US2470998A - Portable mast - Google Patents

Description

May 24, 1949. R. H. McPHERSON 2,470,998

PPPPPPPPP ST Filed Oct. 8, 1945 3 sheets'shee 1 691 A 69b l9 l9 Wm Imam l gr i 2| mmlllm /6 I I4 V l8 INVENTOR,

ROBERT H. McPHERSON ATTORNEY May 24, 1949. R. H. MCPHERSON PORTABLE MAST 3 Sheets-Sheet 2 Filed Oct. 8, 1945 ZOE-0mm mzOEbmm mum May 24, 1949. R. H. MCPHERSON 2,470,993

PORTABLE MAST Filed Oct. 8, 1945 3 Sheets-Sheet 3 I INVENTOR. ROBERT H. MQPHEBSON ATTORNEY Patented May 24,1?49

PORTABLE MAST Robert H. McPherson, Lynwood, Calif. Application October 8, 1945, Serial No. 621,105

1 Claim.

It is therefore an object of the invention to provide a portable derrick which may be reduced in overall size without disassembling, so that it may be readily raised or lowered and may also be readily transported from one site to another by road or highway on ordinary trucks or trailers.

In the present invention, in order to accomplish the above object. the mast embodying said present invention is provided with two legs and is so arranged that the legs are hinged at the top. The device is also so constructed and arranged that each leg comprises a plurality of sections with the sections telescoping together.

A further feature of the invention relates to the means for extending or telescoping the respective sections of each leg. This means, in said present invention, isso arranged that the upper section, besides being extended by said means, will be held in an elevated position in case of failure of the operating mechanism. this result being effected by means of a worm and worm gear system.

Another feature of the invention resides in the novel arrangement whereby the operating mechanism for extending the upper section of each leg includes, chains adjacent the sides of the lower sections and said chains are secured adjacent the ends thereof to the extremities of said bottom sections. the operating mechanism having sprockets engaging the chains. The chains are also adjustable so that the links thereof will be p in substantially the same planes.

Another object ofthe invention is to provide means for stopping the extension of the upper section when it reaches the desired position with respect to the lower section.

In connection with the raising of the structure from a prone to an upright position or vice versa. the invention possesses certain advantages. particularly in the relative ease with which the device may be so raised or lowered. As shown herein, and more fully described hereinafter, the

present structure. is susceptible of being raised from a prone position to an upright position when the legs are in the telescoped position. For example, in raising the mast, the free ends of the legs are separated and are moved into position on a support, there being a ball and socket arrangement for pivoting the mast during this operation. When the device is raised to the upright position the respective sides of each of the legs are supported by the ball and socket connection and by a support member of the base. Due to the angular relationship of the device when telescoped, the opposite sides of the legs are spaced somewhat from other supporting members of the base. After the mast has been raised to the upright position, the telescoped members are extended, and when extended the angular relationship of the legs, .relative to the base, changes so that the last mentioned sides of the legs are supported by said other support members.

Further objects and advantages of the invention will appear in the following part of the specification. R

Referring to the drawings which are for illustrative purposes only,

Fig. 1 is a side elevation of the mast in its operative extended position, the device being shown diagrammatically;

Fig. 2 is a view similar to Fig. 1, but taken at right angles there-t0;

Fig. 3 is a diagrammatic side view showing the mast telescoped and in a prone position preparatory to raising same to an upright position, the

latter position being shown in dotted lines in this figure;

Fig. 4 is a diagrammatic view taken on line 4-4 of Fig. 3; v

Fig. 5 is a diagrammatic side elevation of one telescoped legof the structure;

