US3378153A - Double skip lifting and transporting device - Google Patents

Description

April 16, 1968 0. DOMENIGHETTI 3,373,153

DOUBLE SKIP LIFTING AND TRANSPORTING DEVICE Filed Feb. 14, 1966 2 sheds-sheet 1 INVENTOR Domen'mo bomb Lghefii S aLn-Qw and 3 mm ATTORNEYS April 16, 1968 o. DOMENIGHETTI ,378,

DOUBLE SKIP LIFTING AND TRANSPORTINC' DEVICE Filed Feb. 14, 1966 2 Sheets-Sheet z INVENTOR Doman'mo Donal- E, gke

ATTORNEYS United States Patent 3,378,153 DOUBLE SKIP LIF'IING AND TRANSPORTING DEVICE Domenico Domenighetti, 6 Via Nosetto, Bellinzona, Switzerland Filed Feb. 14, 1966, Ser. No. 527,282 Claims. (Cl. 214-103) ABSTRACT OF THE DISCLOSURE DOuble skip lifting and transporting device in which there are coupled to a single winch two skips which slide up and down on the same rail means and there is provided at the middle of the path a double switch system allowing for the two skips to keep moving in different directions without colliding.

In conventional building and road installations as well as in operative works for quarries, mines, cement factories etc., the equipment for conveying and lifting incoherent materials usually comprise means which have a rope attached to a skip unit sliding on variously inclined rail members. The skip generally begins its movement from a starting station in which it is charged with material e.g. crushed stone, in this position the winch rope being completely unwound. Actuation of the winch causes the rope to wind up on the drum, whereby its length is reduced and the skip is pulled up to a certain end position in which the material is discharged usually by turning over the skip or opening a discharge port of same.

The operation of such an installation generally consists in the continuous repetition of the following steps:

starting of the skip from its charge position transfer of the skip up to its end station stopping of the skip in said end station and discharge transfer back of the skip to its original starting position stopping of the skip in its original starting position and charge.

At the end of this last named operation the device is obviously ready to start the first operation over again.

Thus, such a device is adapted to perform an operative cycle which may be defined by its time of duration as well as by their number, should a succession of cycles be required for carrying out a given work.

In more recent installations the actuation of the winch motor is controlled by automatic electro devices which are excited by the so-called endstroke means that indicate when the skip has reached its end positions. In these modern installations also the charge and discharge phases are controlled by automatic timing means which, after a predetermined time has passed, set the winch going again to have the device perform the successive operation. They may be also controlled by outer excitation impulses from external operations which are somehow related to the operative cycle of the installation to be driven.

For instance should the skip be charged by a feeder unit, it will be this same feeder that indicates when the charge operation has been completed and that gives the impulse to the winch to have the skip started.

Independently from the driving and/or actuating system for the winch, it will he obviously of the greatest importance that each operative cycle is as short as possible to allow for the largest possible number of cycles per time and consequently for the transport of the largest quantity of material.

From a consideration of the various operations forming a cycle it clearly appears that, since the charge and discharge times for the skips cannot be reduced (as they ice depend from the nature of the material to be transported as well as from other operative factors that are independent from the lifting and transporting device) the only feature which may be improved is the displacement speed of the skip on the rails i.e. the winding time of the rope on the winch drum.

In the modern installations used for building and road construction works as well as in quarries, mines, cement factories and the like this speed is comprised between 2 and 2.7 ft./sec. (0.6 and 0.8 m./sec.) and may reach the value of 3.3 ft./sec. (1 m./sec.) only under very special and favourable conditions.

For avoiding too expensive embodiments (for instance variable speed winches) one is compelled to take into consideration certain inertia problems at the starting and other considerable difficulties at the turning over of the skip, if the transfer speed should overcome the above mentioned average values.

In the conventional installations for any given transport distance the duration of the cycle Was therefore set and could at the most be slightly reduced by increasing the transfer speed of the skip, which however could eventually bring about many dangers such as a wear of the ropes, vibrations, instabilities and so on.

Up to now the only solution to the problem of increasing the output was to provide for two or more identical installations to work side by side or to increase the capacity of the skip (and therefore the winch power). This last solution was however very expensive and not always desirable because it implied an increase of the overall dimensions.

