Method of manufacturing a reinforcing cage for a concrete post, and a fixture for carrying out the method

In a method of manufacturing a reinforcing unit in the form of a cage or basket for a concrete post, the reinforcing rods are placed on pivotable, concave support arms in a fixture so as to form two separate concave parts of the finished unit. Support rings are then secured along said parts perpendicularly to the axis of the finished unit. The parts are brought together, and the support rings of one part are joined to the reinforcing rods of a corresponding part. The said parts are preferably brought together by swinging the support arms upwards in a manner such that the axis of the cage falls in a vertical longitudinal medium plane through the fixture. The support arms are pivoted downwards, whereupon a helical reinforcing element is threaded onto the unit from one end thereof and joined thereto. In this method use is made of a plurality of fixture units each comprising a frame, and two concave support arms pivotally arranged around horizontal shafts.

When manufacturing reinforcing units in the form of cages or baskets for 
reinforcing concrete posts, which reinforcing units comprise rectalinear 
rods held by encircling supports, closed supports are, for example, 
suspended on hangers and the reinforcing rods inserted in and tied 
securely to the supports. One method has been to attach open supports on 
suspended reinforcing rods. Another method is one in which the reinforcing 
unit is assembled on a table or on the floor by successive rolling of the 
reinforcing unit. 
All of these methods are time consuming, particularly in the case of 
manufacturing reinforcing cages for long concrete posts, and do not 
provide for accuracy in the finished reinforcing cage, which cannot be 
accepted in the case of concrete posts having a thin wall, when seen in 
cross section. 
The described methods also render access difficult, particularly in the 
case of long and narrow units, particularly when the reinforcing rods are 
positioned close together. Thus, the manufacture of such a reinforcing 
unit takes considerable time, which results in high costs. 
The present invention provides a considerably simpler method of 
manufacturing reinforcing units in the form of cages or baskets of the 
aforementioned type. 
The invention is characterized in that reinforcing rods are placed on 
pivotable, concave support arms in a fixture, in a manner such that the 
rods form two separate concave parts which together form the reinforcing 
cage; that support rings are secured along said parts perpendicularly to 
the axis of the finished reinforcing cage; that the parts are brought 
together; and that the support rings of one part are joined with the 
reinforcing rods of the opposite part. 
When applying the method of the invention it is preferred that the parts 
comprise halves of the finished cage, and that the support rings are 
arranged alternately at approximately equal distances in the two halves. 
By arranging the reinforcing rods in the aforementioned manner, in the form 
of two parts (halves), ready access can be had during the reinforcing 
work. In this way the work of the workman is greatly facilitated. 
Furthermore, the ease of access enables the rods to be better secured. 
The arrangement of the support rings provides a more stable reinforcing 
cage. Since the reinforcing rods can be fixed in position in the concave 
support arms, the greatest possible accuracy is obtained with respect to 
the position of said rods, thereby providing an accurately produced 
reinforcing cage. The division of the cage into two parts or halves also 
affords the advantage whereby the reinforcing rods can be readily placed 
in the centre of the fixture where they are easily accessible, said rods 
being either lifted or drawn horizontally into said centre. Thus, the rod 
can be moved through a short distance to their respective positions in the 
concave support arms without causing heavy work. 
Moreover, since rods of different dimension and length are used in one and 
the same reinforcing unit, the correct rod can more readily be arranged in 
the correct place, e.g. by giving a specific rod and its intended position 
in the fixture the same colour marking. 
In a preferred embodiment of the invention the parts of the cage are joined 
together by swinging the support arms upwardly in a manner such that the 
axis of the reinforcing cage lies in a vertical, longitudinal mean plane 
through the fixture. 
Alternatively, only the support arms for one part of the basket may be 
pivotable, said one part being arranged to be pivoted through 
approximately 180.degree. into position on the other part. In this case, 
however, high requirements are placed on the attachment of the reinforcing 
rods to the support arms. Further, such a method results in difficulties 
when a helical reinforcing element is later placed on the reinforcing 
cage. 
When, as is preferred, both support arms are arranged to be swung up 
towards each other, joining of the two parts together is greatly 
facilitated. Preferably the two parts are tied together. The two parts 
(halves) are readily accessible in the aforementioned upwardly swung 
position. 
When carrying out the method, it is preferred that the reinforcing cage is 
supported by vertically movable support means associated with the fixture 
and arranged in spaced apart relationship, said support means being 
lowered one at a time out of engagement with the reinforcing cage when the 
helical reinforcing element is threaded thereonto. 
