Wrapper trip mechanism

Abstract: A roll baling machine 10 includes a main frame 12, a tailgate 16 pivotally connected to the main frame 12, and an apron 34 extending around a plurality of guide rolls 40, 42, 44 disposed in the main frame 12 and in the tailgate 16. A pair of take-up arms 46 are rotatably mounted in the tailgate 16 and carry an additional guide roll 48 for the apron 34. A pair of levers 52 are connected to rotate with the take-up arms 46, and springs 56 are connected to the levers 52 to urge the take-up arms 46 into a bale starting position. The machine is provided with a twine wrapper, and a mechanism for automatically tripping the twine wrapper into operation comprises a cam surface 52a on one of the levers 52 engageable with a cam roller 60 carried on a first link 62. This first link 62 is rotatably mounted on the main frame 12 and is connected to a sliding member 74 which is movable toward and away from a tripping position. The tripping mechanism also includes second, third and fourth links 64, 66, 72 connecting the first link 62 to the sliding member 74. When the tailgate 16 is raised, the cam surface 52a on the one lever 52 is moved out of engagement with the cam roller 60 on the first link 62 to prevent improper tripping of the twine wrapper.

Description: This invention relates generally to roll baling machines which form cylindrical bales of crop material, typically referred to as "round balers", and, in particular, to a wrapper trip mechanism for such machines. US-A-4,771,595 discloses a round baler having a plurality of rollers that cooperate with an apron consisting of a plurality of belts to form cylindrical bales. Take-up arms for the apron are rotatably mounted in a tailgate of the baler. Consequently, the take-up arms are lifted whenever the tailgate is raised. Mounting the take-up arms in the tailgate causes a problem when a conventional type of automatic twine wrapper such as disclosed in US-A-4,167,844 is installed on the baler of US-A-4,771,595. This type of twine wrapper is automatically tripped into operation by the apron take-up arms as they rotate during bale formation. However, with the type of twine wrapper disclosed in US-A-4,167,844 installed on the baler disclosed in US-A-4,771,595, the apron take-up arms will improperly trip the twine wrapper into operation whenever the tailgate is raised. Such improper tripping of the twine wrapper is undesirable. It is the object of the present invention to provide a solution for the above discussed problem and this solution is obtained by the combination defined in the appended claims in general and the appended main claim in particular. The present invention provides a mechanism for automatically tripping a wrapper, such as a twine wrapper, into operation on a roll baling machine which has a main frame, a tailgate pivotally connected to the main frame and an apron extending around a plurality of guide members disposed in the main frame and the tailgate. A pair of take-up arms are rotatably mounted in the tailgate and carry a further guide member for the apron. The take-up arms have a bale starting position. A lever is connected to rotate with the take-up arms, and spring means are connected to the lever for urging the take-up arms into their bale starting position. The tripping mechanism comprises a cam surface on the lever engageable with a cam roller carried on a first link. The first link is rotatably mounted on the main frame and is connected to a sliding member which is movable toward and away from a tripping position. A round baler in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings in which: Fig. 1 is a side elevation view, taken at the start of bale formation, of a round baler incorporating the preferred embodiment of a twine wrapper trip mechanism according to the present invention; Fig. 2 is an enlarged side elevation view of the round baler of Fig. 1 taken near the end of bale formation; Fig. 3 is an enlarged side elevation view of a portion of the round baler of Fig. 1 taken as a completed bale is being discharged; Fig. 4 is an enlarged side elevation view of part of the twine wrapper trip mechanism shown in Figs. 1, 2 and 3; and Fig. 5 is a top plan view of the part of the twine wrapper trip mechanism shown in Fig. 4. Referring to Fig. 1, a round baler 10 includes a main frame 12 supported by a pair of wheels 14. A tailgate 16 is pivotally mounted on the main frame 12 by stub shafts 18, and a tongue 20 has one end fixedly attached to the main frame 12 while the other end of the tongue 20 is adapted for attachment to a tractor (not shown). A pickup device 22 is supported by a pair of wheels 24 for lifting crop material from the ground and moving it toward a floor roller 26. A series of rollers 28, 30, 32 cooperates with the floor roller 26 and with an apron 34 which consists of a plurality of belts arranged side-by-side to define an expandable bale forming chamber. Rollers 28 and 30 are mounted in fixed positions adjacent each other but roller 32 is carried by a pair of sledge arms 36 which pivot on shaft 38 of roller 30. The apron 34 extends around guide rolls 40 and a drive roll 42. An additional guide roll 44 for the apron 34 is carried on the sledge arms 36, and a pair of take-up arms 46 carry another guide roll 48 around which the apron 34 extends. The drive roll 42 is driven in a counterclockwise direction in Fig. 1 thereby causing an inner run of the apron 34 extending between the lowermost guide roll 40 and the drive roll 42 to travel upwardly and forwardly as a bale is being started in the bale forming chamber. Rollers 28, 30, 32 are also driven in a counterclockwise direction in Fig. 