FR2743381A1 - BANCH FORMWORK EQUIPPED WITH AUTOMATIC BANCH TIGHTENING DEVICE - Google Patents

Abstract

The invention relates to a formwork comprising two shutters (10, 12) arranged substantially parallel to one another and a device for clamping the shutters comprising a tie rod (18, 20) connecting the two shutters (10, 12), the tie rod being immobilized in traction. by a first end on a first panel (10), the second panel (12) comprising means (29) for axially guiding the tie rod (18, 20) in which it is free to slide. The device for clamping the formwork (10, 12) comprises a jack (38) which is arranged substantially transversely to the tie rod (18, 20). This jack comprises on the one hand, a body (39) fixed on the second panel (12) and on the other hand, a movable jack rod (40) provided at its end with a cam surface (10, 12) for actuating the tie rod (18, 20). The tie rod comprises at its second end a cam follower (104C, 106C) adapted to cooperate with said cam (110, 112) in order to cause the clamping of the two forms (10, 12) when the actuator is actuated.

Description

The present invention relates to a metal formwork

  lique used for the construction of walls or other

reinforced concrete structures.

  Such forms are known, of the type comprising two panels arranged substantially parallel to each other and a device for clamping the panels with at least one tie connecting the two panels, the tie being immobilized in tension by a first end on a first form, the second plate having axial guide means of the tie rod in which it is

free to slide.

  In the state of the art, the panels are connected to one another by one or more threaded tie rods extending substantially perpendicular to the panels. These tie rods pass through the banquettes from one end to the other and carry at each end a nut that bears against the outer surface of the banche. In order to proceed with the clamping of the boards, and in particular their approach, the nuts are screwed against the boards, so that the gap between them decreases.

  and that they come against spacers.

  Such an operation is relatively tedious and time consuming. In addition, it requires the presence of an operator at the rear of each section, which makes it difficult to adjust their spacing when the backward movement of at least one side is insufficient for an operator to access it. Moreover, it is common to use a hammer wrench for screwing nuts. This use causes nuisance

sound.

  The invention aims to provide a formwork, which the approximation and clamping of banches can be performed in a simple and convenient by a single operator. For this purpose, the subject of the invention is a formwork of the aforementioned type, characterized in that the clamping device of the panels comprises a jack, which is arranged

  substantially transversely to the tie rod, this jack comprises

  on the one hand, a body fixed on the second side and on the other hand, a movable jack rod provided at its end with a camming surface of the pulling rod,

  which pulling has at its second end a counter

  cam adapted to cooperate with said cam in order to

  cause the two side panels to tighten when actuating

cylinder.

  According to particular embodiments,

  the invention may include one or more of the

  following features: - the counter cam is formed of two coplanar parts arranged on either side of the axis of the

  pulling and the cam surface is in two parts coplanar

  two teeth of a prolonged range

  the rod is positioned between the two teeth of the fork, - the cam follower is carried by a sleeve traversed from one side by the tie rod and the pulling comprises, at its second end, a stop blocking the sleeve,

  - the second form includes a passage through

  tug guide, - the tie rod is a threaded rod, - the first handle has a

  unidirectional blocking of the tie rod in which

  in tension the first end of the tie rod, - the unidirectional locking device comprises two half-nuts delimiting a threaded duct receiving the tie rod and having at their end a frustoconical outer bevel, these two half-nuts

  being received free in a cage whose end wall

  opposite the chamfered end of the two halves

  nuts has a central passage for the tie rod and forms a concave seat conical bearing surface, the locking device further comprising an axial helical spring bearing on said cage and biasing the two half-nuts to the conical seat, the two half-nuts being movable between a locking position in which they form wedge between the seat and the tie when the latter is pulled out of the device, and a release position in which they are released from the seat and the tie when the latter is pushed in the device, the formwork comprises a pair of rods arranged substantially parallel and connecting the two panels, each tie being immobilized in tension at one end on the first side, the second side having axial guide means of each

  in which each tie rod is free to slide

  ser, and the cylinder is a double-rod cylinder, each rod is provided at its end with a cam surface adapted to cooperate with a counter-cam carried by a corresponding tie rod,

  - The cylinder is a hydraulic cylinder.