The work involved with applying the helical reinforcing element and its 
tying to the cage, which work is extraordinarily complicated when applying 
previously known methods, can, in this way, be greatly assisted and 
simplified. 
The invention also relates to a fixture comprising a plurality of spaced 
apart units for carrying out the aforementioned method. 
A fixture unit is substantially characterized by a frame, two concave 
support arms which are pivotable about parallel, horizontal shafts; means 
located in the arms, e.g. recesses, for receiving reinforcing rods; means 
for fixing the arms extending in opposite directions in a substantially 
horizontal position; and means for fixing the arms when these are brought 
together in a preferably substantially vertical position. 
A plurality of such units sequentially arranged in spaced apart 
relationship results in a fixture of low cost, thereby affording the 
aforementioned advantages. The manufacture of the reinforcing cage having 
a length of 20 to 25 meters, which when applying conventional 
manufacturing methods can be expected to take about 20 man hours, will 
only take about 4 to 5 man hours when using a fixture according to the 
invention. In addition to this substantial saving in cost, there is also 
obtained the aforementioned increase in precision of the finished 
reinforcing cage. 
In practice it is preferred that the support arms are replaceably arranged 
in the frame, so that said arms can be replaced by arms of different 
shapes and form. 
In this way, reinforcing cages of different types and shapes can be 
manufactured by means of one and the same fixture. It is thus possible, 
for example, to manufacture conically tapering reinforcing cages, the 
adjecently lying fixture units exhibiting a concave shape with a radius of 
curvature which decreses axially. Alternatively, all fixture units can 
carry identical support arms for manufacturing cylindrical reinforcing 
cages for concrete posts with corresponding profile design. Other types of 
reinforcing cages can also be manufactured, depending upon the design of 
the support arms. 
In order to render the task of placing the helical reinforcing element in 
position more easy, it is preferred that the support arms can be swung 
downwardly to a vertically downwardly extended position. In this way, the 
support arms can be moved out of the way so as not to present an obstacle 
to the threading of the helical reinforcing element. 
Conveniently the frame also has a centrally arranged support means for the 
reinforcing rods and for the reinforcing cage, respectively. These support 
means are suitably movable in a vertical direction and actuated by a 
cylinder-piston arrangement. 
In a preferred embodiment, the support means comprises rollers having 
horizontal shafts. Such rollers facilitate the positioning of the 
reinforcing rods on the figure, when the work of manufacturing a cage is 
to commence. 
The central support means on the fixture units may suitably comprise a 
cradle or a stirrup-shaped element of concave form, which is located at a 
level above the support means and is removably arranged. 
When the reinforcing rods shall be placed in position, the support means is 
removed and is then later returned to its initial position when the parts 
of the reinforcing cage have been moved together by the support arms, in 
order to support the reinforcing cage. As above mentioned, the support 
arms can then be dropped or swung down to their vertically extending 
position. 
When the helical reinforcing element is then placed in position, the 
support means are lowered one after the other by means of the 
piston-cylinder arrangement, the reinforcing cage being supported by the 
support means on the fixture units located on either side of that unit 
which has been lowered to permit the helical reinforcing element to pass. 
The helical reinforcing element can be progressively threaded on the 
reinforcing rods by lowering the support means one after the other 
beginning from one end of the reinforcing cage, in the aforementioned 
manner. 
In one further embodiment of the fixture units according to the invention, 
those concave support arms of the units which extend in the same direction 
are interconnected, e.g. by rods extending along the underside of the 
arms, and are actuated by a lifting means so that they can be swung up in 
unison by the support arms thus joined to a vertical position. The rods of 
a reinforcing cage having a length of 20 to 25 meters may weigh as much as 
approximately 100 kg, of which weight half is represented by each half 
part of the cage, and it will thus be understood that the work involved is 
made much easier by the fact that the support arms carrying the rod can be 
swung up mechanically.

Thus, the reference 1 identifies one half of a reinforcing cage being 
manufactured in a fixture. The reference numeral 2 identifies the other 
half of the reinforcing cage. The reference 3 identifies the reinforcing 
rods of which the cage comprises, while the reference 4 identifies the 
spaced-apart support rings of respective halves. 
FIG. 1 illustrates how the reinforcing rods 3 are arranged on pivotable, 
concave support arms 14 and 15, respectively, in a manner such as to form 
the two separated, concave parts 1 and 2 of the finished cage. The fixture 
comprises eleven units 10. FIGS. 3 and 4 illustrate how the arms 14 and 15 
of the fixture are swung to a vertical position, the parts 1 and 2 being 
brought together in this position. The support rings 4 of the different 
parts are then tied or lashed to the reinforcing rods of an opposing part. 
