Patent GB-148596-A (GB)
Title: Improvements in, and relating to, structures adapted for use as propellers for shipsand other crafts, and also for pumping and other purposes
IPC: B63H1/08
Filed: 1919-03-20
Abstract: 148,596. Icre, J. B. March 20, 1919. Propelling.-Relates to a feathering device for rotary propellers of the type in which the blades are turned into their operative positions by a stationary cam once in every revolution, and is described in connexion with marine vessels. A hollow shaft 20, Fig. 7<a>, extends vertically through the hull and is supported by a bearing composed of a ring 22<b> on the shaft running on an outer ring 23<a> secured to the hull, while another ring 22<a> on the shaft runs on a stationary ring 23<a>, bearing-balls being interposed in each case. The upper end of the shaft 20 carries a ring 24<a> which runs on an outer supporting-ring 24<b>. The shaft carries a bevel wheel 25 meshing with another wheel 25<a> on a shaft 25b which is operated from the driving-shaft of the engine by gearing 25<c>. A cap 26 prevents access of water to the working parts. Radial hubs 27 are provided on the shaft 20 to support the shanks of the feathering blades 27<a>. A vertical shaft 28, normally stationary, is arranged within the shaft 20 and is supported in a bearing 28a. The shaft 28 carries a cam-track, which is shown enlarged in Fig. 10, and consists of two separate sleeve sections 29 attached by keys 29<a>. Each sleeve is provided with a flange forming a cam track having horizontal and inclined portions, and each flange is provided with face-plates 43 attached by shanks 43<a> to provide for renewal when worn. The cam track has a relatively long horizontal upper portion, a short horizontal lower portion, and two oppositely inclined connecting portions. Guide-blocks 30, Fig. 9, operate between the flanges, and are carried by cranks 30<b> secured to the inner ends of the .shanks of the blades 27<a>. When the main shaft 20 is rotated, the blocks 30 travel between the flanges and turn the blades 27a into the required operative or inoperative positions. The angular position of the shaft 28 may be varied by gearing such as 28<d> so that the cam track is varied in position, and consequently the phase of the feathering is varied. Reversal of the vessel may be obtained in this way. When the propeller is employed on aerial vessels, a raising or lowering effect may be produced. When two propellers are employed, they are preferably rotated in opposite directions, and their cam tracks are set so that their propulsive action is the same. A pair of propellers may be arranged amidships, or one pair near the stern and another pair near the bow, for the purpose of swinging the vessel in situ. The propeller and track shown in Figs. 19 to 22 are suitable for vertical steering. Instead of being rigid with the shaft 28, the track is composed of two relatively movable sections. The horizontal portion m, Fig. 9, is formed on a sleeve segment 29<c>, Figs. 19 and 20, which is movable lengthwise between the spaced edges of a wider segment 29<d> which carries the horizontal portion n. Rings 29<f> rigidly secured to one segment and sliding on the other segment compel the two segments to remain in contact. Each intermediate portion o is made of two sliding members 29<g> with pin and slot connexions. Each of the sleeve segments 29<c>, 29<d> is formed with horizontal circumferential grooves in engagement with pinions 44, 44<1>, which are normally held against rotation by spring-pressed pawls 53, but which may be rotated to alter the setting of the cam tracks when required. The track portions m, n, o may thus be brought into the same horizontal plane, when the blades are kept in an inclined position and a lifting or lowering effect is produced. Other combinations of the track portions are also described. The cranks 30<b>, Fig. 9, are so arranged that they are always in tension. The arrangement of the cam-track shown ensures that, when the blade is being feathered, its upper edge is inclined in the direction of rotation so that the blade exerts a downward pressure on the water and tends to lift the vessel. A modification of the construction shown in Fig. 7<a> is described, in which the central shaft 28 extends downwards into an horizontal tunnel and carries at its lower end the bevel gears necessary for its adjustment. Fig. 17 slows a vessel fitted with a propeller of the above type in combination with a screw propeller 45<b>. The shaft 45a is connected by a detachable coupling 45<c> with the driving-shaft 45 which operates the shafts 25b, 20 through a belt 46<b>. A well 47 is provided, into which the propeller 27a can be raised for repairs, when the outlet can be closed by a slide 49 operated by a rack and pinion 49<1>, 50. Fig. 8 shows the arrangement when the propeller is arranged amidships, the construction being similar to those previously described. The main shaft 32 is surrounded by packing-rings 35, 35a held by plates 36 on horizontal slide plates 37 located above and below the recess 38. The main shaft with its propeller and attached parts may be moved bodily inwards by sliding the plates 37 by means of the screwed rods 39 operated by the gearing 39<c>. The opening of the recess 38 may then be closed by a vertical gate 40 and the water pumped out, when repairs may be effected. The propellers may be arranged on horizontal axes similar to paddle wheels as shown in Figs. 31 and 32. The propellers A<2> are arranged amidships, and the cam-setting device may be operated through a tunnel T'. The propellers may be withdrawn into a recess which may be closed by a sliding gate.