Machine for forming wire arches, and installing the ends of the arches in the ground

A machine bends pieces of wire into an arch configuration, and then inserts the ends of the arch into the ground to form a support for a shelter film protecting a row of plants. An orbital system rotating on an axis parallel to the axis of ground wheels permits the arches to be inserted at close to zero speed relative to ground as the machine moves. The preferred form of the machine installs the film over the arches.

BACKGROUND OF THE INVENTION 
A comparatively recent agricultural technique for growing row plants 
involves the installation of a tent-like tunnel of transparent film over 
the planted rows to provide shelter for the growing plants. The film has 
usually been supported by wire arches bent to shape and installed by hand 
at selected spacing along the rows. The initially straight (or possibly 
somewhat curved from prior use) pieces of wire have usually been carried 
in some makeshift manner, and the wire bent into the arch just prior to 
poking the ends into the ground. This has been done either by one man; or 
by two men. In the latter case, one is positioned at each end of the wire 
as they walk along abreast. The manual labor in the transporting, bending 
and installation of these wire arches has been a limiting factor on the 
use of the system. 
SUMMARY OF THE INVENTION 
A machine embodying the present invention is preferably built as an 
attachment to a standard farm tractor, and has ground wheels that position 
the mechanism and provide the necessary power to operate it as the tractor 
moves forward. Wire pieces are held in storage position, and are fed 
individually to the machine by an operator riding on top of it. The pieces 
are temporarily supported in a position to be engaged by opposite orbital 
bending and clamping devices that establish and maintain the arch 
configuration in a vertical plane. In the course of generating the 
clamping action, the wire pieces are bent over abutments by a 
cam-controlled arm that releases the arches after they are installed. The 
orbital motion causes the arches to be inserted into the ground in a 
rearward movement with respect to the vehicle that is about equal and 
opposite to the forward ground speed.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring particularly to FIGS. 1 and 5, the illustrated machine has a very 
simple frame structure composed of steel bars and tubes held together with 
"U"-bolts. The side bars 10 and 11 are welded respectively to the brackets 
12 and 13, which are essentially channels with notches in the 
forward-facing flanges for receiving a corner of the square steel tube 14 
forming the front transverse member of the frame. The tube 14 is secured 
by the U-bolts 15 and 16, and is the member to which a coupling assembly 
(not shown) will be secured for mounting the illustrated machine on a 
conventional farm tractor. At the rear of the main frame, the square tube 
17 forms the transverse member, and is secured in position by U-bolts as 
shown at 18 in FIG. 5. Brackets as shown at 19 and 20 (in FIGS. 1 and 5, 
respectively) are bolted or welded to the transverse tube 17, and form the 
securing points for the trailing beams 21 and 22 that support the 
components of the film-depositing system. The rear extremities of these 
are interconnected by the transverse bar 23 carried in receptacles as 
shown at 24 for slideable lateral adjustment. This adjustment may be 
secured by set screws (not shown) or cross-bolts. 
An operator's seat 25 is supported on the horizontal leg of the L-shaped 
arm 26, the vertical portion of which is bolted or clamped to the 
transverse member 17. A second L-shaped member shown at 27 in FIG. 5 has 
its vertical portion bolted or clamped to the transverse member 17, with 
the horizontal portion supporting the pan 28 forming the operator's 
footrest. Opposite side diagonals as shown at 29 in FIG. 5, together with 
the upwardly-inclined portion 30 of the pan, confine the operator's feet 
so that they do not accidentally become involved with the moving 
components of the machine. 
A pair of short vertical bars 31 and 32 are secured to opposite sides of 
the frame members 10 and 11, respectively, by clamping plates as shown at 
33 secured by pairs of U-bolts 34. These short vertical bars support the 
stub shafts 35 and 36, which are welded in position. The stub shafts carry 
the rotatable sleeves 37 and 38 secured to hub assemblies for the wheels 
shown at 39 and 40. Adjustable collars as shown at 41 and 42 are 
preferably used for maintaining the lateral position of the wheels with 
respect to the structure of the machine. The power required to operate the 
working components of the machine is derived from the sprocket 43 welded 
to the sleeve 37 associated with the wheel 39. Referring to FIG. 5, the 
flange 44 is also welded to the sleeve 37, and this flange is bolted to 
the central web of the wheel 39 in the usual manner. The opposite wheel 40 
is similarly secured to the sleeve 38, but is not responsible for any of 
the power transfer. The chain 45 transfers power from the sprocket 43 to 
the sprocket 46 secured to the transverse shaft 47 rotatably carried in 
the bearings 48 and 49 respectively mounted on the bars 10 and 11 of the 
main frame. 
