US 2486483 A
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Description (OCR text may contain errors)
Nov. 1, 1949. B. LANDEN FOLDING DRAWBAR FOR SECTIONAL HARROWS Filed May 21, 1945 Bernard Len Idem Patented Nov. 1, 1949 UNITED STATES rATENT OFFICE 2,486,483 FOLDING DRAWBAR FOR SECTIONAL HARROW Bernard Landon, Ida Grove, Iowa Application May 21, 1945, Serial No. 594,917
comprise a central section and end sections hinged or pivoted to the central section for pivotal up and down movement. These draw bars are usually connected with the tractor unit through cables, chains, or the like adapted to be under tension when the sections are in longitudinal alignment. However, on the advance of the draw bar over an uneven ground surface, such that the end sections are pivoted upwardly, the cables connected with the end sections become slack due to the decreased distance between the cable connections on the tractor unit and the cable connections on the end section. As a result the load normally carried by the end section cables is transmitted to the pivoted connections between the end sections and the central section so that the pivoted connections carry the full load or drag on the end sections.
Since this load is applied on the pivoted connection through a simple lever arm having a length corresponding to the length of the end section, the end section is oftentimes bent rearwardly from its pivoted connection, or the pivoted connection is completely broken. Attempts to overcome these diificulties have resulted generally in unwieldy and bulky draw bars which are not too satisfactory in operation, and are clumsy to handle.
It is an object of this invention, therefore, to provide an improved draw bar.
A further object of this invention is to provide a sectional draw bar which is of a construction adapted to maintain the cables, connecting the draw bar end sections with a tractor unit, under tension at upward pivotally moved positions of -the end sections so that such cables always carry a part of the load on the end sections.
A feature of this invention is found in the provision of a sectional draw bar, in which the end sections are movably connected with the central section for up and down pivotal movement and for rearward and forward movement so that cables connecting the end sections with a tractor unit are maintained under a substantially normal tension on upward movement of the end sections relative to the central section, whereby to keep the full load on an end section from being applied on its connection with the central section.
Another feature of this invention is found in the provision of a sectional draw bar in which the end sections are connected with the central section through limited acting universal connections providing for an up and down pivotal movement and a rearward and forward movement of the end sections relative to the central section, and constructed to limit the downward pivotal movement of the end sections to positions in a plane substantially common to the central section. 1
Further objects, features and advantages of this invention will become apparent from the fol lowing description when taken in connection with the accompanying drawings in which:
Fig. l is a perspective view of the sectional draw bar of this invention;
Fig-2 is a sectional view taken on the line 22 in Fig. 1 showing an end section in a moved position; i
Fig. 3 is a detail perspective fragmentary view of the connection between the central section and an end section;
Fig. 4 is a longitudinal sectional view of the connection shown in Fig. 3;
Fig. 5 is a sectional view as seen on the line 5-5 in Fig. 4 showing parts in changed position; and
Fig. 6 is a detail perspective view of the parts forming the connection in Fig. 3, shown in positions providing for their relative assembly.
Referring to the drawings the draw bar of this invention is illustrated in Fig. 1 as including a center section It and end sections ll, of a pipe construction, and provided on their rear sides with hooks 12 for attachment with harrow sections. The end sections I l are connected with the center section III through a ball and socket connection, indicated generally at movement and for rearward and forward movement relative to the center section l2. Since the connections l 3 are similar in construction and operation, only one thereof will be described in detail.
The connection l 3 (Figs. 3 and 6) includes a first connection member I d integrally formed with a cylindrical body member #6 including an annu lar flange 26 at one end provided with an axial extension or neck member ll of a substantially rectangular shape in cross section and having a ball member l8 at its free end. The cylindrical body member I6 is of a diameter adapted to, be received within an outer end of the center section It. As shown in Fig. 4, one side l5 of the neck member I! is of a concave curvature, while its opposite side 20 is of a straight line contour.
A second connecting member 2| (Figs. 3 and 6) 55 of a substantially C-shape in cross section is l3, for pivotal up and down integrally formed with a clamping member 22 adapted to be positioned about the inner end 23 of an end section II, and a socket member 24 at one end of the clamping member 22.
In the assembly of a connection |3 the connecting member I4 is initially inserted within an outer end of the central section l to a position defined by the abutment of the flange 26 (Fig. 4) with the end of the center section Ill. The member I4 is then rotated within the center section l0 until the side 20 of the neck portion I! is positioned at the top of the center section II). This relative position of the connectingmember |4 Within the center section I0 locates the concavely curved side l5 of the neck member I! at the bottom of the center section l il. The member I4 is then suitably fixed on the center section H] by welding or like means.