Fig. 6 is a. plan view taken on lines- 6 of Fig. 5, and diagrammatically shows the mechanism for extending the telescoping sections of the leg; Fig. 7 is a view taken on line 1--1 of Fig. 6, and

tion I! in telescoping relationshipwith anupper section I3 which, as shown, telescopes within the lower section. said sections being shown as generally rectilinear in cross section. The lower Fig. l is a partial side viewshowing the switch sections are supported on a base i4 of any suitable well-known character, and each leg is provided with a ball I! adjacent an inner bottom corner of the lower member, the ball being received in a socket II of a socket member i'l secured to the base II. The outer corners of the lower end of each leg are supported by support members II, the inner corners, opposite the balls i5 restins on supports which are omitted from Figs. 1, 4 and 5, in order to more clearly show the ball and socket construction. Supports i8 on, the base 14 are adapted to support the outer sides of the lower end of said leg sections II. The top sections II are provided with hinged members l9 pivoted adjacent their ends on a shaft 20, the structure at the top of said members l3 being considered as the crown. As shown in Figs. 1 and 2, pipe rack means, indicated generally at 2|, is provided for racking lengths of pipe 22, and stabilizing means are provided, said means comprising guy wires or cables 23 are attached to the corners of the crown and anchored in the ground.

Means for extending or telescoping each leg is provided, and as shown in Figs. 5 to 7 inclusive,

include a frame 24 mounted adjacent the lower end of the upper section l3, and having a plate 25 on which is supported an electric motor 26 which has pulleys 21 which are connected with pulleys 23 by V -belts 29, the pulleys 28 being supported by a shaft 30, journaled in an extension 3| of a housing 32. With this arrangement it is desirable to synchronize the motors of the respective legs. Speed reduction mechanism includes a worm 33 on the shaft 30 which operates a worm gear 33 fixed to a shaft 34 journaled in the housing 32. The worm and worm gear arrangement, besides providing speed reduction means, also provides means whereby the upper section will be prevented from telescoping after it has been extended to the desired position, or in case of failure of the operating mechanism while in a position intermediate the telescoped and extended positions.

Means for converting the rotary motion of the shaft 34 into longitudinal movement of the upper section I3 is shown as comprising a chain 35 at each side of each lower section II, each chain having its upper end secured at 35 to the lower section I2 adjacent the upper end thereof. The lower end of each chain is secured at 31 to the lower section adjacent the lower end thereof. Each chain is disposed between the adjacent sides of the upper and lower sections when telescoped. Anchoring and adjusting means for each chain includes a segmental gear 39 on a shaft 40, adjacent the upper end of section I2, about which the chain is passed, said shaft 40 being supported adjacent oneend of the lever 4| which is pivoted on a shaft 42, intermediate its ends, said shaft being secured to a flange 42 of the upper end of the lower section l2. Means for adjusting the lever 4| is provided and comprises an eye bolt 42a which is attached at 43 to the lower end of the lever 4i passes through a link of the chain, and is received in an ear 44 secured to the upper end of the lower section l2. A nut 45 is threadably received on the free end of the bolt. Should it be desired to adjust the length of the chain, the eye bolt may be removed from the link in which it is received, and the segmental gear 33 is rotated to take up any slack in the chain, and thereafter the bolt 42a is replaced in the ear 44, thereby holding the chain in the adjusted position. Thus the individual chains may be adjusted so that the links of the chains will be in the same planes,

thereby insuring that the upper sections will be properly aligned relative to each other and to their respective lower sections.

The shaft 34 is journaled adjacent its outer ends in support members 50, and said outer ends extend beyond said support members and carry sprockets 5| which operably engage the chains. In order to insure a positive and secure connection between the sprocket 5| and the respective chains, each supporting member 53 is provided with an extension 52 having an arcuate slot 53 therein, receiving a reduced end portion 54 of a shaft 55 on which is rotatably mounted an idling sprocket 56 over which the chain is passed, as best shown in Fig. 5. The position of the shaft 50 in the slot 53 is adjusted to the proper position considering the slack in the chain, and is held in the adjusted position by a nut 51 threadably received on the reduced end 54 and drawing the shoulder 58 on the shaft tightly against the adjacent side of the extension 52.

