US2537234A

US2537234A - Post pulling apparatus

Info

Publication number: US2537234A
Application number: US56888A
Authority: US
Inventors: Osmundson Willard Harding
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-10-27
Filing date: 1948-10-27
Publication date: 1951-01-09
Anticipated expiration: 1968-01-09

Description

Jan. 9, 1951 w. H. OSMUNDSON POST PULLING APPARATUS 2 Sheets-Sheet l 7 Filed Oct. 27. 1948 gvwcm/tom ATTORNEY 4? w MM w MHM$wmW Patented Jan. 9, 1951 POST PULLING APPARATUS Willard Harding Osmundson, Sturgeon Bay, Wis.

Application October 27, 1948, Serial No. 56,888

8 Claims. 1

This invention relate" to a devicefor pulling .p.osts-.or like-chjects'from the ground in which they: are held fast or moored. In particular, the invention relates to a post pulling attachment which is adapted to be secured to the hydraulic lift mechanism of a tractor.

One of the objects of this invention is to provide a post pulling attachment which is simple in construction, ruggedly formed and positive in operation and which carries attached to the lifting means with which it :isemployed with minimal difficulty and without requiring modification of the structure ,of tractor draw links in order to utilize the draw link assembly of a tractor .as the lifting means.

Another object is to provide a post pulling device which isadapted to effectively grip for I removal posts of widely variant diameters without necessitating \a'dustment of the gripping means and which when employed in conjunction with tractordrawn'links permits adjus ments which may be desirable to be made by the operator from his normal operating station.

An importantifeature of the present invention resides in providing ..a post pulling attachment -which does not cause deformation or weakening of the posts which are remcvedby use of the attachment and thereby enables reuse of many posts which otherwise could not be salvaged.

.The invention further provides a gripping element which'isnot dependent on coacting jaws having serrated or other sharpened biting edges which are subject to .dulling for an effective working grip on the postto he pulled.

Other objects and advantages of the invention will-be apparent fromxthe following detailed description when :taken in connection with the accompanying drawings in which:

illustrating the normal position of the ripping arms and in dotted lines the position of the gripping arms in relation to the frame when the post to be pulled is positioned in the gripping ele- "ment.

Figure 3 is a side view showing the attachment assembled on tractor draw links in their :lowered position and a post within the gripping element, and in dotted lines the same assembly in raised position, and

Figure 4 is a diagrammatic view of the post puller.

In general, the post .zpulling attachment com;

prises a frame which adapted for attachment to a lifting means, a pair of gripping arms pivotally mounted on the frame and a length of chain which is fixed to the arms in a manner which forms a gripfor the post to he pulled.

In the embodiment of the invention illustrated in the accompanying drawings iii indicates .a frame of generally U-shaped configuration. The frame is braced against distortion by the ribs i regularly spaced along thelengt-h of the frame.

The extensions or legs 52 of the frame are slightly divergent and formed to lie in generally parallel relationship with thedraw links 53 of a tractor on which the attachment: is assembled. The terminal ends of theextensions l2 are provided with openings A l through which pins [5 extend. The pins-t5 also extend through cor- I responding openings it provided in the draw links it; at the ends thereof. The removable attachment means ,thusprovided retain the ends of the extensions E2 of the frame in fixed relationship with the drawlinks.

Retaining lugs it are formed integrally, or otherwise rigidly affixed, to the'frame forwardly of the pivoted mountings of the extensions 12 and rest on the upper face of the draw links L3. The frame. id is thus suspended in the plane defined between the draw links it! from the. support points provided by the pins 55 the lugs 57.

Lift rods it .are pivotally fixed to the draw links 13 at [9. The lift rods are connected at their oth r ends to the linkage actuated by the hydraulic-lift mechanism of a tractor (not illustrated), the operation of which causes the raisingor lowering of the draw links it and therewith the associated postpuller assembly. Such draw links are employed in tractors utilizing the method .of implement attach-ment and control commonly known as the Ferguson system. Thev attachm nt may be equally well used in connection with pivoted lifting links and lift mechan sm of the type shown in U. S. Patent No.

2,436,510 to Ferguson, dated February 24, 1948.

Pivot plates 2% are rigidly .aifixed to the horizontal flanges of the longitudinal extensions 12 in any suitable manner. The pivot plates are provided with bracket plates .25 in which suitable journals for the shafts 22 are provided. The gripping arms '23 are pivoted on the shafts 22 for axial movement on the said shafts.

The attachment is provided with a gripping element comprising the gripping arms 23 and the chain 2 3.

The gripping arms 23 are provided with the slot 25 in t e r terminal endswhich are adapted \1 to receive a link of the chain 24. The chain is inserted in the slots in a manner which will result in a bight of chain being formed between the upwardly extending gripping arms when the arms are in their normally disengaged position.

The gripping arms are normally held in an upwardly extending position by the action of the springs 26, which are secured at one end to the clevises 21 fixed to the vertical strengthening webs of the arms 23 and at the other end to the plates 20. It has been found that use of a spring tension which results in spacing the terminal ends of the chain supporting gripping arms a distance of approximately 3 inches adapts the attachments for removal of posts varying in diameter in the degree normally encountered without further adjustment. A stop 28 is interposed between the arms 23 and the plate 29 and limits the movement of the arms 23 in upwardly direction about the shafts 22 under the force of the spring 26.