It is the purpose of the present invention to drastically reduce the duration time of the cycle (less than half of the conventional time) while the length, and/or the heigth of the displacement path, the capacity of the skip, the charge and discharge stations and the relative operations thereof and first of all the transfer speed of the skip are kept unvaried. This speed remains in fact below the critical values so as to ensure an easy and long life opera tion of the whole installation.

These important results as well as other advantages are achieved according to the present invention by coupling to a single winch, two skips sliding up and down on the same rail means and by providing at the middle of the path for a double switch system allowing for the two skips to keep on moving in different. directions without colliding.

Conventional devices of this type (funicular railways etc.) usually have switch systems extending in horizontal and subhorizontal planes. However this kind of switch arrangements may not be easily utilized in the building road or mine works or installations we are concerned with.

The double switch device of the present invention extends, on the contrary in a vertical plane what brings about considerable simplifications.

A particular non-limitative embodiment of said device will now be described in detail by referring to the accompanying drawings, in which:

FIG. 1 is a diagrammatic elevation. of a conventional" device.

FIG. 2 is a diagrammatic elevation of a double skip device provided with the switch system according to the present invention.

FIG. 3 is a perspective view of a kind of skip used according to the present invention.

FIG. 4 is a perspective view of an improved skip type according to the present invention.

FIG. 5 and 5' diagrammatically show a method of utilization of the two switch pairs according to the invention.

FIG. 6 is a diagrammatic view of a mechanical actuaion mechanism for the switch system made to work by he very same weight of the skip.

The conventional lifting and transporting device as .hown in FIG. 1 consists of the rail means 1 made of two J-shaped profile pieces having a skip 2 moving thereon )y means of a pair of wheels 3 slidingly received within raid U-shaped profile pieces while a pair of wheels 4 are tupported by the upper wing portion thereof. The winch irum 5 has the towing rope 6 winding thereon and transnitted over the sheave or pulley 7 to be connected with he skip 2 over the auxiliary sheaves 8 and 9. While the ope 6 winds up on the drum 5, the skip 2 is made to nount up the end station 10 which, in the case, also coresponds to the discharge station. In face, due to a par- :icular conformation of the rails before reaching said :nd station the skip is made to turn upside down thereby iischarging the contained material from its upper out- )ut 11.

An embodiment of the device of the invention is illus- :rated in FIG. 2 wherein two skips are provided. The ;kip 2 is at the starting station, the skip 12 at the end and discharge station 10. The tow rope 6 is continuously driven to wind up on the drum 5. A branch 6 is deviated aver the transmission sheave 7 to reach the skip 2 while :he other branch portion 13, which is also deviated over :he sheave 7, is connected with the skip 12 over the pulieys 14 and 15. As a consequence of the station of the drum 5 in one direction the ropes pull on the skip 2 to have it move from the starting station to the end station 10 and contemporaneously act upon the skip 12 to have it move from the end station 10 to the starting station. Opposite rotation of the drum 5 causes opposite displacements of the skips. Since both the skips move on the same rails 1 they would collide at the middle of their path, should no special means be provided to avoid it, this :ollision is prevented by provision of a rail switch system according to the invention which consists in a branching off the rails to form two separate branch positions 16 and 17. The branch 16 always has the skip 2 and the branch 17 always has the skip 12 sliding thereon.

According to the invention there are two switches 18 and 19 each comprising a plurality of blades mechanically interconnected and actuated by a cam projecting from one of the two skips. These skips assume on the branches 16 and 17 respectively the positions 20 and 21, i.e. they move one over the other in a vertical plane without ever colliding. In fact, the central space between the rails is free and the side support wheels of the skips are guided by the switches to follow each its own path.

In FIG. 3, a skip comprising a tub unit or hopper 22 is mounted on axles 23 and 24 the ends of which are adapted torespectively receive the back wheels 4 and the front Wheels 3. These last named wheels slide within the U- shaped profile pieces forming the rails while the wheels 4 slide on the upper wing portion of said profile pieces. To transmit the pulling force of the rope 6, which in the case of FIG. 3 works with a double pull action there is provided a sheave 25 mounted on a draw stirrup 26, the arms of which are pivotedly mounted in the skip supports, while possible oscillations of said stirrup are controlled by two rollers 27 resting on the rails 1.