The shaft 47 carries the principal operating components of the machine. The 
sleeves 50 and 51 are adjustably secured with respect to the shaft 47 by 
the set screws 52 and 53. The inner radial arm sections 54 and 55 are 
respectively welded to the sleeves 50 and 51, and the set screws 52 and 53 
permit the arm sections 54 and 55 to be placed in a coplanar relationship 
that is properly interrelated with the bending and clamping mechanism 
responsible for forming and installing the wire arches. These components 
are carried by the outer radius arms sections 56 and 57 secured to the 
inner sections by bolts as shown at 58 and 59 (referring to FIGS. 2, 3, 
and 4). These sections of the machine are generally indicated at 60 and 
61, and are shown in greater detail in FIGS. 6, 7, and 8. 
The sprockets 62 and 63 are firmly secured to the frame bars 10 and 11, and 
engage the chains 64 and 65. The sprockets 66 and 67 also engage these 
chains, respectively, and are pinned as shown at 68 in FIG. 7 to the short 
planetary shafts 69. This relationship results in a planetary movement of 
the shafts 69 with respect to the shaft 47. The construction of the 
mechanisms indicated at 60 and 61 are the same, except for a right-left 
relationship. The shafts are carried by the bearings 70 secured to the 
outer extremities of the outer radius arm sections 56 and 57, 
respectively. The transverse fulcrum sections 70a are secured to the inner 
ends of the shafts 69, and rotatively carry the clamping shafts 71. Radial 
clamping arms 72 are secured to the forward ends of these shafts 71, and 
carry the clamping jaws 73. These arms also carry the brackets 74 
providing for the rotatable mounting of the cam follower rollers 75. These 
rollers cooperate with cam plates 76 carried on arms 77 secured to the 
sleeves 78 adjustably secured with respect to the bearings 70 by the set 
screws 79 and 80. This adjustment permits the interaction of the rollers 
75 and the cams 76 to take place at a selected position of the arms 57. 
The pivotal movement of the clamping arms 72 induced by the rollers 75 is 
opposed by the action of the biasing springs 81 (refer to FIG. 8) 
connected to the arm 82 secured to the shafts 71. The opposite ends of the 
springs 81 are connected to the front-rear flanges of the holding arms 
formed by the angle members 83 welded to the fulcrum sections 70a. The 
opposite legs of these angles support the blocks 84, which are secured 
with the screws 85 and 86. The left-hand extremity of this block, as 
viewed in FIG. 6, cooperates with the jaw 73 on the clamping arm to grasp 
the wire work piece 87 firmly to permit the machine to thrust the arch 
into the ground. In the process of clamping the wire against the block 84, 
the wire is first bent around the adjustable abutment 88 secured to the 
angle member 83 with the bolt 89 within a range of adjustment provided by 
the slot 90. 
On opposite sides of the machine, vertical channels as shown at 91 in FIG. 
5 are welded to the side bars 10 and 11 of the frame. These channels form 
the supporting structure for the wire-storage rack generally indicated at 
92, and for the guideway conducting the individual wire work pieces from 
storage to a position where they are picked up by the mechanism shown in 
FIGS. 6, 7, and 8. L-shaped side plates as shown at 93 are welded to the 
channels 91 to form stops for positioning the wire work pieces laterally 
as they rest upon the horizontal leg 94 of the bars 95. The rear 
extremities of these bars are turned upward as shown at 95a to form a stop 
limiting the rearward movement of the wires. The wires are shown in 
storage position in FIG. 1 at 96. Spaced horizontal bars as shown at 97 
and 98 in FIG. 1 are welded to the plates 93. Vertical bars 99 are welded 
to the inner extremities of the front bars 98, and shorter bars 100 are 
welded to the inner ends of the bars 97, along with the vertical legs 101 
of the bars 94. The vertical space between the bars 99, and the 
combination of the bars 100 and the vertical legs 101, forms a vertical 
guideway for conducting the wire work pieces downward to the projecting 
rods 102, where the wires rest until they are picked off by the operating 
components of the machine. 
