US960701A - Elevating machinery. - Google Patents

Description

A. T. PRESCOTT.

ELEVATING MACHINERY. APPLICATION FILED SEPT. 14,1909.

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. A. T. PRESCOTT. ELEVA'IING MAUHINERY.

APPLICATION FILED SEPL'H, 1909.

. Patented Ju'ne 7, 1910. 1

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ELEVATING MAGHINERY.

APPLIUATIOK FILED SEPT. 14,1909.

960,701 Patented June 7, 1910.

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'A. T. PRESCOTT. ELEVATING MACHINERY. APPLIGATION FILED SEPTL14, 1909.

Patented June 7, 1910.

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ARTHUR T. PRESCOTT, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T0 GEORGE E. FROTHINGI-IAM CO., A CORPORATION OF NEW YORK.

ELEVATING MACHINERY.

To all whom it may concern:

Be it known that I, ARTHUR T. Pnnscorr, a citizen of the United States of America, and a resident of East Orange, county of Essex, and State of New Jersey, have invented certain new and useful Improvements in Elevating Machinery, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof.

My invention relates to elevating machincry, and particularly to means for operating transfer bridges of ferry landings and the like.

It is common in this class of transfer bridge operating mechanism to employ counterweights to carry nearly all of the dead load, and to provide elevating screws which will carry the live load and the remainder of the dead load. Where these bridges are used in connect-ion with ferryboats it is common to have the bridge at an elevation slightly above the deck of the boat when the boat arrives and to immediately lower it so that certain parts carried by the bridge rest upon the boat. This relieves the elevating screws of all, or nearly all, of their load for the time being, and allows the bridge to move up and down with the boat as it rises and falls with the tide, or as the boat is loaded and unloaded. The bridge is usually pivoted or hinged at its shore end, and the water end in rising and falling therefore travels in the arc of a circle, and consequently the hanger beam which is near the water end, moves in such an are that the points of suspension will not remain in the axial lines of the screws. There is also a slight side to side movement caused by the movement of the boat and permitted by the looseness of the side guides of the bridge, and likewise a limited longitudinal movement caused by the longitudinal pressure of the vessel as it engages the bridge end. These movements are not great, but they are suflicient to cause the elevating screws to cramp unless provision is made to prevent it. In my present invention I provide guides for causing the screws to travel positively in right lines, and flexible connections between the lower ends of the screws and the bridge to' permit the relative movements of the bridge aforementioned. This arrangement permits not only free swinging movements of the bridge in every direction, but permits Specification of Letters Patent.

Application filed September 14, 1909.

Patented June 7, 1910.

Serial No. 517,575.

the screws to be lowered so as to allow the bridge to be supported by the boat, free of the suspension means.

My invention further consists in providing counterbalancing means for the screws and parts directly carried thereby, independent of the counterbalancing means of the bridge, so that the weight of the screws is taken off the nuts, and the pressure of the nuts upon their bearings is loosened. These counterbalancing weights are preferably sufficient to overbalance the screws,that is to say, they are preferably heavier than the screws and the directly connected parts, so that the screws are actually lifted thereby when the flexible connections between the screws and the bridge are slack. This divides the wear between the upper and lower surfaces of the screw and nut threads and also assists in the lubrication of the parts by providing channels for receiving the lubricant.

My invention further consists in an improved construction and arrangement of parts providing for the complete lubrication of the connecting parts, and particularly of the nut bearings.

My invention also consists in an improved form and construction of the housings or casings for the nuts, worm wheels, and worms for imparting movements thereto, permitting the ready removal of the worm from the worm wheel without the necessity of dismantling the whole structure, particularly where a worm and wheel of the Hindley type is employed, as is desirable.

My invention further consists in the employment of means for limiting the movements of the screws in opposite directions, such means conveniently comprising electric switches for cutting out the raising and lowering circuits of the motor employed for imparting movements to the worm and wheel mechanism in operating the elevating screws.

My invention further consists in many novel details of construction and combinations of parts, such as will be fully explained hereinafter.

In order that my invention may be clearly understood, I will now proceed to describe an embodiment thereof, having reference to the accompanying drawings illustrating the same, and will then point out the novel features in claims.