In the embodiment of FIG. 4, the skip with its hopper 22 is also mounted on axles 23 and 24, the ends of which are adapted to respectively receive the wheels 4 and 3. In this case, however the rope 6 which also exerts a double pulling action, engages the hopper 22 over a pair of sheaves 9 with substantially horizontal rotation axis as well as over pair of sheaves S with substantially vertical axis. Each sheave 9 is almost tangential to the adjacent sheave 8 so that the rope may easily pass underneath the hopper 22 to reach then the fixed end 28 of the towing rope 6. A switch system is shown in FIG. 5 with four blades 29, 30, 31 and 32 respectively pivoted in 29, 30, 31' and 32. This switch corresponds to the position in which the rail 1 branches oif to form the two portions 16 and 17. When the blades are in the position shown in FIG. 5 the skip passes from the rail 1 to the branch 17 since the wheels 3 are well as the wheels 4 are free to slide in such a direction. The two closely fittting blades 30 and 32, the free ends of which rest on the respective pivots 32' and 30 prevent the wheel 4 on its way up or down from stressing or damaging the switch, even though every wheel usually exerts a considerable stress with component normal to its rolling plane. Similar considerations may be made with regard to the wheels 3. In this case however the normal stresses may be easily removed by the blades 29, 31 and 32, the free ends of which rest on fixed point.

By simultaneously rotating all blades of an angle equal to the one existing between the branch portions 1 6 and 17, one comes to the position shown in FIG. 5' in which the skip is made to slide first on the rail 1 and then on the branch 16 or vice versa. In fact, the position of the blades leads the wheels 3 and 4 to follow the dashed paths 33 and 34.

FIG. 6 shows the back portion only of a mechanical control mechanism for the switch system of FIGS. 5 and 5. The pivots 29, 36, 31 and 32' re fixed to just as many control levers 29", 3G", 31 and 32" which are in their turn connected to linking rods 35, 36 and 37. The linking rod 37 extends to form a mobile rail 38 which is actuated for instance by pressure of a cam 39 coaxially mounted with respect to the wheels 4. By contacting the rail 38, the cam 39 imparts thereto a motion having a component 40 a direction transverse to the rail 1. This transverse component causes the contemporaneous rotation of 'all the levers 29", 30", 31 and 32" of a same angle and therefor a correspondent displacement of all the blades, which hence move from the position of FIG. 5' to the one of FIG. 5. When the cam 39 releases the rail 38, a return spring 41 will bring the switch back to the position of FIG. 5.

What is claimed is:

1. A main trackway having its lower and upper ends horizontally and vertically spaced from each other, a secondary trackway substantially shorter than the main trackway and having entrance and exit ends communicating with the main trackway intermediate the ends of the latter, switch means at the said exit and entrance ends, a pair of skips, power drive means interconnecting the skips for equal and opposite movements relative to each other such that when one skip is ascending the other skip is descending whereby one skip bypasses the other skip by the secondary trackway, means to cause tilting and dumping of the skips at the upper end of the main trackway, a skip loading station at the lower end of the main trackway, and means on one of the skips to engage and operate the switch means.

2. The device as claimed in claim 1, and in which each of said skips is provided with two pairs of sheaves respectively rotating on axes which are substantially perpendic ular to each other and with their peripheries arranged to be tangential to each other two by two so that the rope passing on said two sheave pairs may freely slide in a direction perpendicular to the sheave axis, whereby allowance is made for said skip to swing as required about an horizontal axis especially during the turning upside down of said skip in the discharge phase of same.

3. The device as claimed in claim 1, and in which each of said skips is provided with a drawing stirrup pivotally 5% closely fitting to each other so that the free end of one blade rests substantially on the pivot of the other blade, whereby the transverse stresses due to the skip Wheel are effectively resisted upon independently of the direction they come from.

5. The device as claimed in claim 4, and wherein the rotation pivots of said four blades are each provided with levers of equal length and parallel to each other, said levers being connected at their ends with linking rods, at least one of Which extends forming a mobile rail portion controllable by a cam mounted on one of said skips.

6 References Cited UNITED STATES PATENTS 730,799 6/1903 Rust 214-41 5 260,324 6/1882 Rockwell 214-1l 334,076 1/1886 Kitto et a1 214-1( GERALD M. FORLENZA, Primary Examiner.

10 R. B. JOHNSON, Assistant Examiner.

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