The invention relates to an apparatus for bending rattan stems or blanks of other material which when subjected to heat, chemical or mechanical processes become soft and pliable, but which regain their original hardness and strengt by drying or another reaction, the apparatus consisting of a table or the like which is provided with guide sheaves and a bending template which presses the blank against abutment means with the aid of a pressure cylinder or the like.

From US Patents 1.019.472 and 2.418.100, apparatus are known for bending wood and plywood, but these apparatus have a very limited area of utilization and do not satisfy today's requirements for efficient production.

The previously known inventions are limited to bending in one plane, and are cumbersome to readjust if the blanks are to be given different configurations.

The object of the invention is to enable the bending of rattan stems {or other material) in all planes in one operation, and to permit the removal of the shaped rattan rod from the bending apparatus immediately so that efficient production is obtained.

The object of the invention is achieved by means of an apparatus of the type recited above which is characterized in that each guide sheave is arranged in conjunction with a rotary actuator and a bending sheave, the axis of the guide sheaves lying on an extension of the shaft of the rotary actuator, and each rotary actuator is adapted to press the bending sheaves toward the blank for the purpose of bending the blank into engagement with abutment means.

When the material has been bent into the correct shape, a jig is fitted down over the blank to fix it in the bent shape so that it can be removed from the bending apparatus immediately for drying, thereby enabling efficient production. The bending apparatus is also simple to adjust for blanks of various shapes.

The bending apparatus, which consists of a table with rotary actuators, templates, guide sheaves ,and bending sheaves, has hydraulic ^* rotary actuators, but the motors could

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also be pneumatic or mechanical.

The invention will be explained in greater detail in the following with the aid of an embodiment example which is illustrated in the accompanying drawings, where

Figure 1 shows a sketch of the apparatus,

Figure 2 shows a detail of the apparatus, where a contour template is shown attached to the arm of the rotary actuator,

Figure 3 shows a jig attached to the blank,

Figures 4 a,b show different positions for the arm of the rotary actuator, and

Figure 4c illustrates the use of a hydraulic cylinde instead of a rotary actuator.

The reference numbers and letters on the drawings denote the following:

S = hydraulic cylinder, axial movement

A = contour template

B = grooves for the jig

M_.-M_-M_-M. = hydraulic rotary actuators

• - _] " • ₂ ~^ ₃ ~^ Λ ⁼ detachable guide sheaves, which may be replaced by sheaves having different diameter and shapes and which run freely on an extension of the rotary actuator shaft (Figures 1, 2 and 4)

2_.-2 ₂ -3_.-3 ₂ = bending sheaves attached to respective arms of respective rotary actuators. The sheaves may be adjusted radially with respect to the axis of the rotary actuator, and run freely on a shaft journal. These sheaves may also be replaced by sheaves of different diameters. If a special configuration is desired, these sheaves may also be replaced by a contour template A, see Figure 2, which is attached to the arm of the rotary actuator.

4 = bending template attached to the piston rod

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of the cylinder , which may be replaced by templates of different shapes

5 = mounting table

6 = attachment for hydraulic rotary actuator, whi is adjustable in all planes

7 = end rest to ensure correct positioning of the blank in the bending apparatus

8 = abutment means fastened to the mounting table which provides the correct surface of abutmen for the rattan stem when bent

9 = the blank, which may be a rattan stem

10 = jig (Figure 3)

11 = hydraulic cylinder which is attached to the table, which can be moved in all planes, and which may be used for some operations instead of the rotary actuators (Figure 4c) The blank which is to be- treated is a rattan stem of up to 50 mm diameter, which is imported from the East, especially Malaysia, the Philippines and Indonesia.

The blanks are first cut to the correct length, plac in an autoclave and steamed so that they become soft and pliable. Thereafter, they are placed in the bending apparatus where by means of hydraulic bending sheaves, guide sheaves, contour template and jigs they are bent into the correct shape, removed and placed on shelves for drying.