In the drawings: Figure 1 is a view in front elevation of transfer bridge operating machinery constructed in accordance with my invention, showing the same applied to the swinging gangways or bridges of a double-decked ferry house. Fig. 2 is a view .in central longitudinal section through the ferryhouse and operating machinery, showing a portion of a ferryboat as contained in the slip and having its decks in line with the transfer bridges. Fig. 3 is a top view of the operating mechanism. Fig. 1 is a view in central longitudinal section through one of the elevating screw operating devices. Fig. 5 is a top view of the parts shown in Fig. 4 with the elevating screw in transverse horizontal section. Fig. 6 is a view in side elevation of the part shown in Fig. 4. Fig. 7 is a transverse sectional view upon the line 7-7 of Fig. 41, showing the guide for the elevating screw.

The ferry landing illustrated is provided with two bridges or gangways, a lower main bridge 10 and an upper gangway 11. The bridge 10 is pivotally supported at its rear end 12 to a stationary part 13 of the main floor of the building, while the gangway 11 is pivoted at its rear end at 14: to an overhead structure 15 constituting an upper floor of the building. The elevating mechanism for the lower bridge comprises vertical non rotatable screws 16 mounted in rotatable nuts 17 supported by a gallows frame 18, the lower end of each of the screws being connected to the forward end of the bridge 10 by means of a rod or wire rope 19 and a section of chain 20. The lower ends of the screws 16 are guided in longitudinal stationary guides 21 by means of slides 22 carried by the said screws, the guides 21 being secured to the side walls of the ferryhouse or other building by means of frames 23 (see Figs. 1 and 7). The screws 16 are raised and lowered by the rotation of the nuts 17, and the slides 22 and guides 21 in sure the vertical movement of the said screws in right lines. The flexible connection, however, between the lower ends of the screws and the forward end of the bridge, comprising the links 19 and chains 20, permit the longitudinal, transverse, and swing-- ing movements of the bridge above referred to. Moreover, the chain elements 20, which are allowed to become slack when the bridge is supported by the boat, as by its beams 25 resting upon the deck of the boat, permit the free rising and falling of the bridge with the boat.

The nuts 17 are provided each with a' worm wheel 26, preferably removably secured thereto, so that either the nut or the worm wheel may be removed and renewed without it being necessary to renew the other part, the teeth of the worm wheels being engaged by worms 27 upon a main operating shaft 28, the latter being driven by suitable means, as by an electric motor 29. The worm 27, worm wheel 26, and nut 17 of each elevated screw are housed within an inclosing casing preferably formed in two parts,- a lower portion 30 and an upper portion 31, the two parts being secured together by bolts and nuts 32 which engage flanged portions thereof. The upper end of the upper portion 31 of the casing is provided with a cuplike flange 33 which constitutes a basin for containing lubricating material for the screw, and the upper end of the nut 17 is preferably provided with a steady bearing 31 in the upper part of the portion 31 be neath this oil reservoir; at its lower end the nut 17 rests upon a wearing plate 35, being preferably received within a shouldered recess therein. The lower portion 30 of the housing is provided with a dependent flange 36 and with a sleeve 37 therein, the upper portion of which extends above the level of the bearing plate 35 and is received within a suitably recessed portion of the nut 17. The lower part 30 of the casing may be kept flooded with oil whereby the lower bearing of the nut 17 will be kept thoroughly lubricated. The level of this oil, however, is preferably kept below the level of the top of the sleeve 36, whereby the oil is prevented from escaping down around the teeth of the screw 16, as is so common in screw elevating devices.

The lower portion of the worm 27 may enter the oil with advantage so that it will pick up oil and thoroughly lubricate the points of contact between the worm and the. worm wheel. The foregoing construction not only forms a complete housing for the operating parts, such as will thoroughly protect them against injury from external sources, but also forms, as will be readily understood, a highly efficient lubricating means for the parts without any waste of the lubricating material being permitted. A cover plate 58 may be provided for permitting ready access to the interior of the casing, for inspection, cleaning, and oiling purposes.

It will be noted that the two parts 30 and 31 are not divided upon a single horizontal plane, but, on the contrary, such division is made upon two planes connected diagonally through the bearing of the shaft 28. This is for the purpose of permitting the lateral movement of the shaft 28 and worm 27, after the upper part of the casing is removed and while the screw and parts carried thereby are retained in place. This permits a worm gearing of the Hindley type to be employed such as can only be separated by relative lateral movements, while at the same time it avoids the dividing of the casing throughout on a vertical line through the hearing such as would cause the casing to be leaky and incapable of retaining the oil.