  The invention will be better understood when reading

  the following description, given solely for the purpose of

  example, and made with reference to the drawings on-

  which: - Figure 1 is a cross-sectional view

  of a formwork according to the invention, before adjustment of the

  banches; - Figure 2 is a longitudinal sectional view of a unidirectional locking device used in the composition of the formwork of Figure 1; - Figure 3 is a partial sectional view taken along the line III-III of Figure 1; FIGS. 4 and 5 are views similar to

  shown in Figure 2, represented at different stages

  operating conditions; - Figure 6 is a view similar to that of Figure 1, after adjustment of the spacing banches; and - Figure 7 is a partial sectional view

  taken along line VII-VII of Figure 6.

  The formwork shown in Figure 1 comprises two panels 10, 12, arranged vertically, face to face and substantially parallel to each other. Each banche comprises a parallelepiped frame 14 closed on one side

  by a panel 16 defining a formwork surface.

  The panels are interconnected by a device for approximation and clamping comprising two pairs of tie rods arranged two by two in two planes

  vertical parallels. In the figures, only two

  rants, denoted respectively 18 and 20, are represented.

  They are contained in the same vertical plane P (plane of FIGS. 1 and 6) perpendicular to the form surfaces

  16. These tie rods are formed by threaded rods.

  In its upper part, the first wall 10 comprises a support 22 in which is fixed a device 24 for unidirectional blocking of the tie rod 18.

  will be described in detail with reference to FIGS. 2, 4 and 5.

  In its upper part, the second wall 12 also includes a support 26, in which is incorporated a device 28 for pulling the tie rod 18. The device 28 is disposed behind a guide passage 29 of the

  pulling in which the latter is free to slide.

  The devices 24 and 28 are arranged

  at the same height, so that the tie rod 18 extends

substantially horizontally.

  The tie rod 20 is arranged in the lower part

  formwork. It crosses the formwork walls 16

  following guide passages 30, 32 behind the

  which are welded reinforcement angles 30A, 32A. The

  pulling is immobilized in traction at a first end.

  The locking device 34 is for example welded to the frame 14 of the first form. The second end of the tie rod 20 is engaged in a traction device 36, similar to the device 28 and

worn by the second block 12.

  A double rod hydraulic cylinder 38 is integrated in the second box 12 to actuate the traction devices 28 and 36. It is controlled by a hydraulic hand pump not shown. The axis of this cylinder extends in the plane P defined by the tie rods 18 and 20 and

  is disposed substantially perpendicular to the tie rods.

  The body of the jack 39 is fixed to the structure of the form

  12, while the actuating rods, noted respectively

  40 and 42, are directed upwards and downwards to simultaneously activate the

  traction 28 and 36. This jack allows the simultaneous movement

  tane of the two actuating rods 40, 42 in opposite directions. FIG. 2 shows the device 24 for unidirectionally locking the tie rod 18. The device 34

is identical.

  Such a device comprises a cylindrical cage open at its two ends in which are received two half-nuts 52, 54 free and a coil spring 56.

  The cage 50 comprises a tube 58 closed at its first

  first end by a sleeve 60 and at its second end

  mity by a crown 62 forming bottom.

  The sleeve 60 comprises an axial passage 64 for guiding the tie rod 18. It has on its inner face a conical bearing surface 66 bordering the passage 64. It thus forms a concave locking seat for both

half-nuts 52,54.

  These two half-nuts are identical. They are each formed of a demimanchon, cut along a longitudinal plane. The two associated half-nuts delimit an axial duct 68 for receiving the tie rod 18.

is tapped over its entire length.

  Each half-nut has two successive sections 70, 72 of substantially equal length and different thickness. The section 70, oriented towards the seat 60 has an outer allowance 74. It presents to

  its end facing the seat 60, a truncated chamfer

  outer ring 76, the apex angle of which is

  equal to that of the bearing surface 66. At this same end, the axial duct 68 is flared by a chamfer

inside 78.

  The opposite end of the overthickness 74 delimits

  mite an annular bearing front 80 for the spring 56.

  A groove 82 with an inclined side wall is furthermore

  arranged externally on section 72.

  As shown in Figure 2, the spring 56 surrounds the section 72. It is compressed between the front

  80 and the ring 62 and requests the two halves

  nuts 52, 54 against the bearing surface 66. The half

  nuts thus form wedge between the seat 60 and the tie 18, ensuring the immobilization in traction of the latter. In Figure 3 is shown in detail the pulling device 28 of Figure 1. This device

  comprises a sleeve 100 traversed by a cylindrical duct

  102 which smooth wall diameter slightly greater than that of the tie rod 18. This sleeve has in its outer side wall two grooves 104, 106 symmetrical with respect to the plane P. The grooves 104, 106 are delimited by

  flat bottoms 104A, 106A and two banks two to two coplanar

  ners. A first edge 104B, 106B (Figure 1) extends perpendicularly to the axis of the sleeve, while the other side 104C, 106C defines with it a non-zero angle. These two banks 104C, 106C form a counter cam in two parts inclined about 30 relative to the axis of the cylinder. The two parts 104C, 106C of the counter-cam are

  adapted to cooperate with a corresponding cam surface

  in two parts 110,112 carried at the end of teeth 114, 116 of a fork 118 extending axially

the cylinder rod 40.