The connecting member 2| is assembled with the connecting member l4 by initially arranging these members as. shown in Fig; 6 s0 that-the ball member I8 is receivable within the. end 29- of they G-shaped clamp 22 and the neck member t1: within the open side 3| of. the member 2|. The connecting member 2:1; is then. moved relative to the connecting member l4 until the ball member L8; is positioned within the socket member 24. The inner end 23 of an end section is then in:-- serted within the clamping member 22 through its end 29,. after which the member 22 is fixed on the end section H by bolts 32 extended through aligned openings the clamping member 22 andin the end section Referring to Fig. 4, it is seen that the socket member 24 has an end portion. extended inwardly beyond the ball member la and provided with a curved underside 33 adapted for mating engagement with the curved underside I5 of the neck member H to inaintain the end section against downward pivotal movement out of a plane substantially common to: the plane of the center section HI. On upward pivotal movement of anend section the portion 33 is moved away from the neck member ll. as illustrated in dotted linesin Fig. 4. It is seen, therefore, that a ball and socket connection l3, between anend section II and a center section t6, provides for a pivotal movement of. an end section relative to the center section from a position in substantial longitudinal alignment with the center section to an up right position substantially normal to the center section. This upright position is defined by the engagement of the top inner edge 34- of an end section with the top side 20 of the neck member t1.
Also, as best appears in Fig. 5, an end section It is. movable rearwardly and forwardly relative to the center section |n through a limited angle defined by the engagement of the neck member H with the opposite edges 36 of the opening 3| at the top of the socket member 24. In one embodiment of the invention the complete angular movement of an end section relative. ta a center section in a forward and rearward direction is on the order. of about forty-five degrees, that is, about an angle of twenty-two and a half degrees to each side of the center section.
The draw bar is connected with a suitable tractor unit (not shown) by a pair of cables or chains 31 connected at their rear ends with the center section H) by suitable clamps 38 and at their forward ends to a hitch ring 39. The cables 31 are arranged so as to provide fora forward movement of the center section H1 in a plane normal to the line of advance of the tractor unit. A cableor chain 4| is connected between the hitch ring 39 and the forward edge 42 of a brace or support 43 projected forwardly from the front-side of each end section II. The member 43 is of a substantially rod form secured at one end 44 to the outer end of an end section II. From its end 44 the member 43 is extended inwardly and forwardly of the draw bar and then bent rearwardly for connection at 45 with the front side of an end section II, with the rearward bend in the member 43 constituting the forward edge 42. When the draw bar sections l0 and II are in longitudinal. alignment, the cables 31 and 4| are maintained under tension as the tractor unit is advanced.
Draw bars. of the type covered by this invention generally have. their end sections connected with a center section for up and down pivotal movement in the longitudinal plane of the center section as illustrated in dotted lines in Figs. 1 and 2 for an. end section l-l. having a cable 4| connected with the hitch ring, 39., Further, the cable 4 l connecting the end section with a tractor unit usually has its rear end 4(1 attached directly to the front side of the end section Inthe use of these draw bars, therefore, on travel of the end section it over a ground surface. at a-hlgher elevation than. the center section the. end section I! is pivoted upwardly in a straight line movement so that the cable. 4| becomes. slack as also illustrated in dotted lines. in Figs. 1 and 2.
As a result any drag or load on the end section. II. is applied in full on the. pivoted connection 13' between the end section II and the center section. This load oftentimes, is sufficiently great to either bend the end section it rearwardly from its pivoted connection, or break the pivoted connection. Also where the cable 4|. is. attached directly to the front side of an end section loads may be incurred which, during a normal advance. of the end. section in longitudinal alignment with the center section, will bend the end section rearwardly from its point of attachment with, the cable 4| In the operation of the draw bar of this invention, on advance of an end section H, over a ground surface at a higher elevation than the center section Ill,v the end section fl is concurrently pivoted upwardly and moved rearwardly, as illustrated in Fig. 2, by virtue of the ball and socket connection [3. Thus even though the upward pivotal movement of an end section II tends to decrease the distance between the connections of the cable 4| at 42 and at the hitch ring 39, this decreased cable length is accommodated by the rearward movement of the end section II so that the cable 4|. is maintained under tension. A large portion of the load on an end section H is thus carried by a. cable 4| so that the full load. on the end section is not applied on the ball and socket connection [3. In other words, when an end section H is in an upwardly pivotally moved position suflicient rearward movement of the end section takes places. to keep the cable 4| under tension whereby the load on an end section is continuously divided between the. cable 4| and theball and socketconnection. l3. Since the brace rod 43 is connected with an outer end of. an end section H, the rod acts to. hold the section II from. being bent rearwardly at its connection 45. with the brace.