It is common in transfer bridges to provide means for counterbalancing the dead Weight of the bridge, and for this purpose I have shown heavy counterbalancing weights 38 which are connected to the bridge by means of ropes 39. The ropes 39 pass over direction pulleys 40 carried by the gallows frame 18 and under floating pulleys 41 carried by the bridge 10; the ends of the ropes are anchored to the gallows frame 18 as is shown at 42 in Fig. 2. These weights are usually suflicient to carry almost all of the dead load of the bridge, the live load being carried by the elevating mechanism. The screws 16 and parts directly carried thereby are, however, themselves of considerable weight, running all the way from seven hundred to two thousand pounds, and as this is a dead weight which cannot be counterbalanced by the weights 38, or supported by the bridge, I have provided a special counterbalancing means therefor comprising weights 43 for each screw, connected thereto by wire ropes 44 which pass over stationary direction pulleys 45. The weights 43 are preferably heavy enough to more than counterbalance the screws, so that they will tend to press the upper portion of the threads thereof against the lower portion of the threads of the nuts, and will also tend to lift the nuts off their lower bearing surfaces. As the screws normally carry the remainder of the dead weightof the bridge not carried by the counterbalancing weights 38 and also carry the live load upon the bridge, these counterbalancing weights will ordinarily be overborne, so that the normal condition of the screws is with the lower portions of the threads in engagement with the upper portion of the threads of the nuts, and with the lower portion of the nuts pressing upon their hearing plates, but when the above mentioned practice is employed of permitting the bridge to rest upon the boat so that the boat carries the balance of the dead weight of the bridge and the live load thereon, and the screws are lowered to permit freedom of movement, then, for the time being, the screws will be lifted by their counterbalancing weights 43 in the manner aforesaid, and during the time they are being freely raised and lowered the wear will be taken off the surfaces which normally take the load and are subjected to the greatest wear, thus saving wear upon these surfaces, and further, by reason of the fact that there is always more or less play, thereby affording channels for the flow of lubricating material so as to assist in the lubrication of the parts. This latter is quite a valuable feature when it is realized how difficult it is to sueceed in causing oil or grease to flow between surfaces which'are in firm contact.

In order to show a complete operating means for double-decked landings, I have shown a connection with the main shaft 28 for operating the upper gangways 11, but it will be understood that the same forms no part of my present invention, but is disclosed and claimed in a copending application filed January 14, 1910, and serially numbered 520,075. This means includes a transverse shaft 46 driven by a worm and wheel connection 47 with the main shaft 28, and one or more secondary shafts 4849 driven by means of worm and worm wheel connections 50 and 51 from the said shaft 46. The shafts 4849 are provided with drums 5253 for receiving chains 5454, the lower ends of which are connected to the gangway The shaft 46 and the shafts 4849 are journaled in suitable bearings in the gallows frame 18.

In order to prevent accidental overthrow movements of the elevating screws 16, I have provided cut-out switches 5556 which are arranged to be operated by a plate 57 carried by the screw 16. Should the screw be raised too high the plate 57 will engage the switch 55 and cut out the circuit of the electric motor 29 by which movements to raise the screw are accomplished, while should the screw descend too far the plate 57 will engage the switch 56 to cutout the lowering circuit, whereby further movements in a downward direction will be inhibited.

While I have specially designed the elevating machinery for use in connection with transfer bridges, and have shown and described it herein as applied to transfer bridges of ferry houses, it will be understood that this is but one application of my invention and that the elevating mechanism is adapted to a wide range of uses.

What I claim is:

1. In mechanism of the class described, the combination with an elevating screw, means for moving the screw longitudinally, and a guide for limiting such movements to right line movements, of a swinging connecting element for connecting the elevating screw with the object to be raised, whereby the point of connection with the object may move laterally with respect to the longitudinal movements of the screw.

2. In mechanism of the class described, the combination with a swinging bridge, elevating screws therefor, and means for oper ating the elevating screws, of guides for limiting the movements of the screws to right line movements, and swinging connections bet-ween the bridge and the elevating screws.

3. In mechanism of the class described, the combination with an elevating screw, means for moving the screw longitudinally, and a guide for limiting such movements to right line movements, of a flexible swinging connecting element for connecting the elevating screw with the object to be raised.

4. In mechanism of the class described,

the combination with an elevating screw, means for moving the screw longitudinally, and a guide for limiting such movements to right line movements, of a flexible swinging connecting element for connecting the elevating screw with the object to be raised, the said flexible element including a section of chain.