  The distance between the teeth 114, 116 is substantially equal to the distance separating the funds 104A, 106A, the teeth thus being partially received in the grooves 104, 106. The two parts 110, 112 of the cam surface are coplanar and are inclined by relative to the cylinder axis of the same angle as the banks 104C, 106C delimiting

the counter-cam.

  The sleeve 100 and the fork 118 are protected

  two lateral walls 120, 122 of the support 26 and a front closure wall 124, in which is formed the passage 29 for guiding the tie 18. This passage

  is extended by an overlay 126 guiding in transla-

  The rear wall 127 of the support 26 has a complementary coaxial passage 128 ensuring

  also the translational guidance of the sleeve 100.

  The traction device 28 further comprises a locking nut 130 associated with a counter nut 132 screwed

  at the end of the tie rod 18 beyond the sleeve 100.

  The nut and the locknut form a blocking stop

of the sleeve on the tie 18.

  The pulling device 36 is similar to the device 28, the fork extending the cylinder rod 42. However, the device 36 is mounted returned from

  relative to the axis of the tie rod.

  In order to have the formwork for casting, it is deposited, for example using a crane, the two panels face to face. An operator then introduces the tie rods 18 and 20 from the rear of the second panel 12 through the sleeves 100. Tubular spacers 134, 136 are then interposed between the panels at the passages of the tie rods. These spacers have lengths corresponding to the desired interval between the branches. The operator then pushes the tie rods 18, 20, through the spacers until their first ends enter the passages 64 of the devices.

unidirectional blocking.

  As shown in Figure 4, explain

  citing the operation of the device 24, the end of the tie rod 18, inserted in the direction of the arrow F1, pushes the two half-nuts 52, 54 towards the ring gear 62

  against the action of the jurisdiction 56. The two half-

  nuts then deviate in the direction of the arrows F2, F3. The inner edge of the crown 62 is then received

in the throat 82.

  The spacing of the half-nuts allows the passage of the tie rod 18, as shown in FIG. 5. The tie rod can thus be put in place, without it being necessary.

  screw it in the two half-nuts.

  The tie rod is depressed until the nuts, 132, previously arranged at the other end of the

  pulling contact the sleeve 100.

  When the tie is released, both halves

  nuts 52, 54 are tightened in the direction of the arrows F4, F5 (Figure 2) around the tie under the action of the spring 56. The guide of the two half-nuts is provided by the conical surface 66 of the seat 60 and by the walls

  inclined groove 82 cooperating with the ring 62.

  The release of the tie rod 18 leads to the state shown in FIG. 2, in which the two half-nuts form a wedge between the seat 60 and the tie rod 18, and thus ensure the pulling of the tie rod in the direction of the arrow F6. . The tie rod 20 is mounted and immobilized in a similar manner. In order to reconcile and tighten

  both sides, the operator actuates the hydraulic cylinder

  than two rods, using the hand pump, in order to

  cause the simultaneous output of the cylinder rods.

  It is then understood that in each traction device 28, 36, the fork 118 acts on the counter-cam 104C, 106C forming a reaction, via the

  two-piece cam surface 110, 112. During the movement

  vertical direction of the fork 118, the sleeve 100 moves horizontally relative to the wall 12 and rests against the nut 130 screwed on the tie rod. The latter being immobilized, at its other end, in the locking device, the sleeve 100, blocked by the nut, can not move relative to the ground, so that the second wall 12 approaches the first board by sliding from one or other of the banches on the ground. The simultaneous action of the upper traction devices 28 and lower 36 ensures a rapprochement of

  two banches which remain continually parallel.

  When the desired gap between the two banks is

  reached, as shown in Figure 6, the struc-

  134, 136 are in contact respectively with the

  front walls of the supports 22, 26 and the

  16. They are thus kept tight at a distance.

  determined by the length of the spacers.

