enemy-held beach. The tank is preferably propelled through the water by its track, which can be lengthened for the purpose. The tank carries a turretmounted machine gun.
The tank is designed to carry a driver and a gunner, and is well adapted for use in squads of twelve to a squad. Weight of a tank would not exceed three tons, and would preferably be held closer to two tons.
The specific nature of the invention as Well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:
Fig. 1 of the drawings is an elevational view of a tank of the invention with its tracks positioned for land travel.
Fig. 2 is a view similar to Fig. 1 showing the tank with its tracks positioned for water travel.
Fig. 3 is a view in perspective of the mechanism to lower and raise the track.
Fig. 4 is a side elevational view of the tank interior, the shell being in section to show the arrangement inside the tank.
Fig. 5 is a top view of the tank.
Fig. 6 is a top View, with the shell in section to show the interior.
Fig. 7 is a detail view of the hydraulic power' system used to raise and lower the tank with respect to a portion of the track.
Referring to the drawings in detail, especially to Figs. 1 and 2, a body or hull 2 is shown provided wlth a turret 4 at its forward end through which a machine gun 6 projects. The tank is carried and propelled by an endless track 8 which runs on a drive sprocket I0, lower idler wheels l2, end wheel I4, and upper idler wheels or rollers I6.
As can better bev seen in Fig. 3, lower idler wheels l2 are carried on trucks I8. Each of trucks I8 is mounted on a piston rod 2B, on which is mounted a piston 22 which moves in a double acting cylinder '24. Cylinders 2| are mounted in a projecting compartment 25 on the side of the tank. End wheels i4 are moved up and down by the piston, not shown, of cylinder 26 through bell crank 21. Cylinder 26 may be single or double acting. If single acting, the power will be applied to move the wheels downward to take up the slack when lengthening the track for water travel.
Fig. l`i shows the tank interior. As can be seen in this figure and Figs. 5 and 6. the tank body consists of a substantially spherical forward portion 28 made, preferably, of about half-inch armor plate and welded to a generally rectangular portion 30 which is also armor plate but of a thinner section, such as quarter inch material. The portion 28 is provided with vision slits 32. Surmounting the spherical portion and forming ra part of it is the turret 4, in which gun 6 is mounted by means of a ball and socket joint indicated generally by 34. A slit 36 in the forward part of the turret provides visio-n for the gunner. The turret may if desired be made of a thinner section than the rest of the spherical portion.
The rectangular portion 3B of the body has a trap door 38 to permit entering and leaving the tank. A ventilator unit fill is also provided in the upper surface. Any suitable power plant 42 is mounted in the rear part of the tank. A heat exchanger M, such as a radiator for an internal combustion engine, may be disposed behind a substantially bullet-proof grille 46. The exhaust` pipe 68 can be passed through a small openingA in the upper surface of the body. Fuel for engine 42 may be carried in tanks 52. The connections between fuel tanks and engine are not shown, nor are throttle controls and the like, inasmuch as these are conventional and form' in themselves no part of this invention.
A drive shaft 54 transmits power to a controlled differential 56 through a power take-off SBand a shaft B0. Steering may be by means of the controlled differential or by means of track clutches and brakes, not shown, although the controlled differential will be recognized as preferred. Either method is conventional and need not be detailed here.
A drivers seat B2 is shown at the left of the shaft 60, and a gunners seat `(il is shown as wheels I2 and I4. This nuid may be supplied by a pump 68 connected to be driven by motor 42 through shaft d and power take-off B. The pump may of course be a conventional pump adapted to the type of iluid used in the system, which may be pneumatic or hydraulic, by way of example. A pneumatic system has the advantage ot providing cushioning means in addition to the springing action in trucks i8, and a hydraulic system has the advantage of more positive response.
Various conduits connect the pump 66 to cylinders 24 and 2 8 through a valve 12. The details orthis'system are best shown in Fig. 7. A conduit 14 connects the pump discharge with the middle of the valve cylinder, in which is mounted a slide 16 to cover and uncover ports 'I8 and 60. Port 'I8 leads to the upper side of pistons 22 in cylinders 24, to the lower side of the pistons in cylinders 26, by means of` conduits 82, 84, and86 as shown. Port 80 leads to the lower face of the pistons in cylinders 24 and to the upper'iace of the pistons in cylinders 26 through conduits 88, 00, 82, and 94. The ends of the valve cylinder are connected to the pump suction through conduit 96 and a reservoir 88. A handle |00 permits the manipulation of slide 16.