1 to assist the apron 34 during bale formation. Power for driving the rollers 28, 30, 32 and the drive roll 42 is supplied by a drive shaft 21 which is connected to a tractor PTO. The take-up arms 46 are fixed to a cross shaft 50 which is rotatably mounted in the tailgate 16. A pair of levers 52 are also fixed to the cross shaft 50 to rotate with the take-up arms 46, and straps 54 are connected between the levers 52 and springs 56. The springs 56 are anchored to brackets 58 mounted in the tailgate 16. It will be understood that the springs 56 act to urge the take-up arms 46 into a bale starting position shown in broken lines in Fig. 1 and to resist upward movement of the take-up arms 46 away from their bale starting position. This action of the springs 56 maintains tension in the apron 34 during bale formation. According to the present invention, one of the levers 52 has a cam surface 52a formed thereon which contacts a cam roller 60 carried on the upper end of a first link 62. The lower end of the first link 62 is pivotally connected to one end of a second link 64 while the other end of the second link 64 is pivotally connected to the upper end of a third link 66. A pin 68 carried on the lower end of the third link 66 is disposed in a slot 70 formed in one end of a fourth link 72. The other end of the fourth link 72 is pivotally connected to a sliding member 74 which activates a twine wrapper (not shown) on the round baler 10. This twine wrapper may be of the type disclosed in US-A-4,167,844, incorporated herein by reference. The links 62 and 66 are rotatably mounted on stub shafts 76 and 78, respectively, which are carried on the main frame 12, and a tension spring 80 is connected between the fourth link 72 and a bracket 82 on the main frame 12. Referring to Figs. 4 and 5, the sliding member 74 has a base 75 with a finger 84 at one end and a hook 86 adjacent the other end thereof. A pair of upstanding tabs 88 are fixed to the base 75 of sliding member 74 for receiving a bolt 90 which pivotally connects the link 72 and the sliding member 74. An elongated slot 92 in the base 75 of sliding member 74 receives a sleeve 94 through which a bolt 96 extends. A nut 98 and a lock washer 100 secure the bolt 96 to a flange portion 102 of a support bracket 104 on the main frame 12 of round baler 10. A flat washer 106 is disposed between the upper end of the sleeve 94 and the head of bolt 96. A lower leg 87 of the hook 86 extends underneath the support bracket flange portion 102 to assist in guiding back and forth movement (i.e. left and right in Figs. 4 and 5) of the sliding member 74 relative to the support bracket 104. The finger 84 has a straight portion 84a that is welded to the base 75 of sliding member 74 and an angled portion 84b that extends rearwardly and upwardly with respect to the straight portion 84a. The elongated slot 92 limits the back-and-forth movement of the sliding member 74 while the flat washer 106 limits upward tilting movement of the sliding member 74. When the sliding member 74 is moved to the right in Figs. 4 and 5 toward a tripping position, the angled portion 84b of finger 84 engages a bracket B on a plate P that is rotatably mounted on a shaft S. It should be understood that the plate P, which forms no part of the present invention, is designated as "trigger cam plate 72" in US-A-4,167,844. Likewise, bracket B is designated as "side bracket 77" and shaft S is designated as "shaft 80" in this US-A-4,167,844. Engagement of the finger angled portion 84b with the bracket B causes counterclockwise rotation of the plate P in Fig. 5 about the shaft S. This counterclockwise rotation of the plate P activates a twine wrapper (not shown) as described in US-A-4,167,844. The parts designated as "roller arm 51" and "roller bearing 54" in US-A-4,167,844 are replaced by the sliding member 74 and finger 84, respectively, of the present invention. At the start of bale formation, the round baler 10 will be in the condition illustrated in Fig. 1 with the apron take-up arms 46 in their bale starting position shown in broken lines and the cam surface 52a on lever 52 contacting the cam roller 60. The links 62, 64, 66, 72 and the sliding member 74 are urged into the positions shown in Fig. 1 by the spring 80. During bale formation, the apron take-up arms 46 move upwardly away from their bale starting position as the inner run of the apron 34 extending between the lowermost roller 40 and the drive roller 42 expands in length. This upward movement of the apron take-up arms 46 causes rotation of the cam surface 52a which remains in contact with the cam roller 60 thereby resulting in rotation of the link 62 in a clockwise direction in Figs. 1 and 2. When the apron take-up arms 46 reach a full bale position, the links 62, 64, 66, 72 and the sliding member 74 are moved into the tripping positions shown in full lines in Fig. 2 and the finger 84 on the sliding member 74 engages the bracket B on plate P and automatically trips the twine wrapper (not shown) into operation. Since the length of the second link 64 is adjustable, the tripping position of the sliding member 74 may be adjusted as desired. Once a bale has been wrapped with twine, the tailgate 16 is raised as illustrated in Fig. 3 and the wrapped bale is discharged from the round baler 10. As the tailgate 16 is raised, the cam surface 52a on lever 52 is moved out of engagement with the cam roller 60 on link 62. This prevents the finger 84 on sliding member 74 from being moved into engagement with the bracket B on plate P. Therefore, the twine wrapper will not be improperly tripped into operation by the sliding member 74 when the tailgate 16 is raised.