It is apparent from the foregoing description that when the attachment as described is assembled on the draw links of a tractor that the tractor may be backed into position which will allow the post to be received within the open end of the frame between the longitudinal extensions [1. The face of the post first contacting the attachment will cause the gripping arms to rotate upwardly about the shafts in the event that the diameter of the post is greater than the space normally maintained by spring action between the terminal ends of the gripping arms. At this point the forward face of the post will also contact the bight of chain suspended between the gripping arms. Further rearward movement of the tractor will swing the bight of chain backwardly and thus cause it to move upwardly on the post. When the tension on the chain has increased to the point which permits no further upward movement of the chain on the forward face of the post a tendency to rotate downwardly about the shafts 2'2 will be imparted to the gripping arms 23. The catenary defined by the bight of chain is such that this downward tendency will not be imparted to the gripping arms until the diameter of the post has passed within terminal ends of the gripping arms. With the post thus positioned in the grip, as illustrated in solid lines in Figure 3, the hydraulic lifting means is actuated resulting in upward movement of the draw links and the attachment assembled therewith into the position indicated in dotted lines in Figure 3. The upward movement of the attachment will resultin the gripping arms rotating downwardly about their axis of rotation, as from the solid line to the dotted line position shown in Figure 2, thereby tending to force the post rearwardly into the bight of chain as the gripping arms movesdownwardly along the rearward curvature of the post. The chain is thus tensioned to the degree necessary to retain the post at the gripped point and further upwardly movement of the attachment will dislodge the post.

It is apparent that the construction of the gripping element permits ready adjustment for pulling posts of diameters larger or smaller than those to which the gripping element automatically adjusts by positioning the gripping element directly behind and below the normal tractor operating station. The adjustment consists merely of removing the particular link of chain held in the slotted end of a gripping arm and re-inserting a link which will result in the desired catenary.

It is notable that when a post is removed in the manner described, the force necessary to dislodge the post is not applied at localized points but is applied generally throughout the circumference of the post. Deformation of the posts removed is thus minimized and many more posts may be salvaged for re-use than was heretofore possible.

When the post has been dislodged and removed the draw links are hydraulically lowered and the consequent downward movement of the attachment will cause the gripping arms to rotate upwardly about their axi and automatically release the posts from the gripping element.

It is to be understood that although the invention was herein described with reference to a single embodiment thereof, that changes and modifications may be made without departing from the scope of the invention as defined in the following claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. In combination with a lifting means, a post puller comprising a frame secured to said lifting means, two oppositely disposed upwardly extending gripping arms, said arms provided with slots in their terminal ends and pivotally mounted to said frame, and a length of chain adapted to be received in said slots.

2. In combination with a lifting means, a post puller comprising a frame secured to said lifting means, a plurality of upwardly extending gripping arms, said arms pivotally mounted on said frame, and a length of chain fixed to the ends of said arms.

3. In combination with hydraulically operated tractor draw links, a post puller comprising a frame secured to said draw links, two oppositely disposed upwardly extending gripping arms, said arms provided with slots in their terminal ends and pivotally mounted on said frame, and a length of chain adapted to be removably fixed in said slots.

4. In combination with hydraulically operated tractor draw links, a post puller comprising a frame pivotally mounted on the ends of said draw links, retaining lugs on said frame adapted to rest on said draw links, two oppositely disposed upwardly extending gripping arms, said arms provided with slots in their terminal ends and pivotally mounted on said frame, and a length of chain adapted to be received in said slots.

5. A post puller as described in claim 4 comprising two springs, said springs secured at one end to an intermediate section of said arms and at the other end to said frame thereby retaining said arms in their upwardly extending position.

6. A post pulling device comprising a frame, gripping arms pivotally mounted on opposite sides of said frame, fastening lugs fixed to either side of said. frame arranged to operatively engage lifting means disposed beneath said frame, and a gripping chain fixed to the ends of said arms, said chain having a bight intermediate the said ends of said arms sufficient to permit the diameter of a post to be pulled to pass between the arms as the post to be pulled, passing along the longitudinal axis of the frame from the open end thereof toward said chain, moves into engagement with the said chain and causes said arms to be drawn downwardly.

7. A post pulling device comprising a U- shaped frame, oppositely disposed gripping arms pivotally mounted on the respective longitudinally disposed sides of said frame, resilient means connected with intermediate portions of said arms, respectively, and with said frame to yieldingly support said arms in an upwardly extending direction, said arms being provided with slots in their terminal ends, a length of chain adapted to be received in said slots, said chain having a 10 bight intermediate the said ends of said arms suflicient to permit the diameter of a post to be pulled to pass between the arms as the post to be pulled, passing along the longitudinal axis of the frame from the open end thereof toward said chain, moves into engagement with the said chain and, causes said arms to be drawn downwardly.

8. In combination with hydraulically operated tractor draw links, a post puller comprising a frame pivotally mounted on the ends of said draw links, retaining lugs on said frame adapted to rest on said draw links, two oppositely disposed upwardly extending gripping arms, said arms provided with slots in their terminal ends and pivotally mounted on said frame, and a length of chain adapted to be received in said slots, said chain having a bight intermediate the said ends of said arms sufiicient to permit the diameter of a post to be pulled to pass between the arms as the post to be pulled, passing along the longitudinal axis of the frame from the open end thereof toward said chain, moves into engagement with the said chain and causes said arms to be drawn downwardly.

WILLARD HARDING OSMUNDSON.

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

UNITED STATES PATENTS 20 Number Name 7 Date 73,482 Woodworth Jan. 21, 1868 1,709,683 Pollock Apr. 16, 1929