The axis of the reinforcing cage is thus located in a vertical, 
longitudinal mean plane through the fixture. 
FIG. 4 illustrates the support arms 14, 15 in their downwardly swung 
position, and FIG. 5 illustrates a helical reinforcing element 5 being 
threaded onto the cage. Subsequent to being placed in position, the 
helical reinforcing element is tied or lashed to the finished cage. 
The reinforcing rods 3 are normally tied or lashed to the support rings 4, 
although in certain instances the rods may be welded to said rings. The 
support ring 4 located at the fixed end of the cage is normally always 
welded to the rods 3. 
FIG. 2 illustrates in larger scale one of the units 10 of the fixture. The 
units 10 comprise the frame 11 having legs 11a and a lower support plate 
11b. Each fixture carries two concave support arms 14 and 15 which are 
pivotable about parallel horizontal shafts 12 and 13, respectively. 
Arranged in uniform spaced relationship in the arms are recesses 14a and 
15a, respectively, for receiving reinforcing rods 3. The arms also carry 
locking means 18. 
In FIG. 2 there is illustrated in broken lines a shaft 13 in a withdrawn 
position, thereby indicating that the support arms 14 and 15 are 
exhangeably arranged, i.e. said arms can be replaced by arms of another 
shape or form in the frame. 
Arranged in the frame is a pneumatic cylinder 20 having a piston 21 which 
carries a box 22 in which there is located a rotatable carrying and 
conveying means for reinforcing rods, said means having the form of a 
rotatable roll 23. The box 22 is joined with a rod 30 which removably 
supports a support means in the form of a concave stirrup-like structure 
or cradle 31 for the reinforcing cage. The stirrup-like structure is 
located at a higher level than the upper part of the roller 23. When the 
roller is to be used, the stirrup-like structure is removed and replaced 
later when it is to be used to support the reinforcing cage. 
The cylinder-piston-arrangement 20, 21 is operated by means of a device 24 
having a handle 25, via feed and return lines 26 and 27, respectively. The 
reference 28 identifies a support line for compressed air, only part of 
the line being shown. 
The unit illustrated in FIG. 2 is also provided with an axially 
displaceable and rotatable handle 35 which co-acts with a half-moon shaped 
recess 14b in the support arm 14 for fixing the same in the horizontal 
position illustrated in FIG. 1. The handle 35 has a peg thereon which, 
when the support arm 14 is lifted up to the vertical position shown in 
FIG. 4, engages a hole in the support arm, thereby to fix the support arm 
in the vertical position. FIG. 4 also illustrates a quick-acting lock for 
holding the two support arms together in their uplifted position. Thus, on 
the support arm 14 there is provided a quick-lock arrangement 14d arranged 
to co-act with a recess 15d on the support arm 15. 
FIG. 4 also illustrates how the support arms 14, 15, after releasing the 
locking arrangement 14d, 15d and the handle 35, 36, can be swung to a 
vertically extending position, as indicated by the chain lines in said 
figure. 
FIG. 5 illustrates how a helical reinforcing element is threaded on the 
cage from the narrow end thereof. The support means 31 on the outer 
fixture unit 10 has been moved downwardly so that the reinforcing cage 
only rests on corresponding support means 31 on adjacent fixture units. 
The helical reinforcing element 5 can in this way be readily threaded on 
the cage. As the helical reinforcing element is moved along the cage, 
successive support means 31 of consecutive fixture units are lowered. 
Subsequent to placing the helical reinforcing element in position and tying 
said element or fixing it in some other way, the reinforcing cage 6 is 
ready for use. 
Instead of the reinforcing rods 3 being held in recesses 14a by the locking 
means 18 located on the support arms 14, when said support arms are swung 
to their upward position, it is possible to provide other types of locking 
means (not shown) arranged to engage the support rings 4 of respective 
parts of the cage and thereby contribute to holding the unit 1 and 2 as a 
whole in the correct position during the upward swinging of said part. 
Furthermore, as before-mentioned, the support arms 14 and 15 of all fixture 
units 10 extending in the same direction can be joined together by a rod 
(not shown) arranged to be actuated by a piston-cylinder-arrangement (not 
shown) simultaneously to swing the support arms extending to the left and 
to the right, respectively, of the two parts 1 and 2 of the cage upwardly.