US2502108A - Mobile crane - Google Patents

Description

March 28, 1950 w, TAYLOR MOBILE CRANE Filed July 16, 1946 MINI Inventor Patented Mar. 28 1956 OFF'I CE.

MOBILE William Taylor Salford, England? Application July 16, 1946, Serial No. 683,856 In Great Britain September 1, 1945 3 Claims.

This invention relates to improvements in mobile cranes such as are carried by self-propelled motor vehicles.

According to the invention the main jib of a crane is fulcrumed at its rear end on a frame carried by the chassis or other part of the vehicle, and supported at a point intermediate its ends on an auxiliary jib also fulcrumed on the frame a ram operating in an hydraulic cylinder raising or lowering the auxiliary jib which raises or lowers the main jib.

The invention is illustrated diagrammatically in and will be described with reference to the accompanying drawings in which:

Fig. 1 is a side elevation showing the jib in its lowest position;

Fig. 2 is a side elevation showing the jib in its highest position;

Fig. 3 shows a part side elevation of a modification of the mounting of the auxiliary jib on the main jib;

Fig. 4 is a section on line 44 Fig. 3 enlarged.

The main jib A is fulcrumed at its rear end on a frame B carried by the chassis at the rear end of the vehicle. The lower end of an auxiliary jib A is pivoted on the frame B adjacent to the chassis, the fulcrumed end of the two jibs A 3 being substantially separated with the upper end of the auxiliary jib A connected to the main jib intermediate its ends by rollers a engaging runways or guides 11 in the main jib A In the modification shown in Figs. 3 and 4 the main jib A is provided with an inclined surface a of channel shape on its underside the flanges a of which are engaged by flanged rollers a mounted on a shaft a carried by the auxiliary jib A to enable a greater lift to be obtainedor alternatively the same lift with less movement of the auxiliary jib whilst still allowing the main jib to be brought down. to the position shown in Fig. 1.

The hook end of the main jib A may be formed with a series of slots 9 to enable a hook G to be suspended at varying distances from the end.

The auxiliary jib A is connected at a point chassis; a frame mounted on said chassis; a main jib pivoted at its rear end to said frame; an auxiliary jib pivoted to said frame at a point spaced from and below the pivoting point of said main jib; rollers on the free end of said auxiliary jib; flanges forming an inclined surface on the lower face of said main jib; arranged so as to be engaged by said rollers on said auxiliary jib; a hydraulic cylinder member; a motor member operating in said hydraulic cylinder member; first pivoting means pivoting one of said members to said chassis; and second pivoting means pivoting the other of said members to said auxiliary jib whereby movement of said motor member 'within said hydraulic cylinder member will raise or lower said auxiliary jib and thereby raise or lower said main jib too, said inclined surface giving increased lift to said main jib over that imparted by said motor.

2. A mobile crane carried by a movable vehicle comprising in combination a main jib; first pivoting means pivoting said main jib at its rear end to said movable vehicle; an auxiliary jib; second pivoting means pivoting said auxiliary jib at one end to said movable vehicle at a point spaced from and below said first pivoting means in such a manner that the other end of said auxiliary jib engages the lower face of said main jib at a point substantially spaced from said first pivoting means; a hydraulic cylinder member; a piston member operating in said hydraulic cylinder member; third pivoting means pivoting one of said members to said movable vehicle at a point spaced from said first and said second pivoting means; and fourth pivoting means pivoting the other of said members to said auxiliary jib at a point spaced from said second pivoting means whereby movement of said piston member within said hydraulic cylinder member will turn said auxiliary jib about said second pivoting means, which turning movement of said auxiliary jib in turn will result in turning of said main jib about said first pivoting means.

3. A mobile crane carried by a movable vehicle comprising in combination a main jib; first pivoting means pivoting said main jib at its rear end to said movable vehicle; an auxiliary jib; pivoted at its rear end to said vehicle at a point spaced from and below said first pivoting means; roller means freely rotatably mounted on the other end of said auxiliary jib; means forming a supporting surface on the lower face of said main jib arranged at a point spaced substantially from said first pivoting means in such a manner as to be engaged by said roller means; a hydraulic cylinder member; a piston member operating in said hydraulic cylinder member; third pivoting means pivoting one of said members to said movable vehicle at a point spaced from said first and said second pivoting means; and fourth pivoting means pivoting the other of said members to said auxiliary jib at a point spaced from said second pivoting means whereby movement of said piston member within said hydraulic cylinder member will turn said auxiliary jib about said second pivoting means, which turning movement of said auxiliary jib in turn will result in turning of said main jib about said first pivoting means.

WILLIAM TAYLOR. 15

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

UNITED STATES PATENTS Number Name Date 363,066 Harris May 1'7, 1887 503,362 Biehn Aug. 15, 1893 676,504 Kassel June 18, 1901 10 2,019,938 Stephens Nov. 5, 1935 2,342,942 Johnston Feb. 29, 1944 2,395,622 Galbreath Feb. 26, 1946

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