US2599444A - Apparatus for raising and transporting loads - Google Patents

Description

June 3, 1952 R. c. GAVIN APPARATUS FOR RAISING AND TRANSPORTING LOADS 4 Sheets-Sheet 1 Filed Jan. 7, 1947 June 3, 1952 R. c. GAVIN APPARATUS FOR RAISING AND TRANSPORTING LOADS 4 Sheets-Sheet 2 Filed Jan. 7, 1947 A wIZ/ EK June 3, 1952 R. c. GAVIN APPARATUS FOR RAISING AND TRANSPORTING LOADS 4 Sheets-Sheet 5 Filed Jan. 7, 1947 J1me 1952 R. c. GAVIN 2,599,444

APPARATUS FOR RAISING AND TRANSPORTING LOADS Filed Jan. 7, 1947 4 Sheets-Sheet'4 F/GS 222-4 1 20 I 23 y 33 "mul 4111 I l I I l 1 I I l l l I l l l l l I l I l l l l l l l l lll llllll lllllll ll|llH|||ll|ll|lH| l Z I: '5

Patented June 3, 1952 UNITED ETATES PATENT QFFECE APPARATUS FOR RAISING AND TRANSPORTING LOADS Application January '7, 1947, Serial No. 720,609 In Great Britain January 17, 1946 (C1. UMP-175) 2 Claims.

This invention relates to traversing skip hoists of the type described in the specification of British Patent No. 331,955, in which a skip is lifted either vertically or at an angle until it attains a certain height and then is traversed substantially horizonally to one of a number of selected dischar e points.

In designing skip hoists of this type various mechanical factors place a limit on the maximum convenient size of skip and there are other factors which, in practice, limit the speed at which the hoist may conveniently be operated. Together, these factors constitute a practical limit to the capacity of a single skip hoist, and, where capacities in excess of this are required it is usual to increase the number of hoists.

To decrease the expense of so doing as well as to reduce the power consumption required per ton of material handled twin tracks and skips are provided and lengths of haulage and retracting ropes are associated with each skip, said haulage ropes being wound up alternately by a winch driven by a motor and the retracting ropes serving to draw back along the horizontal part of the track, the discharged skips. The ropes may either be wound on the winch drum or drums in opposite directions so that when one skip moves in one direction the other can move in the reverse direction or the same result may be secured by arranging that two winch drums shall rotate in opposite directions.

When using two skips to obtain a certain lifting capacity it is obviously desirable to utilize the weight of the descending skip as part-counterbalance to the ascending filled skip. However, as in the type of hoist referred to the travel of each skip is partly vertical and partly horizontal, it is evident that the skip which is travelling horizontally cannot counterbalance the skip which is travelling vertically and it is arranged that one skip is ascending the vertical travel while the other is descending, the former reaching the point of transition to substantially horizontal travel at the same time as the latter reaches the bottom position. In order that the skip which has been hoisted may continue from the top of the rising portion of its travel towards the desired point of discharge without causing slacking-01f of the haulage rope attached to the other skip which is resting at the bottom, a tension weight is provided in a bight of each haulage length of rope between the winch drum and its skip. This arrangement not only ensures that the weight of the descending empty skip is available as part counterweight to that of the ascending filled skip, but also enables either skip to be traversed horizontally to any one of a number of selected discharge points without regard to the point at which the other skip is being dis-.- charged. If desired one skip may be utilized to fill one bunker and the other to fill another.

In order that the invention may be more read; ily understood it will now be further described with the aid of the accompanying drawings in which Fig. 1 is a skeleton diagram typifying the arrangement shown conventionally in three dif'! ferent conditions in Figs. 2, 3 and 4. Fig. 5 is a side view of one skip (b) and its associated care.

riage, and Figs. 6 and 7 are sectional views taken respectively along lines VI and VII of Fig. 5.

Referring first to Fig. 1, a and 12 represent two tension weight and a pulley carriage. Considere.

ing the skip b, one rope, the haulage rope l is ate tached to the skip and after passing around thepulley 2 on the two-pulley carriage 4%, Fig. '7, is di-..

rooted to the winch which comprises two drums 4 arranged one behind the other so that only one drum appears in the figure. The rope l in:- cludes abight supporting the tension weight 5.

The other rope 6 is attached to the counterweight l and is directed by other pulleys 8, 9 to the pulley carriage 3 or else to a pulley on the pulley carriage, after passing over which pulley it is attached to the skip. The ropes l and 6 are connected to a bridle 25, Figs. 5, 6 and 7, pivoted on the skip, small guide rollers 2| at the free end of the bridle moving in the channels of the track rails. Buffers 23 are provided on the carriage against which the skip bridle 20 abuts when the skip reaches the upper part of the vertical portion of the track. The tension weights 5 and 5 of the two skips are limited as to up.- ward movement by suitable stops l0. panion rope and pulley system for skip a is denoted by the numerals I 3 5 6 l instead of 3 5 6 and l Here it will be understood that the ropes l and l are wound on the drums 4 in opposite directions which accounts for the bight in both ropes appearing in Fig. l.

