US2720986A

US2720986A - Tower yarder assembly

Info

Publication number: US2720986A
Application number: US280969A
Authority: US
Inventors: Burton Hobart
Original assignee: WASHINGTON IRON WORKS
Current assignee: WASHINGTON IRON WORKS
Priority date: 1952-04-07
Filing date: 1952-04-07
Publication date: 1955-10-18
Anticipated expiration: 1972-10-18

Description

Oct. 18, 1955 H. BURTON TOWER YARDER ASSEMBLY Filed April 7, 1952 INVENTOR. Hobart Burton United States Patent fifice 2,726,986 Patented Oct. 18, 1955 TOWER YARDF-R ASEMBLY Hobart Burton, Seattle, Wash, assignor to Washington Iron Works, Seattle, Wash, a corporation of Washington Application April 7, 1952, Serial No. 285L969 7 Claims. (Cl. 212-7) yarder assembly in which the tower or spar, as it will be hereinafter termed, connects pivotally with a rotating base and by power derived from the engine of the yarder may be swung vertically from an inactive lowered position into an upright operating position.

It is a still further and particular object to provide a tower yarder assembly in which the tower is given a rigid support when in its upright position by the use of only a minimum number of guy lines.

As a further object still the invention aims to provide an improved tower yarder assembly wherein only the fair-leader for the main line is required to be carried by the spar, and this is to say that the fair-leader for the haul-back line which is also usually carried by the spar is in this instance carried on the head-end of an A-frame which complements the spar.

The invention has the yet further and important object of providing an improved tower yarder assembly including a loading boom in addition to the spar, and wherein such loading boom is pivotally supported from the spar.

A yet further object is to provide a tower yarder of the described nature in which means are provided upon the spar for raising the loading boom from a lowered operating position into and out-of-the-way inactive position.

Other still more particular objects and advantages of my invention and the invention itself will appear and be understood in the course of the following description. The invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawing the single figure is a side elevational view of my perfected tower yarder assembly.

Referring to said drawing, the numeral 5 designates a rotating base mounted for swing motion about a vertical axis on a circular track 6 which surmounts the frame of a crawler truck designated generally by 7, such crawler truck being powered through suitable transfer mechanism from an engine (not shown) which is mounted on a platform which'the rotating base provides. In addition to driving the crawler treads of the truck, and through the usual spur and bull-gear arrangement imparting sluing movements to the base, the engine also serves as the power plant for a plurality of spooling drums carried upon the platform. There are employed, by preference, three of these spooling drums, designated by 8, 9, and 10, and their particular function will become apparent as the description proceeds.

At the front of the rotating base, adjacent each side edge thereof, there is provided a respective chair bracket 11 presenting transverse eyes at the front and rear ends thereof. The two diverging legs of a spar member 12 are pivoted, as at 13, to the forward eyes of these brackets, and to the rear eyes there is connected, by

pins 14, an A-frame 15. This A-frame is made rigid with the base by a pair of stiff-legs 16 which extend diagonally from the head-end of the A-frame to the rear end of the base. At the front of the A-frame adjacent the upper end there is journaled a multiple-groove block 17. i8 designates a link pivotally attached by one of its ends to the head-end of the spar and upon the free end of this link is a multiple-groove block 19.

Blocks

17 and 19 act in complement to take multiple turns of a topping line 28 having one of its ends anchored to the block 19 and having its other end passing about the spooling drum 9.

Made integral with the A-frame and extending upwardly therefrom is a hollow king-pin 38, and journaled for swivel movements on this king-pin is a lower guy ring 34 and an upper self-aligning fair-leader 35. The guy ring accommodates a guy line 36 and the fair-leader accommodates the haul-back line 37 of the logging operatio said haul back line running from the sheave 39 of r-leader downwardly through the hollow center of king-pin and thence over a guide sheave 40 to the spooling drum 8.

