Method for joining a belt having a reinforced structure with interpenetrated spirals

Abstract

A method for joining a belt having a reinforcement structure having a plurality of spirals connected to each other by transverse wires includes compressing the belt along two transverse compression zones and extracting a transverse wire while the belt is being compressed along the transverse compression zones.

Claims

1. A method for joining a belt into a closed loop, the belt having a reinforcement structure incorporated in a filling material, wherein the reinforcement structure includes a plurality of spirals parallel to each other and transverse with respect to a longitudinal axis of the belt, wherein adjacent spirals are interpenetrated and are connected to each other by transverse wires parallel to the spirals and wherein each of the transverse wires extends into two adjacent interpenetrating spirals, wherein the method comprises: identifying a transverse line along which the belt is to be cut, incising a lateral zone of a face of the filling material in a vicinity of one end of a first transverse wire which extends along said transverse line, and extracting the one end of said first transverse wire outside the filling material, compressing the belt along two transverse compression zones which are parallel and located on opposite sides with respect to said transverse line such that diameters of adjacent interpenetrating spirals through which the first transverse wire extends increase, gripping said one end of the first transverse wire protruding outside the filling material and extracting the first transverse wire by applying a traction in a direction transverse to the longitudinal axis while the belt is compressed along said transverse compression zones, disengaging said adjacent interpenetrating spirals which were previously joined together by the first transverse wire which has been extracted, cutting the filling material between said adjacent interpenetrating spirals disengaged from each other, interpenetrating end spirals of two opposite ends of the belt so as to be mutually interpenetrated, and inserting a new transverse wire into the mutually interpenetrated end spirals to join the belt in a closed loop.

2. The method of claim 1, wherein said transverse compression zones are moved toward each other in a direction parallel to the longitudinal axis of the belt.

3. The method of claim 1, wherein each of said transverse compression zones is formed by damping the belt between two blocks located on opposite faces of the belt.

4. The method of claim 1, wherein said transverse compression zones extend in a transverse direction to the longitudinal axis between two opposite lateral edges of the belt.

5. The method of claim 1, wherein the step of disengaging said adjacent interpenetrating spirals after the extraction of the first transverse wire is carried out by bending the belt along a folding line extending between said disengaged adjacent interpenetrating spirals.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described in detail with reference to the annexed drawings, which are given by way of non-limiting example only, wherein:

(2) FIGS. 1 and 2 are perspective views which schematically show a preliminary step of the joining method according to the present invention,

(3) FIGS. 3 and 4 are lateral sections illustrating the step of compressing the wire,

(4) FIG. 5 is a schematic perspective view which shows the step of extracting the transverse wire,

(5) FIG. 6 is a section showing the belt at the end of the extraction step,

(6) FIGS. 7 and 8 are sections showing the step of cutting the coating, and

(7) FIG. 9 is a perspective view showing the step of joining the belt.

DETAILED DESCRIPTION

(8) Referring to FIGS. 1 and 2, reference number 10 indicates a belt having a reinforcing structure 12 including a plurality of spirals 16 having the respective axes parallel to each other and oriented orthogonally with respect to a longitudinal axis A of the belt 10. Mutually adjacent spirals 16 are interpenetrated and connected to each other by transverse wires 18 which are parallel to the axes of the spirals. Each transverse wire 18 extends into two adjacent interpenetrating spirals 16. The spirals 16 may be formed of a monofilament polyester wire. In the same way, the transverse wires 18 may be formed of a monofilament polyester wire, which may have the same diameter as the wire forming the spirals 16.

(9) The reinforcing structure 12 is incorporated in a filling material 13 which penetrates inside the spirals 16. A coating 14 is applied on one face of the filling material 13. The filling material 13 and the coating 14 may be formed of any material used for manufacturing conveyor belts, such as e.g. natural or synthetic rubber, nitrile, silam, Teflon, SBR. The coating 14 may also include a fibrous material, such as e.g. cotton or felt. Belts having this construction are known in the state of the art and are commercially available.

(10) In use, belts 10 are joined into a closed loop in order to be mounted on rollers of a belt conveyor. FIGS. 1-9 schematically show the sequence of operations needed to adjust the length of belt 10 as desired, and to join the opposite ends of belt 10 together.