The function of each counterweight is to return the associated skip and pulley carriage from the point at which the skip is stopped and discharged, back to the point at which the pulley carriage is left behind against a stop and the skip continues its travel downwards. Stops to prevent the carriages following the skip down the substantially vertical portions of the tracks The com 3 are indicated at x in Figs. 5 and 7, these stops as being fixed at the top of each track-channel rail so as to leave the space between the rails clear for passage of the skip but to lie in the path of the laterally projecting angle irons y fixed to the carriage. It is not necessary for the counterweight to be in motion when the skip is descending or ascending, though it may in practice he more convenient for it to be so.

In Fig. 1, three discharge ramps H are indicated, two being retired and the one at position X advanced to effect discharge there. Briefly what occurs is:

As skip a advances to dischage position X counterweight 1 is drawn upwards, tension weight 5 being maintained against stop H! by the superior pull of counterweight 1 At the same time the tension weight 5 descends from stop It! and preserves tension in the haulage rope l to skip b but without lifting it as the skip b is heavier than the tension weight 5* (see also Fig. 3). During this period skip b begins to be filled. When skip a reaches position X and is discharged the winch 4 reverses and skip a is drawn back as counterweight l descends. At the same time tension weight 5 rises until it meets stop II] when skip b commences to ascend.

Considering now Figs. 2, 3 and 4, Fig. 2 indicates that the skip a has just passed the top of its vertical ascent, the other skip b having reached the lowest point of its travel. While skip a is travelling horizontally towards its discharge position and the hauling rope l for skip b is in consequence still being payed out from the winch drum 4, tension is maintained in the hauling rope l of skip b by the associated tension weight 5 which during this part of the operation is lowered away from the stop It] it being understood that the weight '5 rests against its stop during those parts of the travel of skip b which involve its lifting or haulage movement. The actual distance of movement of the tension weight away from the stop depends entirely upon the horizontal traversing movement of the skip a and vice versa. Fig. 3 is indicative of the position of the parts when skip a is at discharge position. When the skip a has again reached, on its return trip, the point at which it is about to descend and at which skip b is about to be hauled upwards, it is arranged that the tension weight 5 reaches its stop 10 and further winding of the skip b haulage rope I on to the winch drum 4 results in movement of the skip b. Fig. 4 depicts the skips a and b midway of their vertical travel skip b ascending.

What I claim is:

1. A traversing skip hoist comprising twin pairs of tracks, each pair having a substantially vertical portion and a substantially horizontal portion and a carriage running on each horizontal portion of the track adapted to guide the haulage rope of the related skip while said skip is traversing the vertical portion of the track; a skip on each pair of tracks; a reversible winch at the outer ends of the horizontal portions; a haulage rope from each skip to said winch, the ropes being wound on the winch in opposite directions and being of such length that the skips travel the vertical track portions simultaneously in opposite directions, and that the downwardly-bound skip rests at the bottom of its vertical track portion during the entire horizontal run of the other skip; weighted means on each haulage rope to take up the slack due to unwinding after the downwardly-bound skip bottoms at the end of its downward travel; each weighted means comprising a bight in each haulage rope between its associated skip and said winch; a tension weight suspended in said bight; and a stationary stop adapted to limit upward movement of the tension weight while the related skip is traversing the vertical portion of its track; and retracting means yieldably urging the return of each skip to its vertical track portion from the horizontal track portion, each retracting means comprising pulley guides between the tracks of each pair near the junction of the vertical and horizontal portions thereof; a rope through each set of guides attached at one end to its associated skip; and a counterweight attached to the other end of each rope opposing the pull of the winch so that the pull of the counterweight yieldably urges the skip toward the junction of the hori zontal and vertical portions, thereby serving to return the skip toward the junction while on the horizontal portion and also serving as a counterweight when the said skip is on the vertical portion of its track.

2. In a skip hoist as set forth in claim 1, stops to prevent the carriage from passing from the horizontal portions to the vertical portions of the tracks; said guides comprising pulleys on said carriages; and each haulage rope and each retractin rope passing around said pulleys to the winch and the counterweight respectively.

ROBERT CHALMERS GAVIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 473,846 Lucas Apr. 26, 1892 500,936 Northway et al July 4, 1893 985,398 Cook Feb. 28, 1911 991,217 Lewis May 2, 1911 1,331,780 Newhouse Feb. 24, 1920 1,333,948 Travell Mar. 16, 1920 2,291,387 Hale July 28, 1942

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