The sequence of operations is best illustrated in FIGS. 2, 3, and 4. In 
FIG. 2, an operator has pushed a piece of wire 87 out of storage position, 
from which it is dropped down to the projecting rods 102, which support 
the wire at a level just high enough for the abutments 88 to move 
underneath. The wire is then engaged by the front face of the members 83. 
At that instant the bending and clamping action begins. Since the cam 
plates 76 move in fixed relationship with the radius arms 54-56 and 55-57, 
they are rotatably positioned by appropriate adjustment about the bearings 
70, which is maintained by the set screws 79 and 80, such that the cam 
plates engage the rollers 75 at about the instant the wire pieces 87 are 
engaged by the faces of the members 83. The action of the cams 76 induces 
a counterclockwise rotation, of the clamping arms 72, as viewed in FIG. 6, 
bringing the clamping jaws 73 downward into engagement with the wire. The 
jaws 73 have a V-shaped configuration, as shown best in FIG. 8, causing 
the wire to be centered in the central portion of the jaw as the wire is 
engaged and bent downward about the abutments 88. This condition is 
illustrated in FIG. 3. During this movement, the effect of the chains 64 
and 65, which associate sprockets of the same size, is to maintain the 
front face of the members 83 close to a vertical plane throughout this 
orbital movement. As the rotation of the clamping arms continues, the jaws 
finally shove the wires against the fixed clamping jaws so that pressure 
is exerted between the moving jaws 73 and the edges 103 of the blocks 84 
(see FIG. 6). As full pressure against the wire develops, the wire is 
preferably lifted off of the abutments 88. Whether or not this takes 
place, the resulting arch configuration of the wire is easily thrust into 
the ground as shown in FIG. 4. The thrusting of the wire ends into the 
ground necessitates that the action take place at close to zero relative 
ground speed to avoid distorting the wire, or tipping it out of position 
in the ground. This relationship is maintained by a selection of the 
ratios between the sprockets 43 and 46 such that the length of the radius 
arms, as they rotate about the axis of the shaft 47, produces a rearward 
velocity at the clamping mechanism equal to the forward velocity of the 
ground wheels. This relationship, of course, exists only at the downward 
portion of the rotation of the radius arms. During this period, the 
movement of the cam plates 76 releases the rollers 75, and the clamping 
arms 72 spring free of the wires under the action of the springs 81. The 
continued rearward rotation of the radius arms moves the clamping 
mechanism back and away from the installed wire. While the movement of the 
clamping mechanisms approaches zero ground speed, it is preferable that 
there be a slight rearward velocity sufficient to assure clearance from 
the wire as the radius arms continue with their rearward position. The 
abutments 88 must be swung back to clear the installed wire. Where the 
wire has been lifted well off the abutments 88 in the clamping process, 
this is less critical, as more clearance is present. The clamping 
mechanisms will be raised as the radius arms continue to rotate rearwardly 
and upwardly to the point where the installed wire is easily cleared. The 
arms then continue their rotation to where they can intercept and 
manipulate the next wire that will have been dropped down into position. 
During this rotary movement, the radius arms and clamping mechanisms move 
through the space between the bars 99 and 100, and the plates 93. 