(11) In a first step, shown in FIG. 1, the length of belt 10 is measured and a transverse line L is identified along which belt 10 is to be cut, in order to obtain the desired length. Then, an operator incises a face 20 of the filling material 13 in the vicinity of a lateral edge of belt 10. The incision of face 20 is carried out near the end of a transverse wire 18 extending along a line L.

(12) Subsequently, as shown in FIG. 2, the operator grips, through the incision, the end of the wire 18 extending along line L and extracts the end of the transverse wire 18 through the filling material 13.

(13) Referring to FIGS. 3 and 4, the belt 10 is compressed along two transverse compression zones 24, 26, which are parallel and located on opposite sides with respect to the line L along which the belt 10 is to be cut. Each transverse compression zone 24, 26 extends transversally with respect to the longitudinal axis A of belt 10 and throughout the width of belt 10. The compression of the belt 10 may be achieved by compressing opposite faces 20, 22 of belt 10 between two blocks 28, clamped one against the other, e.g. by screws and bolts.

(14) The extraction of the end of transverse wire 18 through the filling material 13 of belt 10 may be performed either before or after compressing the belt 10 between blocks 28, 30.

(15) Referring to FIG. 4, after compressing the belt 10 along the transverse compression zones 24, 26, the blocks 28, 30 which compress the belt 10 may be approached to each other, as shown in FIG. 4.

(16) The transverse compression zones 24, 26 compress respective spirals 16 located on opposite sides of line L and connected together by the transverse wire 18 which is to be extracted. The compression of the two mutually interpenetrating spirals 16 from opposite sides of separation line L causes an increase of the diameter of those portions of the spirals which are interpenetrated with each other and engaged by the transverse wire 18. This size increase of the mutually interpenetrated portions of spirals 16 is enhanced by the compression blocks 28, 30 approaching each other.

(17) Referring to FIG. 5, while belt 10 is being compressed between the two pairs of blocks 28, 30, the operator grips the end of the transverse wire 18 protruding from face 20 of the filling material 13 by using tongs, and extracts the transverse wire 18 by applying a traction in a transverse direction with respect to longitudinal axis A of belt 10. The extraction of the transverse wire 18 is made much simpler because belt 10 is compressed along the transverse zones in the immediate vicinity to the wire 18 which is to be extracted. Indeed, as stated in the foregoing, said compression tends to increase the size of the spirals located between the two compression zones 24, 26, and helps detaching the transverse wire 18 from the filling material 13 which penetrates into the spirals 16.

(18) After completing the extraction of the transverse wire 18, the two contiguous spirals 16, which were previously connected with each other by the transverse wire 18 which has been removed, are still kept united with each other in the longitudinal direction by the filling material 13 and by the coating 14.

(19) Now, as shown in FIG. 7, the belt 10 is bent so as to mutually disengage the two contiguous spirals which were previously connected by the transverse wire 18 which has been removed. Then, the filling material 13 and the coating 14 are cut between the two contiguous spirals 16, which are now disengaged, as shown in FIGS. 7 and 8.

(20) Now, as shown in FIG. 9, the two opposite ends of belt 10 are contacted with each other, and the two spirals 16 adjacent to the transverse edges of the belt are interpenetrated with each other. Finally, a new transverse wire 18 is inserted between the two spirals 16 located at the opposite ends of belt 10, so as to join the opposite ends of belt 10.

(21) For the operator performing joining, the most difficult step consists in extracting the transverse wire in order to disengage two contiguous spirals. As already stated in the foregoing, this operation is highly simplified by compressing the belt from opposite sides of the transverse wire 18 which is to be extracted, and the wire extraction is performed while the belt is being compressed in the transverse zone adjacent to the wire to be extracted.

(22) Thanks to this solution, it is no longer necessary to incise the surface throughout the length of the belt, nor is it necessary to insert a lubricant through the transverse incision, as it was envisaged in the method according to the known art, to make the extraction of the transverse wire easier. Moreover, the method according to the present invention minimizes the risk of damaging the belt.

(23) Of course, without prejudice to the principle of the invention, the implementation details and the embodiments may vary appreciably from what has been described and shown herein, without departing from the scope of the invention as set forth by the Claims that follow.