Reverting now to the spar it will be seen that there is swivel-mounted at the head-end thereof a fair-leader 39, and passing over the sheave 31 which is provided by this fair-leader is the main line 32 of the logging operation, such main line being handled by the third spooling drum ill. It may be here pointed out that the drawing is deceptive in that it appears from an inspection of the drawing that the main line 32 and the haul-back line 37 lead away from the yarder along opposite paths disposed 180 from one another. The angle between these lines is rarely this wide. in any event, it will be understood that the outer end of the haul-back line connects with the outer end of the main line, customarily passing at the outer limits of the lead operation first through one and then another of two separated haulback blocks (not shown). A single guy line 33, connecting with the head end of the spar and extending rearwardly therefrom, braces the spar against load forces carried thereto from the main line.

Now considering the loading boom, which I designate by 42., the root end thereof is pivotally connected, as at 43, to the spar, and there is provided upon the outer end of this loading boom a self-aligning fair-leader 44. The sheave 45 of this fair-leader accommodates a loading line 46, such loading line passing from the sheave 45 over a guide sheave 48 and thence to the platform of the rotating base. A feature of considered importance is the ability to employ the spooling drum 10 both for the main line 32 and for the loading line 46, inasmuch as these two lines are employed alternatively. Each of the two lines carries a ferrule, as 47, upon the inner end thereof, and this ferrule slips into a keyhole slot presented along the spooling surface of the spooling drum. A like or similar keyhole slot may, if desired, be provided in a wall of the deck-carried house 49 so as to hold the free end of whichever line is not connected to the spooling drum. In the drawing I have broken away a portion of the operators cab 53 to permit a full-line illustration of such a slot.

A trace cable 56 dropped from the head-end of the spar to the outer end of the boom gives support to the latter when the same is being used in the performance of its loading function. When not being used, it is desirable that the loading boom occupy a raised position closely underlying the tower, as shown by dotted lines in the drawing, and for performing this elevation of the boom there is provided a hydraulic hoist 51 connecting by a cable 52 with the outer end of the boom.

By means of the construction and arrangement of parts, it will be apparent that I have provided an unusually simple piece of logging equipment which will effectively handle the work of yarding and loading logs. When the machine is being used for loading it is apparent that the main line will be slacked off whereupon the rotating base is free to rotate about the crawler-mounted foundation.

It will be noted that the common axis about which the guy ring 34 and the fair-leader 35 swivel coincides with the sluingaxis of the base;

that the hereto annexed claims be given a scope fully commensurate with the broadest interpretation which the employed language fairly permits.

What I claim is:

1. In a tower yarder assembly, a vehicular mount, a base carried for rotation by said mount, a spar having its foot pivotally supported by the base, an upright Aframe lying to the rear of the spar and having its foot pivotally supported by the base adjacent the foot of the spar, a pair of stiff-legs attached one end to the upper end of the A-frame and the other end to the base'at a point rearwardly removed from said pivotal foot of the A-frame, enginedriven spooling drums carried by the base, sheaves carried by the spar and by the A-frame at the head ends thereof, a rearwardly extending guy line bracing the headend of said spar, a loading boom pivoted by one end to the spar at a point intermediate the ends of the latter and extending by its free end forwardly from said spar, a trace line dropped from the head-end of the spar to the free end of said loading boom for suspending the latter, a loading line powered from one of said spooling drums, and a self-aligning fair-leader swiveled upon the free end of the loading boom and serving to accommodate said loading line, said loading line and the main logging line each admitting to being detachably connected 7 with a single said spooling drum for powering the main line and the loading line alternatively.

2. In a tower yarder assembly, a vehicular mount, a base carried for rotation by said mount, a spar having its foot pivotally supported by the base, an upright A-frame lying to the rear of the spar and having its foot pivotally supported by the base adjacent the foot of the spar, a pair of stiff-legs attached one end to the upper end of the A-frame and the other end to the base at a point rearwardly removed from said pivotal foot of the A-frame, enginedriven spooling drums carried by the base, sheaves carried by the spar and by the A-frame at the head ends thereof, a rearwardly extending guy line bracing the headend of said spar, a loading boom pivotedby one end to the spar at a point intermediate the ends of the latter and extending by its free end forwardly from said'spar,

a trace line dropped from the head-end of the spar to the free'end of said loading boom for suspending the latter, a hydraulic hoist carried by the spar, and a hoist line extending from said hoist to the free end ofthe loading boom for raising the loading boom into an elevated inactive position closely underlying the spar.