Applicant's experience with this type of farm machinery has established 
that it is occasionally necessary to make allowances for the effect of 
wear upon chain drive systems of this type. To avoid the development of 
objectionable lost motion, the tension spring 104 (refer to FIG. 5) has 
been added to the mechanism. This spring extends from the short crank arm 
105 fixed with respect to the shaft 47 and the eyebolt 106 engaging the 
tab 107 of the bracket 108 secured to the side bar 10 of the frame. The 
eyebolt is adjustable to control the tension of the spring, the effect 
being to eliminate the lost motion during the active portion of the 
rotation of the radius arms. The spring 104 and its associated components 
are optional. In the presence of some degree of lost motion, the position 
of the crank arm 105 can be selected such as to produce a snap-back action 
tending to improve the release of the clamping mechanism from the 
installed wires. This will occur if the spring 104 passes over-center with 
respect to the axis of the shaft 47 at the time of the release of the 
wires from the clamping mechanisms. 
Experience in the operation of this machine has established that 
reliability and freedom from malfunction are improved by providing 
resilient retaining flaps for releaseably retaining the wire while its 
rests on the projecting rods 102. These are shown at 109 in FIG. 1, and 
are essentially strips of heavy fabric secured to the lower extremity of 
the members 99, which are above the path of movement of the clamping 
mechanisms. It has also been established that the presence of the 
resilient flaps 110, which are secured to the similarly positioned plates 
111 welded to the members 98, improves the behavior of the wires during 
the manipulation by the clamping mechanisms. These flaps are positioned to 
engage the wires during the forward and downward movement while they are 
in the grasp of the clamping mechanisms, and tend to prevent a whipping 
action which interferes with accurate placement. 
It is preferable to combine the machine described above with a system for 
laying out a sheet of plastic film over the arches that have been 
installed. This mechanism can be of a conventional type, and forms no part 
of the present invention. For purposes of convenience, however, the 
combination of these two mechanical systems produces a very compact and 
economical machine. The film-laying system is shown best in FIG. 9, which 
should be viewed in conjunction with FIG. 1. The furrow-opening discs 112 
and 113 are mounted in the usual fashion on the struts 114 and 115 secured 
to the frame side members 10 and 11 with clamps (not shown) so that they 
are adjustable vertically. These discs open furrows in positions to 
receive the edges 116 and 117 of a sheet of plastic film as it is pulled 
off from the roll 118. The roll has a tubular core, and is held in 
position by the spindles 119 and 120 carried by the ends of the arms 121 
and 122 provided with cylindrical sleeves 123 and 124 mounted for rotative 
and axial adjustment on the spindles 125 and 126 secured to the brackets 
19 and 19a. The set screws 127 and 128 lock the sleeves and arms in a 
selected position to establish the corresponding position of the roll 118. 
Referring to FIG. 1, the wheels 129 and 130 mounted on the struts 129a and 
130a depress the edges of the plastic into the furrows opened by the discs 
112 and 113. The placement of the wheels 129 and 130 is controlled by the 
clamping brackets 131 and 132 embracing the trailing beams 21 and 22. The 
second set of discs 133 and 134 is similarly mounted behind the wheels to 
force the ridge of dirt established by the opening discs 112 and 113 back 
into the furrow to anchor the edges of the plastic material in place. This 
completes a tunnel-like enclosure over the tops of the row of plants. 
This compact machine efficiently performs a single-pass operation forming 
and installing the arches, and applying the plastic covering over them. 
All this is accomplished with a single operator (in addition to the 
operator driving this tractor) with a minimum demand of skill and training 
on this operator. Experience with the machine has established that it is 
capable of handling pieces of wire that have been used previously, and 
which have a small degree of curvature in them as a result of having been 
formed into the arch configuration in an earlier installation. There is a 
limit to the extent of the curvature that can be accommodated by the 
machine, however, and attention should be given to providing wire pieces 
that are not sufficiently curved to interfere with the engagement of the 
clamping devices, and their subsequent manipulation. For example, a piece 
of wire suspended on the projecting rods 102 should not have sufficient 
curvature that it will assume a position underneath the abutments 88 on 
the clamping devices, and would therefore not be properly picked up. An 
excessive degree of curvature also could conceivably interfere with the 
engagement of the clamping jaws, if the excessively curved rods were 
rotated somewhat about a horizontal axis as they were held by the machine. 
The exact degree of curvature of the rods that the machine will tolerate 
can only be controlled by experiment with the particular machine involved. 
If necessary, a simple straightening operation can restore the rods to a 
condition that the machine can accommodate.