Claims: A round baler (10) of the type having a main frame (12), a tailgate (16) pivotally connected to the main frame (12) for movement between bale forming and bale discharge positions and an expandable bale chamber delimited, at least in part, by bale forming means (34) which, during bale formation, gradually move outwardly to provide for bale chamber expansion; said baler (10) further also including wrapper means for wrapping a completed bale in the bale chamber with wrapping material and a mechanism extending between the tailgate (16) and the main frame (12) and operatively associated with the bale forming means (34) and the wrapper means for automatically tripping said wrapper means into operation when a bale which is being formed in the bale chamber, reaches its final size, and characterized in that the wrapper tripping mechanism includes a cam surface (52a) operatively connected to the bale forming means (34) and a cam follower (60) operatively connected to the wrapper means; said cam surface (52a) being disposed to engage with the cam follower (60) for transmitting a tripping signal from the bale forming means (34) to the wrapper means when the tailgate (16) is in its bale forming position and a bale in the bale chamber reaches its final size and, to move out of engagement with said cam follower (60) when the tailgate (16) moves toward its bale discharge position. A round baler (10) according to claim 1 wherein the bale forming means comprise an apron (34) extending around a plurality of guide means (40, 42, 44) disposed in the main frame (12) and the tailgate (16) and take-up means (46, 50, 52, 54, 56) for taking up excessive apron length when the apron (34) is in a bale starting position and resisting, during bale formation, movement of the apron (34) away from the bale starting position to a full bale position to thereby maintain tension in the apron (34) and which is characterized in that the wrapper tripping mechanism operatively is associated with said take-up means (46, 50, 52, 54, 56). A round baler (10) according to claim 2, characterized in that: the take-up means (46, 50, 52, 54, 56) and the wrapper means respectively are provided in the tailgate (16) and the main frame (12); the cam surface (52a) is operatively connected with the take-up means (46, 50, 52, 54, 56) in the tailgate (16) and, the cam follower (60) is operatively connected with the wrapper means in the main frame (12). A round baler (10) according to claim 3 wherein the take-up means comprise arm means (46) rotatably mounted in the tailgate (16) and carrying further guide means (48) around which the apron (34) extends; said take-up means further also comprising spring means (56) for urging said arm means (46) toward a bale starting position and resisting movement thereof away from said bale starting position toward a full bale position and said baler (10) being characterized in that the cam surface (52a) operatively is coupled to said arm means (46) for pivotal movement in unison therewith and the cam follower (60) operatively is coupled to the wrapper means for transmitting any tripping signal received from the cam surface (52a) thereto. A round baler (10) according to claim 4, characterized in that: the take-up means comprise a lever (52) connected at one end to the arm means (46) to rotate in unison therewith and connected at the other end to said spring means (56) in a manner so that these spring means (56) urge said arm means (46) into said bale starting position, and the cam surface (52a) is provided on said lever (52). A round baler (10) according to any of the claims 3 to 5, characterized in that the cam follower is in the form of a cam roller (60) carried on linkage means (62, 64, 66, 72) mounted on the main frame (12) for movement toward and away from a tripping position. A round baler (10) according to claim 6, characterized in that spring means (80) operatively are associated with said linkage means (62, 64, 66, 72) for urging these linkage means (62, 64, 66, 72) away from said tripping position. A round baler (10) according to claim 6 or 7, characterized in that said linkage means comprise first, second, third and fourth links (62, 64, 66, 72) of which: the first link (62) rotatably carries said cam roller (60) at one end thereof; the first and third links (62, 66) rotatably are mounted on shafts (76, 78) on the main frame (12); the second link (64) pivotally is coupled, at its opposite ends, to corresponding ends of the first and third links (62, 66) and is adjustable in length; the third link (66) carries, at its other end, a pin (68) which engages in a slot (70) formed in the fourth link (72); and the fourth link (72) operatively is connected to a tripping member (74) which itself operatively is associated with the wrapper means and which is movable toward and away from a tripping position. A round baler (10) according to claim 8, characterized in that the tripping member (74) is slidable toward and away from said tripping position and comprises a finger (84) adjacent one end and a hook (86) adjacent the other end thereof; said finger (84) being disposed to engage the drive to the wrapper means when the tripping member (74) is in its tripping position and said hook (86) having a leg (87) extending underneath a flange (102) of a support (104) on the main frame (12) to guide the movement of the tripping member (74). A round baler (10) according to claim 9, characterized in that the tripping member (74) further also comprises an elongated slot (92) for receiving stop means (94) attached to the support (104) in order to limit the movement of said tripping member (74) toward and away from said tripping position.

Inventors: MARGERUM EDWIN O, MERRITT JOHN H, MARGERUM, EDWIN O., MERRITT, JOHN H.
Applicants: FORD NEW HOLLAND NV, NEW HOLLAND BELGIUM N.V.
Application year: 1991
Main classification: A01F15
IPC codes: A01F15