The stem is "straight" when it is inserted into the bending apparatus, and it is placed in between the guide sheaves 1. , 1_ and a bending die 4 with its end abutting an end rest 7 (Figure 1). The cylinder S is actuated, and the bending template 4 presses the blank against abutment means 8 while at the same time the blank is pressed against the guide sheaves 1_. and 1„. The rotary actuator M.. is "coupled in and the bending sheave 2. on the arm of the rotary actuator bends the blank around the guide sheave 1_. into engagement with abutment means 8.

Hydraulic pressure holds the bending sheave 2_. in position. The rotary actuator M _? is coupled in and the

bending sheave 2~ forces the blank to bend around the guide sheave 1„ and into engagement with abutment means 8. The rotary actuators M, and M ₄ are coupled in and force the blank over the guide sheaves 1_ and 1. into engagement with abutment means 8. The blank has now been bent into the correct shape, but it cannot be removed from the bending apparatus until it has been fixed in the shape it has assumed in the bending apparatus, since it is still soft and pliable. The jig (Figure 3) is used for this purpose; the jig is fitted down over the blank and locks it in the configuration it has been given in the bending apparatus so that the blank and the jig can then be removed from the bending apparatus and placed on shelves for drying. Grooves B (Figures 2 and 3) are milled in abutment means 8 and contour template A to permit the jig to be fitted down over the blank while it remains clamped in the apparatus.

The cylinder S is adjustable in the lateral, longi¬ tudinal and vertical directions and can be angled according to which contour template 4 is being utilized. The hydraulic actuators M,. and M_ are adjustable in height and in the lateral and radial directions. If they are set at an angle in relation to the plane, for example, guide sheaves 1.. and 1,, with oblique grooves (Figures 4a, 4b) can be used. Mounted on the arms of the respective rotary actuators are bending sheaves 2. and 2~ , which are adjustable radially with respect to the axes of the respective rotary actuators, and the arms for the bending sheaves can be articulated (Figure 4b) to obtain the desired contour on the blank. The bending sheaves may be replaced by contour template (cf. Figures 2 and 4c) . The rotary actuators can be driven in both directions of rotation and are rotatable 360 . The rotary actuators are controlled by means of a hydraulic control valve which regulates the amount of fluid, an an adjustable pressure valve which controls the force and speed of the movement. The rotary actuators M-, and M. are adjustable in all planes and have the same capabilities and functions as _ _| and M_. The end rest 7 is adjustable in the longitudinal

direction to permit correct insertion of the blank which is to be bent. The apparatus is mounted on a table where the cylinder S and the rotary actuators M and M_ are mounted at a level above the table plate to permit bending in all planes. The rotary actuators M_ and M. are mounted on the table plate, and are adjustable over the entire table. Similarly, abutment means 8 are mounted on the table. In cases where only one end of the stem is to be bent, a hydraulic cylinder 11 (Figure 4c) may be used instead of a hydraulic actuator. The cylinder is mounted on the table. It can be tilted about the point of attachment and is pivotable so that the blank will not impinge incorrectly against the "angle" which bends the blank.

After the blank has been bent into the correct shape (Figure 2), it is ready to be removed from the bending apparatu In cases where the blank is to be given a special configuration the bending sheave which is attached to the arm of the rotary actuator can be replaced by a contour template, A on Figure 2, or by a die in addition to the bending sheave 2. In abutment means 8, which is bolted to the table 5, and in the contour template A and the bending template 4, grooves B have been milled for abutment means 10 (cf. Figure 2). The jig 10 is made of a rigid material and provided with "ears" and offsets, and it is fitted down over the blank when the blank still lies clamped in the bending apparatus. When the bending apparatus is subsequently driven back into its starting position, the blank will be released but will be locked in the same position as when it was clamped in the apparatus (Figure 3) .

The blank is then removed from the bending apparatus with the jig 10 attached and may be placed on shelves for drying. When the blank is dry it will retain its shape, and the jig can be removed and is ready to be used again. Produc¬ tion can thus run continuously assuming one has a sufficient number of jigs.

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