Operation- If the tank is in condition for land travel, and it is desired to prepare it for water travel, handle |00 is pushed inward toward the valve body. Slide 16 thereupon uncovers ports 16 and 60, exposing the lower sides of pistons 22 and the upper faces of the pistons in cylinders 26 to the high pressure side, or discharge, of pumpv 6l through port 60. The upper ends of cylinders 24 and the lower ends of cylinders 26 are connected to the suction, or low-pressure, side of the pump through port 76. Cylinders 24 raise the idler wheels I2, and cylinders 26 lower the end wheels I4, lengthening the lower portion of the track to the condition shown in Fig; 2. The track will then propel the tank through the water.
If then it is desired to prepare the tank again for land travel, handle |00 is pulled outward from the valve cylinder, uncovering ports 18 and 80 and zonnecting, through port 18, the upper ends of :ylinders 24 and the lower ends of cylinders 26 with the pump discharge; the lower ends of cylinlers 24 and the upper ends of cylinders 26 are hereby connected to the-pump discharge through ort 60. The lower portion of the track is therey lowered with relation to the tank, putting the ank in the condition shown in Fig. 1.
1. In a track-laying vehicle, a drive motor, racks driven b y said motor, idlers in engagement vith the inside of the tracks and operable to raise r lower the vehicle body'with relation to the racks, idlers normally above and ahead of the ither idlers, and means for lowering the last-inenioned idlers to bring them substantially in line with the other idlers when the vehicle body` is )wered relative to the tracks to take up slack in he tracks and incidentally lengthen its traction ase.
2. In a track-laying vehicle, a drive :notons sprocket driven by said motor, a rockably mounted idler spaced from the sprocket and substantially in line therewith, a track around the sprocket and said idler, other idlers in engagement with the inside of the track between the sprocket and the rockable idler, means for raising the intermediate idlers to diminish the distance between the track 'and thefbottom of the vehicle body and incidentally cause slack in the track, and means for rocking the rockable idler to take up the slack and incidentally lengthen the traction base oi' the track.
3. In an amphibious track-laying vehicle having a substantially water-tight hull, a sprocket at one end of the hull, a drive motor within the hull for driving the sprocket, an idler at the opposite end of the hull and forming an idler'oi the track, idler wheels between and substantially in line withv the sprocket and end idler, means for raising the intermediate idlers with respect to the hull and simultaneously depressing the end idler into engagement with the track to elongate its traction base to condition the vehicle for water travel.
4. An amphibious track-laying vehicle, comprising a drive motor, tracks driven by said motor, a substantially rectangular water-tight hull having a laterally projecting compartment on each side, a cylinder in each end of each compartment, double acting pistons in said cylinder, idlers connected with said pistons below the compartments and constituting suspension means for supporting the vehicle. on the tracks, fluid pressure means for reciprocating the pistons in said cylinders to raise and lower the suspension means relative to the vehicle body, and idlers in line with the idlers of the suspension means, a cylinder for each of the last-mentioned idlers, each of said cylinders having a piston connected with said idlers and arranged vto move them from one slack take-up position to another, and fluid pressure connections between the idlercylinders and the suspension means cylinders, whereby when the idlers oi.' the suspension means are raised, the other idlers will be depressed to elongate 4the traction base of the tracks to condition the vehicle for water travel.
5. In an amphibious track-laying vehicle, having a substantially water-tight hull, an elongatable track, a motor driven sprocket outside the hull and at one end thereof, and an idler at the other in line with thesprocket, reciprocable vehicle suspension means between the sprocket and the idler and adapted when extended to support the hull on said track above the ground, means for reciprocating the suspension means to raise or lower the hull with respect to the track and depress the idler when the hull is lowered to elongate the track and incidentally lengthen the traction base thereof and condition the vehicle for water travel.
6. In a track-laying vehicle, a drive motor for .the vehicle, a fluid pressure pump driven by the