5. In mechanism of the class described, the combination with a swinging bridge, elevating screws therefor, and means for operating the elevating screws, of a guide for limiting such movements to right line movements, and a flexible connection for connecting the bridge with the screws.

6. In mechanism of the class described, the combination with a swinging bridge, elevating screws therefor, and means for operating the elevating screws, of a guide for limiting such movements to right line movements, and a flexible chain connection for connecting the bridge with the screws.

7. In mechanism of the class described, the combination with an elevating screw, and means for suspending a load therefrom, of a counterbalancing weight therefor, in opposition to the weight of the screw and the load.

8. In mechanism of the class described, the combination with an elevating screw, and means for suspending a load therefrom, of a counterbalancing weight therefor sufficiently heavy to overbalance the screw and its positively connected parts, in opposition to the weight of the screw and the load.

9. In mechanism of the class described, the combination with an elevating screw, a nut thereon, and a lower bearing for the nut, of a counterbalancing weight for the screw and nut sufficiently heavy to lift the screw, nut and positively connected parts, when the weight of the object to be lifted is not supported by the said screw.

10. In mechanism of the class described, the combination with a swinging bridge, an elevating screw therefor, and a flexible connection between the elevating screw and the bridge, whereby the weight of the bridge may be independently borne and the elevating screw feed therefrom, of a counterbalancing weight for the screw of suflicient weight to lift the screw when thus freed from the weight of the bridge.

11. The combination with a vertical spindle and a rotatable element thereon provided with a downwardly projecting sleeve spaced from the spindle, of a casing inclosing the said element and provided with a sleeve, the upper end of which is received between the first said sleeve and the pinion, the said casing and the sleeve of the said element having coacting bearing surfaces within the said cas ng.

12. The combination with a vertical spindle and a rotatable element thereon, provided with a downwardly projecting sleeve spaced from the spindle, of an annular oil casing surrounding the said spindle and inclosing the said element, the inner wall thereof being in the form of an uprising sleeve disposed concentrically with the said spindle, the upper end thereof being received in the space between the first said sleeve and the spindle, the said casing being provided with a step bearing below the level of the upper end of the said casing sleeve for engagement with the lower end of the sleeve of the said element.

13. In mechanism of the class described, the combination with an elevating screw, a nut thereon, and a step bearing for the nut, of an inclosing casing having a sleeve therein for surrounding the screw, the upper level of which is above the level of the step bearing, the said casing being adapted to contain oil up to the level of the sleeve, whereby the step bearing will be lubricated but the lubricating material will be prevented from overflowing around the screw.

lt. In mechanism of the class described, the combination with an elevating screw, a nut thereon, a casing for inclosing the said nut, and a step bearing for the nut within the casing removably secured thereto, of a sleeve connected with the casing, surrounding the screw within the nut, and rising to a point above the step bearing, the said sleeve and casing constituting an oil receptacle for maintaining the step bearing flooded with oil while preventing the oil from escaping to the threads of the screw.

15. In mechanism of the class described, the combination with an elevating screw, a

nut thereon, and a step bearing for the nut,

of an inclosing casing for the nut and step bearing, the said casing constituting an oil chamber for containing oil for flooding the step bearing, and having a flanged cupshaped portion above the said nut for containing lubricating material for the threads of the screw, the said casing being open at the bottom to permit the lower end of the screw to pass freely through it.

16. In mechanism of the class described, the combination wit-h an elevating screw, a nut thereon, and a step bearing, of an inclosing casing for the nut and step bearing, the said casing being also provided with an upper bearing for the said nut and provided with means for independently lubricating the threads of the screw, the upper bearing, and the said step bearing.

17. In mechanism of the class described, the combination with an elevating screw, a nut thereon, and worm wheel teeth carried by the said nut, of a worm for engaging the said worm wheel teeth, a casing for inclosing the nut, the worm and the worm wheel, the

shaft of the said Worm being journaled in In Witness whereof, I have hereunto Set the casing, the said casing being divided my hand this 10th day of September5l909. upon two planes transversely connected through the bearing of the Worm Wheel ARTHUR PRESCOTT 5 shaft whereby the worm and shaft may be Witnesses:

moved horizontally from the Worm Wheel HORATIO OKEEFE,

When the casing members are moved apart. D. E. DEUTSOH.

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