In elevating the upper sections of the legs, the motors 25 are energized, there being suitable electric connections 58 to the motor from a suitable source of electrical supply, not shown. Each motor then operates the shaft 34 through the-reduction mechanism hereinabove described, and as the shaft 34 is rotated the sprockets 5| move upwardly on the chain 35, thus efl'ecting extension of the upper section. It may be desirable to provide means for stopping the motors when the upper sections reach the desired extended position and this is effected by providing a switch which will be open when the upper section reaches said position. As shown in the drawings, the switch indicated at 53 in Figs. 6 and 8, is located adjacent the top of the lower section and between said section and the upper section. The switch is provided with a plunger 60 which is adapted to be engaged by a bracket 6| suitably located adjacent the lower end of the upper section. when the upper section reaches the desired position hereinabove mentioned. The two sections are then secured together by any suitable means such as bolts, not shown.

The motor 26 may be of the reversible type, so that the sections i2 and I3 may be telescoped by reverseaction of said motor.

When it is desired to erect the mast after it has been transported to a site where it is to be used, the lower end is moved to a position over the base l4 on which it is to be supported while the structure is in the prone position, and the free end of the legs pivotally separated, it being understood that the sections of the legs are telescoped. Means for pivoting the mast on the base is provided, and as shown, comprises the socket member I! for each leg, which is secured to the base i4. The sockets are spaced apart on the base and the ball IS on each leg is positioned in the respective sockets, these balls being attached to the lower end of the lower section at the adjacent inner corners thereof.

Suitable means for raising the structure to an upright position is provided, and as shown, comprises a cable and pulley arrangement of any suitable character including cable 53a, a traveling block 69, sheaves 59b on the crown, and a winch 10 mounted on the base l4, said winch being operated by any suitable means, not shown. A cable 'H has its ends secured to the lower section of the legs at a suitable point intermediate the ends thereof, as at 12. The cable ii is passed over sheaves 13 mounted on a shaft 14 which is supported frame member 15, also mounted on the block ll. The central portion of the cable H is passed over a hook it of the traveling block '8. When the winch 10 is actuated, the traveling block moves toward the upper or free end of the structure and exerts a force on -the cable H which will cause the structure to be raised to the upright position shown in dotted lines in Fig. 3, the supports 18 not being shown in this view in order to more clearly show the supporting means just described. When in the upright position, before the upper sections of the legs are extended, the inner bottom side of each leg is supported by the balls and socket members I5, l1, and by supports 11 at the opposite inner corners. The outer sides of the lower end of each leg opposite the ball and socket and support 11, are spaced upwardly from the supports l 8, as shown in Figs. 4 and 5, which are so located that when the upper sections of the legs are extended, these supports II will be engaged by the adjacent portions of the lower legs, as shown in Fig. 1, due to the change in the angular relationship of the legs with respect to the plane of the base. Should it be desired to lower the structure to a prone position for transporting same to another site, the foregoing steps are reversed.

I claim:

In a portable mast of the class described, comprising: a pair of legs, each leg comprising an upper and lower section of generally rectilinear cross-section, said sections being so constructed and arranged that the sections will telescope together; means hinging the upper sections together adjacent their upper ends; pivoting members on adjacent inner corners of one side of the mast; complementary supporting members fixed to a base; supporting members for the opposite inner corners for supporting the mast when it is raised from a prone to an upright position while the leg sections are telescoped; and supporting means for the outer sides of the lower ends of the lower sections when the legs are extended.

ROBERT H. MCPHERSON.

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

UNITED STATES PATENTS Number Name Date 289,119 Metzger Nov. 27, 1883 670,674 Hutchings Mar. 26, 1901 849,222 Fleming Apr. 2, 1907 1,470,292 Scheunert Oct. 9, 1923 2,191,181 Rogers Feb. 20, 1940 2,252,166 Clawson et al. Aug. 12, 1941 2,283,049 Cornier May 12, 1942

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