When the center section H) is being advanced over a ground surface at a higher elevation than an end section l 1', the end section is maintained in substantiallythe planeof the center section l0 by the engagement of the coacting portions I5 and 33, in a connection 13, so as to prevent the end section I I from digging into the ground and producing a twisting action on the connection l3.
From a consideration of the above description, it is seen that the invention provides a sectional draw bar which is of a simple and inexpensive construction, light in weight so as to be easily handled, and of a construction adapted to eliminate a breaking failure in an end section connection resulting from the application of a full load or drag on the end section to the connec tion. This is accomplished by providing for a rearward movement of an end section concurrently with its upward pivotal movement so as to maintain the cable connection between the end section and the tractor unit under tension at all times of operation. Thus, although the upward pivotal movement of an end section tends to decrease the distance between the cable connection on the tractor unit and the cable connection on an end section, the rearward movement of the end section concurrently acts to increase the distance between these cable connections. As a result, the rearward movement of an end section compensates for the upward pivotal movement of an end section so as to maintain the distance between the cable connections substantially constant for all upwardly movedpositions of the end section.
Although the invention has been described with respect to a preferred embodiment thereof, it is to be understood that it is not to be so limited since changes and alterations can be made therein which are within the full intended scope of this invention as defined by the appended claims.
1. A draw bar for harrows comprising a center section and end sections, means movably connecting the end sections with said center section for pivotal up and down movement and for rearward and forward movement, means limiting the downward pivotal movement of said end sections to a position in a plane substantially common to said center section, brace structures extended forwardly from said end sections, means connecting said end sections with a tractor unit including flexible means connected between the tractor unit and the forward edges of said brace structures, said flexible means having a tension therein when the sections are in substantial longitudinal alignment, with said tension being maintained on an upward and rearward pivotal movement of said end sections.
2. A draw bar for harrows comprised of a center section and end sections, means movably connecting said end sections to the center section for up and down pivotal movement and for rearward and forward movement including ball members at opposite ends of said center section, neck portions connecting said ball members with the center section, socket members at the inner ends of said end sections adapted to receive said ball members, said socket members having open top sides, and bottom sides extended inwardly for 6 bearing engagement with the underside of said neck portions to limit the downward pivotal movement of said end sections to positions in a plane substantially common to said center section, and means connecting said sections with a tractor unit including flexible means connected with said tractor unit and said end sections, with said flexible means adapted to be under tension when said sections are in said common plane, and said tension being maintained on pivotal and rearward movement of said end sections.
3. A draw bar for harrows including a center section and an end section of a pipe construction, means movably connecting the inner end of said end section and the outer end of said center section for up and down pivotal movement and rearward and forward movement of said end section relative to said center section including a first connecting member receivable in one of said two ends, a longitudinal projection on said first connecting member having a ballportion at the free end thereof, a second connecting member of a substantially c shape in cross section mounted about the other of said two ends having a socket portion adapted to receive said ball portion, with the top side of said 6 connecting member being open and the bottom side of said socket portion adapted for bearing engagement with the underside of said neck portion to limit the downward pivotal movement of said end section to a position in substantially the plane of the center section, and means connecting said two sections with a tractor unit including a flexible means connected with the end section adapted to have a tension therein when the two sections are in longitudinal. alignment, with said tension being retained on pivotal and rearward movement of said end section.
4. A draw bar for harrows comprising a center section and an end section, a ball and socket connection including a ball member on one of said sections and a socket member on the other of said sections for connecting the end section to the central section for pivotal up and down movement and for forward and rearward movement, means including co-acting stop portions on the ball and socket members of said connection for limiting the downward pivotal movement of said end sections to positions in a plane substantially common to said center section, and means for connecting said sections to a tractor unit including flexible means connected with said end sections at positions such that said flexible means are undertension when said end sections are in said common plane and in rearwardly moved positions therefrom.
REFERENCES CITED UNITED STATES PATENTS Name Date Zuger Nov. 26, 1940 Number