  In this situation, as shown in FIG. 7, the fork 118 of the traction device completely encloses the sleeve 100. The sleeve is then partially out of the over-bale 126

ensuring its guidance.

  After the casting of the structure and sufficient curing of the concrete, the nuts 130 and the lock nuts

  132 are removed to release the tie rods. These last

  then removed from the unscrewing blocking devices. In the state shown in Figure 2, the tie rod 18 may in fact be unscrewed by rotation, the two half-nuts 52, 54 defining together a conduit internally provided with a thread complementary to that of the thread of the tie rod 18. so separated are

then removed.

  After dismounting the tie rods, it is advisable to

  retract the cylinder for later use.

  Such an arrangement allows easy adjustment of the spacing of the panels without the need for an operator to be placed behind one of the panels while

the approximation and the tightening.

  In addition, it allows a mounting of the tie rods by a

  operator alone placed behind the second block 12.

  In fact, the locking of the tie rods is effected automatically

  only in the unidirectional locking devices 24, 34. Moreover, the disassembly thereof is carried out by a simple manual unscrewing from the back of the

second round 12.

Claims (9)

  1.- formwork of the type comprising two panels (10, 12) disposed substantially parallel to each other and a clamping device of the panels having at least one tie rod (18, 20) connecting the two panels (10, 12), the   pulling being immobilized in traction by a first ex-   tremity on a first side (10), the second side (12) having means (29) for axial guidance of the tie rod (18,20) in which it is free to slide,   characterized in that the clamping device of the   (10, 12) comprises a jack (38) which is disposed substantially   transversely to the tie rod (18, 20), this jack comprising on the one hand, a body (39) fixed on the second wall (12) and, on the other hand, a movable jack rod (40) provided at its end with an actuating cam surface (110, 112) of the tie rod (18, 20), which pulling comprises at its second end a cam follower (104C, 106C) adapted to cooperate with said cam (110, 112) in order to to cause the tightening of the two panels (10, 12) when actuating the cylinder.   2. Formwork according to claim 1, characterized   in that the cam follower is formed of two coplanar portions (104C, 106C) disposed on either side of the axis of the tie rod and in that the cam surface is in two coplanar portions (110, 112) carried by two teeth (114,116) of a fork (118) extending the cylinder rod (40), the tie rod being disposed between the two teeth of the fork.   3. Formwork according to claim 1 or 2, characterized in that the cam follower (104C, 106C) is carried by a sleeve (100) traversed from one side by the tie rod (18, 20) and the tie comprises, at his second   end, a stop (130, 132) for locking the sleeve.   4. Formwork according to any one of the   cations, characterized in that the second wall (12) has a passage (29,32) passing through guide of the tie rod (18,20).   5. Formwork according to any one of the   prior art, characterized in that the tie rod (18, 20) is a threaded rod.   6. Formwork according to any one of the   cations, characterized in that the first panel (10) comprises a device (24, 34) for unidirectionally locking the tie rod (18, 20) in which is   immobilized in tension the first end of the tie rod.   7. Formwork according to claims 5 and 6   taken together, characterized in that the unidirectional locking device (24, 34) comprises two half-nuts (52, 54) delimiting a threaded duct (68) for receiving the tie rod (18, 20) and having at their end a   outer frustoconical chamfer (76), these two half   nuts being received free in a cage (50) whose end wall facing the chamfered end of the two half-nuts (52, 54) has a central passage (64) for the tie rod (18, 20) and forms a concave seat with conical bearing surface (66), the locking device further comprising an axial coil spring (56) bearing on said cage (50) and biasing the two half-nuts (52, 54) towards the seat conical (60), the two half-nuts (52, 54) being movable between a locking position in which they form wedge between the seat (60) and the tie rod (18, 20) when the latter   is pulled out of the device, and a release position   in which they are released from the seat (60) and the   pulling (18) when the latter is pushed into the operative part.   8. Formwork according to any one of the   previous types, of the type comprising at least one   pair of tie rods (18, 20) arranged substantially parallel   and connecting the two panels (10, 12), each tie (18, 20) being immobilized in traction at a first end on the first wall (10), the second wall (12) having means (29, 32) of axial guidance of each tie rod (18,20) in which each tie rod is free to slide, characterized in that the jack (38) is a double-rod cylinder (40,42), each rod of which is provided at its end with a cam surface (110,112) adapted to cooperate with a cam follower   (104C, 106C) carried by a corresponding tie rod.   9. Formwork according to any one of the   cations, characterized in that the jack is a hydraulic cylinder.