t 3. In a tower yarder assembly, a mount, a base supported ,by said mount for sluing movements about a vertical axis, engine-driven spooling drums carried by said base, a pivotally mounted spar footing upon the base and swingable vertically from an inactive lowered position into an erected operating position whereat the spar tilts forwardly from the vertical, means operated by activation of one of said spooling drums for raising the spar, means at the head end of the spar accommodating the attachment of a rearwardly extending guy line, a self-aligning fair-leader swiveled upon the head-end of said spar and serving to accommodate a main logging line which is powered by another of the spooling drums, a loading boom pivoted by one end to the spar ata point intermediate the ends of the latter and extending by its free end forwardly from said spar, means dropped from the head-end of the spar to the free end of said loading boom for suspending the latter, a hydraulic hoist carried by the spar, a hoist line extending from said hoist to the free end of the loading boom for raising the loading boom into an elevated inactive position closely underlying the spar, and a self-aligning fair-leader swiveled upon the free end of the loading boom and serving to accommodate a loading line having its inner end powered by one of said spooling drums.

4. In a tower yarder assembly, a crawler mount, a base supported by said mount for sluing movements about a vertical axis, an engine and engine-driven spooling drums carried by said base, a spar having a pivotal connection with the base permitting the spar to swing vertically about a transverse horizontal axis from an inactive lowered position into an erected operating position whereat the spar tilts forwardly from the vertical, an A-frame carried by and made rigid with the base in a position to the rear of the spar and provided at its head-end with an upstanding hollow king-pin, a guy-ring and a self-aligning fair-leader each swivel-mounted upon said king-pin, said guy-ring accommodating a rearwardly extending guy line and said fair-leader accommodating the haul-back line of the logging operation with the inner end of said haul-back line passing downwardly through the hollow center of the kingpin to one of the spooling drums, a multiple-groove block carried at the head-end of the A-frame on the front side thereof, a complementing multiple-groove block carried from the head-end of the spar, a topping line having several turns thereof passing around said complementing blocks and carried to another of said spooling drums, means at the head-end of the spar accommodatingthe attachment of a rearwardly extending guy line, a self-aligning fair-leader swiveled upon the head-end of' said spar and serving to accommodate a main logging line which is powered by still another of the spooling drums, a loading boom pivoted by one end to the spar at a point intermediate the ends of the latter and extending by its free end forwardly from said spar, a trace line dropped from the head-end of the spar to the free end of said loading boom for suspending the latter, a hydraulic hoist carried by the spar, a hoist line extending from said hoist to the free end of the loading boom for raising the loading boom into an elevated inactive position closely underlying the spar, and a self-aligning fair-leader swiveled upon the free end of the loading boom and serving to accommodate a loading line having its inner end powered by one of said spooling drums.

5. Structure according to claim 4 in which the axis about which the guy ring and the first-named fair-leader swivel coincides with the sluing axis of the base.

6. Structure according to claim 4 in' which the loading line and the main logging line each admit of being detachably connected with a single said spooling drum for powering the main line and the loading line alternatively.

7. In a tower yarder assembly, a rotative base, a spar having its foot pivotally supported by the base, an upright A-frame lying to the rear of the spar and having its foot pivotally supported by the base adajacent the foot of the spar, a pair of stiff-legs attached one end to the upper end of the A-frame and the other'end to the base at a' point rearwardly removed from said pivoted foot of the A-frame, engine-driven spooling drums carried by'the base,

block-and-tackle means powered from one of the spooling drums and connecting the head-end of the spar to the head-end of the A-frame for raising the spar into erected operating position, a rearwardly extending guy line bracing the head-end of said erected spar, a sheave carried by the spar at the head-end thereof, a loading boom pivoted by one end to the spar at a point intermediate the ends of the latter and extending by its free end forwardly from said spar, means dropped from the head-end of the spar to therfree end of said loading boom for suspending the latter, and a loading line for said loading boom powered References Cited in the file of this patent UNITED STATES PATENTS 1,195,461 Greene Aug. 22, 1916 6 Bradney et a1 Jan. 21, 1919 Remde Feb. 25, 1930 Swenson Apr. 29, 1930 De Vou Sept. 5, 1933 Huot Dec. 24, 1935 McGiifert et al. Sept. 27, 1938 Russell Mar. 13, 1951 Shoemaker May 6, 1952