CRANE. 



815 



Crape. 



Mr Oil- 

 pin's crane, 

 Plate 

 CCXV. 

 fiff. 5. 



circle. Plate CCXV. eontains two of the best construc- 

 tions on this principle. Fig. 5. is one invented by Mi- 

 Gilbert Gilpin, who presented it to the Society of Arts. 

 It is particularly adapted for the use of a foundry, 

 where heavy articles are required to be Lifted in every 

 part of the circle that the crane describes. The whole 

 machine consists of a gib, the wheel-work being attached 

 to it. The perpendicular, AB, is formed of two oak 

 planks, only one of which can be seen in the Figure ; 

 they are eighteen inches wide, four thick, and sixteen 

 feet long. These, at the top and bottom, are let into 

 east-iron mortise pieces CD, which retain the planks 

 at ten inches asunder. E is the barrel for the chain, 

 which lias a spiral groove turned in its circumference, 

 for the reception of the links of the chain : it turns in 

 the space between the two uprights AB. The top mor- 

 tise piece C, as shewn by the dotted lines, has in the 

 middle a dovetailed mortise, into which the stock H 

 for the gib is fixed, and three bolts shewn at k secure 

 the planks H fast to the uprights. These planks are 

 of the same dimensions as the uprights, and the space 

 between them forms a groove or opening for the top 

 block K to slide in. The block is made of cast-iron, 

 and has two grooves, which slide upon the upper edge 

 of the planks H, only one of which is seen in the Fi- 

 gure. The block K carries the pulley m, over which 

 the chain passes. The diagonal stay M is formed in 

 a similar manner, and of the same dimensions as the 

 other parts of the gib : it is connected to the perpendi- 

 cular, by being received into the lower mortise piece 

 D. N is the handle or winch to work the crane ; it 

 has a small pinion O fixed on the same axis : this pi- 

 nion works in the teeth of the wheel P, on the same 

 axle as the chain barrel E. S is the running block and 

 hook, by which the goods are raised. Fig. 6. is an 

 edge view of the lower part of the perpendicular, shew- 

 ing the handle N, the pinion O, the great wheel P, 

 and the barrel E, placed betwixt the two uprights AB. 

 The whole of this crane is moveable on the pivots of 

 the gib, the lower one of which is supported on the 

 groundsil R, and the other by a beam F, extended 

 across the building in which it is placed, so that the gib 

 has liberty of traversing all round, to take up a burden 

 ■at any part. The block K also slides along the upper 

 beam H of the gib, and can be fixed at any place, 

 which admits of the block S being brought perpendi- 

 cularly over any spot. This is of very great import- 

 ance in an iron foundry, for lifting heavy castings, can- 

 non, &c. out of the moulds. We have Seen one of 

 these, in which the sliding block K had a long toothed 

 rack attached to it. This was worked by a pinion, the 

 axis of which carried a pulley for the reception of an 

 endless rope, hanging down in reach of the workmen, 

 Who could therefore, by means of it, turn the pinion, 

 and move the rack with the block to the desired spot, 

 so as to give the crane any range within its reach ; and 

 it would take up a weight as well at six feet from the 

 centre as at ten, which rendered it a most useful im- 

 plement in such a situation, where the crane is fre- 

 quently used to lower down moulds upon one another 

 in a perpendicular direction. Mr Gilpin's crane shews 

 a very good mode of construction for the gib, scarcely 

 any part of the timber being cut away, and the strength 

 of the materials, so far from being diminished, is aug- 

 mented by the cast-iron mortise pieces. The upper 

 beam of the gib is brought much closer to the upper 

 gudgeon, and the centre lines of the perpendicular and 

 • the diagonal stay crossing each other at the top of the 

 lower mortise piece, places the whole strain as near as 



possible in a line with the gudgeons, ^Ghe business of Craft*. 

 the perpendicular becomes in consequence little more ""T"""" - 

 than that of a mere prop, and consequently requires no 

 greater strength of materials than the diagonal stay. 

 The barrel E, for the chain, is, as before mentioned, Chain bav- 

 formed with a spiral groove, for the reception of the r *l- 

 lower halves of those links which stand upright, the 

 intermediate links lying flat on the surface of the bar- 

 rel, as is shewn on a cross section, Fig. 7. By this ^ LATE , 

 means the chain leads extremely fair, and will work with ' l „ ' 

 far less friction than ropes, or any other contrivance. Ife '" ' 

 The pulleys S and K are grooved in the same manner. 

 Fig. 8. by way of contrast, shews the awkward man- f'S- 8. 

 ner in which the links of a similar chain arrange them- 

 selves on a common pulley, tending to rend open the 

 links as much as to resist the strain. This method of 

 reeving chains, and substituting them for ropes, hasj 

 within these few years, become very general, as well 

 in cranes as in the engines for drawing coals out of 

 mines. It was, we believe, first adopted by the inge- 

 nious Mr Smeaton, in a crane he erected at the custom- 

 house, about thirty years ago. 



Fig. 9. represents a crane mounted on four trucks, to Mr Kier's 

 be capable of removal from place to place. It is em- moveable 

 ployed on Ramsgate pier, for lifting stones used in the crai!e - 

 building, and is extremely Avell adapted for such a situ- F '^' y " 

 ation, as it requires no fixture, and will take up a weight 

 of 4 tons with four men, without any danger of upset- 

 ting, which is a sufficient power for such purposes. It 

 was designed and executed by Mr Peter Kier, by order 

 of the trustees for the management of the harbour at 

 Ramsgate. Its base consists of a cast iron frame mark- 

 ed AB, 9 feet 7 inches square, and two tons weight, 

 supported on four cast iron wheels b, b, one pair of which 

 is fixed on a common axle, which moves round on a 

 centre fixed to one side of the frame. This axle has an 

 arm projecting across beneath the frame to the opposite 

 side, where a rack, or segment of a wheel, is fixed on it, 

 as shewn at c, engaging a pinion r, shewn before the 

 rack, on the top of whose axis a winch is applied at d. 

 Now by turning this pinion, it twists the wheels round 

 upon their centre, to steer the crane when moving from 

 place to place. A vertical cast iron shaft DF, weighing 

 23 cwt. is erected on the centre of the iron frame, and 

 is supported by oak braces E, E, stepped into boxes cast 

 out of the iron frame AB at its angles, so as to form a 

 very strong perpendicular column, round which axis 

 the whole crane traverses. The weight of the fra- 

 ming and wheelwork, is supported by a steel pivot or 

 gudgeon on the top of the shaft at F, and is guided by 

 a collar embracing the shaft at I. The framing of the 

 gib, or moveable part of the crane, consists of a long 

 beam GH, bearing the pulley G at the extremity, rest- 

 ing on the pivot of the upright pillar in the middle, and 

 the other end supporting the frame for the wheelwork 

 LMN. Intp this beam are framed two uprights Q, Q, 

 suspending the platform IK, on which the men avIio 

 work the crane stand. It is braced by a diagonal stay 

 IP, and a cross piece R to prevent its bending. 



MrBramah's ingenious hydrostatic principle of gain- BramaL's 

 ing a great power,is applicable in several ways to the rais- Uydrostaiic 

 ing of heavy weights, and has been frequently employ- crane - 

 ed in powerful cranes. In these, the power is not ob- 

 tained by wheelwork, pulleys, or any other of the ordi- 

 nary mechanical powers, but on the principle of the ex- 

 periment called the hydrostatic paradox, which has been 

 known for ages ; but the application of its powers to 

 useful purposes is due to Mr Bramah. 



The simplest form is, for a machine to raise a heavy 



