the terms “ left ” and “ right ”, “ up ” or “ upwardly ” and “ down ” or “ downwardly ” are used herein for clarity and ease of description only . they refer to directions as relate to the machine , setting on the ground , facing in the normal direction of travel while in operation . referring now to fig1 for a more detailed description , a pivot tongue harvester 10 is shown . as discussed above in the background of the invention , this is a well - known hay harvester and includes , in pertinent part , a centrally mounted pivot tongue 12 connected to tractor 5 , a header 14 with a cutterbar 16 ( shown in phantom ), and support wheels 20 and 22 . the harvester may be operated in any of the three positions shown in fig1 as 1 , 2 and 3 . for purposes of clarity , fig1 also shows the tractor in the lateral position 4 , which is the position it would be in for pulling the implement after loading onto the transporter . as can be seen , the operable positions when harvesting are anywhere within approximately 45 ° of either side of the tongue when it is parallel to the line of travel of the tractor . therefore , the pivoting range for the tongue is from approximately 45 ° to the left of the centerline , as viewed in this figure , to the transport position in which the tongue is substantially parallel to the header . since the drawbar , or tongue , of the implement is used to pull the load during the transport mode , some other arrangement has to be made for empty movement . fig2 shows the transporter 30 ready for movement without a loaded implement . forward is the direction of travel of the transporter when loaded , which would be to the right in fig2 . reverse is the opposite direction , or the direction that the transporter is moved when unloaded . a secondary tongue 26 attaches to a yoke 53 on the rearmost ramp 60 by pins or bolts 54 and 55 . note that when moving the transporter without the implement , secondary tongue 26 is attached such that the direction of travel is the opposite of that when loaded . referring further to fig2 the basic transporter 30 can be seen to comprise a main frame that includes a longitudinal box beam 32 , a shorter longitudinal box beam 34 held in spaced apart relation to beam 32 by two additional generally transverse box beams 36 and 38 . the main frame is supported for movement by wheel sets 40 and 42 ( in both cases , only one reference number is used to designate the wheel pair ), though single wheels would also provide the adequate support , however , perhaps without the desired load carrying capabilities , especially in wet , muddy field conditions often encountered on the farm . as can be seen more clearly in other figures , a caster wheel 44 is attached to beam 32 at the rear end thereof for additional support during loading and unloading and for assistance in moving the implement tongue 12 from the loading to the transport position . caster wheel 44 is in common usage and standard construction and style . a transporter quite suitable for use with an implement incorporating the invention herein described and claimed is shown in co - pending u . s . patent application ser . no . 09 / 909 , 657 , filed on jul . 20 , 2001 , and entitled “ ramp lock for implement transporter ”. that application is hereby incorporated herein by reference in its entirety . as described in that application , a pair of ramps , 60 and 61 , are pivotably attached to the main frame . attached to the transverse beams 36 and 38 , and extending above the level of the raised ramps , are two header supports and generally flat support plates . when the header 14 of implement 10 is lowered for transport , as will also be discussed further below , the header rests on these support plates . referring to fig3 the pivot tongue harvester 10 is shown in transport position on transporter 30 . the steering link and driveline have been detached ( not shown ) and the centrally mounted pivot tongue 12 has been rotated fully to the side ( when viewed from above ). the pivot tongue is now the device used to pull the load and the secondary tongue 26 has been stowed away . referring now to fig4 the harvester is shown in operational mode connected to the tractor by the pivot tongue . the gearbox 70 is shown pivotably mounted on the header attached to the pivot tongue 12 by the driveline 72 and steering link 74 . during operation , the driveline 72 transfers power from the tractor pto to the gearbox 70 . the gearbox is responsible for the action of the cutterbar and conditioner rolls ( if present ) as outlined in the background of the invention . to ensure the proper operation of the gearbox , the gearbox and driveline must remain aligned while the pivot tongue swings or rotates . to accomplish this , a steering link is utilized to guide the gearbox pivot and maintain the proper angle between the driveline and gearbox . because the pivot tongue and driveline rotate on separate axes , their range of motion when joined is limited . over - rotation of the pivot tongue can result in damage to the driveline , steering link , and gearbox . position 4 represents the position of the pivot tongue when the harvester is in transport position . position 3 , however , shows the maximum permissible rotation of the steering link and driveline before damage occurs . in order to rotate the pivot tongue between positions 3 and 4 , the steering link and driveline must be disconnected from the pivot tongue . as this step may be an easy one to forget , the instant invention acts as a precautionary measure to insure the safety of the driveline . the hydraulic selector valve 80 is shown mounted to the header between the tongue pivot mount and the steering link mount . as the pivot tongue must rotate to the right to reach transport position ( when viewed from above in the normal direction of operation ), the hydraulic selector valve is positioned to the right of the pivot tongue mount in such a way as to make contact with the steering link when the driveline has reached its maximum allowable rotation . a more detailed description of the action of the hydraulic selector valve will follow below . referring now to fig5 the harvester is shown from the right side in the normal direction of operation . the instant invention is clearly visible to the left of the driveline and in front of the gearbox . hydraulic hoses 90 , and 92 are shown entering and exiting the hydraulic selector valve , connecting the valve to the tractor ( not shown ) and the swing cylinder 75 , and , including tube 94 , connecting the swing cylinder 75 to the tractor 5 . these hydraulic hoses are used to fuel the action of the swing cylinder and rotate the pivot tongue 12 through its normal range of motion . the mechanics of the swing cylinder are well known in the art , and the mechanism is well documented in u . s . pat . no . 6 , 360 , 516 . referring to fig6 a close up of the pivot tongue is shown with hydraulic hoses or tubes running the length of the tongue , to and from the hydraulic selector valve and to and from the swing cylinder . as best seen in fig6 a selector valve 80 was placed in the hydraulic circuit between the hydraulic source on the tractor and the tongue swing cylinder 75 . if the operator forgets to disconnect the driveline and steering link from the tongue , the side of the steering link 74 will contact the valve and push it in , thus stopping the flow of hydraulic fluid to the swing cylinder 75 . the tongue will not swing further without the hydraulic fluid and the operator must disconnect the driveline to continue . it will be understood that changes in the details , materials , steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention . the foregoing description illustrates the preferred embodiment of the invention ; however , concepts , as based upon the description , may be employed in other embodiments without departing from the scope of the inventions . accordingly , the following claims are intended to protect the invention broadly as well as in the specific form shown .
a pivot tongue crop harvester , having an hydraulic system to selectively swing the pivot tongue about a pivot point on the harvesting mechanism , including a selector valve to cut off flow of hydraulic fluid to the tongue swing cylinder during loading of the harvester onto a transporter is the driveline of the harvester has not been disconnected .