CN216544821U

CN216544821U - Material belt detection mechanism, feeding device and tire forming machine

Info

Publication number: CN216544821U
Application number: CN202122615329.7U
Authority: CN
Inventors: 刘春来
Original assignee: Safe Run Intelligent Equipment Co Ltd
Current assignee: Safe Run Intelligent Equipment Co Ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-05-17
Anticipated expiration: 2031-10-28
Also published as: WO2023072222A1

Abstract

The utility model belongs to the technical field of tire forming, and discloses a material belt detection mechanism, a feeding device and a tire forming machine. The material area detection mechanism is used for detecting the material area of being carried by the feed frame, and it includes: the base is used for connecting the feeding frame; the swing frame is arranged on the base in a swinging mode and is provided with a detection position and a trigger position; when the swing frame is positioned at the detection position, a first gap smaller than the thickness of the material belt is formed between the swing frame and the conveying surface of the feeding frame; when the swing frame is positioned at the triggering position, a second gap larger than the first gap is formed between the swing frame and the conveying surface of the feeding frame; the detection unit is configured to form a trigger signal when the swing frame is located at the trigger position; and a reset unit configured to hold the swing frame at the detection position. The feeding device and the tire building machine both comprise the material belt detection mechanism. The material belt detection mechanism provided by the utility model can avoid the damage of the feeding device caused by the fact that the belt layer is not conveyed according to a preset mode in the tire forming operation.

Description

Material belt detection mechanism, feeding device and tire forming machine

Technical Field

The utility model relates to the technical field of tire molding, in particular to a material belt detection mechanism, a feeding device and a tire molding machine.

Background

In a tire building operation, a belt strip is fed through a serviser to a belt drum for building a tire tread. Specifically, as shown in fig. 1, the feeding device is disposed below the belt drum, and generally includes a feeding frame 100 'and a timing belt revolving around the feeding frame 100', a belt strip 300 'of a fixed length is fed into the timing belt from a receiving end (left side in fig. 1) of the timing belt, and a head portion of the belt strip is conveyed to an output end (right side in fig. 1) of the timing belt along with the timing belt, the output end is located immediately below the belt drum 200', and when the belt drum 200 'receives the belt strip 300', the belt strip rotates at the same linear speed as the conveying speed of the timing belt, so as to wind up the head portion of the belt strip 300 ', until the belt strip 300' is completely wound up to the drum surface.

However, as shown in fig. 2, since the belt tape 300 ' mainly made of unvulcanized rubber has a certain viscosity, there is a certain possibility that the belt tape 200 ' is adhered to the timing belt and not wound by the belt drum 200 ' during the winding of the belt tape 200 ' by the belt drum 200 ', and the timing belt is damaged and affects the tire formation as the timing belt is continuously conveyed to the lower side of the feeding device and pushed.

Therefore, the above problems need to be solved.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a material belt detection mechanism, a feeding device and a tire building machine, which are used for avoiding the problem that the feeding device is damaged due to the fact that a belt layer is not conveyed according to a preset mode in the tire building operation.

In order to achieve the purpose, the utility model adopts the following technical scheme:

a material area detection mechanism for detecting a material area conveyed by a supply rack, comprising:

the base is used for connecting the feeding frame;

the swing frame is arranged on the base in a swinging mode and is provided with a detection position and a trigger position; when the swing frame is located at the detection position, a first gap smaller than the thickness of the material belt is formed between the swing frame and the conveying surface of the feeding frame; when the swing frame is located at the triggering position, a second gap larger than the first gap is formed between the swing frame and the conveying surface of the feeding frame;

a detection unit configured to form a trigger signal when the swing frame is located at the trigger position; and

a reset unit configured to hold the swing frame at the detection position.

Preferably, the swing frame includes:

the swing arm is pivoted to the base and is positioned on the side part of the feeding frame; and

the detection arm is connected to the swing arm, extends to the conveying surface of the feeding frame, and can swing up and down along with the swing arm.

Preferably, the detection arm is detachably connected to the swing arm.

Preferably, the detection unit includes:

a photoelectric switch; and

the light reflecting plate is used for reflecting the light emitted by the light emergent end of the photoelectric switch to the light receiving end of the photoelectric switch; when the swing frame is located at the detection position, the swing frame is inserted into the light transmission path, and when the swing frame is located at the trigger position, the swing frame is moved out of the light transmission path.

Preferably, the reset unit includes:

the stopping part can be abutted against the swing frame positioned at the detection position;

one end of the elastic element is connected with the feeding frame, and the other end of the elastic element is connected with the swinging frame; when the swing frame is located at the trigger position, the elastic element can generate elastic deformation, and when the elastic element recovers to deform, the swing frame can be pulled to reset to abut against the stop part.

Preferably, the stopper includes:

the top thread seat is used for connecting the feeding frame; and

the jackscrew is in threaded connection with the jackscrew seat, and one end of the jackscrew, which extends out of the jackscrew seat, is abutted against the swing frame.

Preferably, the reset unit further includes an adjustment portion configured to an elastic deformation degree of the elastic member when the swing frame is at the detection position.

Preferably, the elastic member is a tension spring, and the adjusting portion includes:

the adjusting disc is pivoted with the feeding frame and is hooked with one end of the tension spring, a strip hole formed around the adjusting disc and the pivot of the feeding frame is formed in the adjusting disc, and the strip hole is opposite to a screw hole formed in the feeding frame; and

and the bolt can penetrate through the strip hole to be in threaded connection with the screw hole so as to lock the adjusting disc on the feeding frame.

In order to achieve the purpose, the utility model also adopts the following technical scheme:

the utility model provides a feeding device, includes the feed frame, be equipped with the hold-in range of gyration conveying on the feed frame, the hold-in range is used for carrying the material area, feeding device still includes as above material area detection mechanism.

To achieve the purpose, the utility model also adopts the following technical scheme:

the utility model provides a tire building machine, includes the belted drum and as above feedway, the belted drum set up in the terminal top of feed frame is in order to receive the belted layer material area that the hold-in range was carried, material area detection mechanism set up in the low reaches of belted drum.

The utility model has the beneficial effects that:

the swing frame of the belt detection mechanism provided by the utility model can be driven by a belt layer belt which cannot be wound by a belt drum to swing, the detection unit is triggered based on the position change of the detection swing frame, and then a trigger signal can be transmitted to the driving mechanism of the synchronous belt or the control end of the driving mechanism, so that the driving mechanism is stopped conveniently, the belt layer belt is cleaned manually, or the synchronous belt is operated reversely, and the belt layer belt is retracted to the upstream of the belt drum to be fed again. The feeding device and the tire forming machine provided by the utility model can avoid the problem that the synchronous belt is damaged to influence the tire forming because the belt layer is not conveyed according to a preset mode.

Drawings

FIG. 1 is a schematic diagram of a belt material belt provided by a belt drum take-up and supply device in the prior art;

FIG. 2 is a schematic view of a prior art belt supply structure provided by a belt drum without a supply reel;

FIG. 3 is a schematic view showing a partial structure of a feeding device in an embodiment of the present invention;

fig. 4 is a schematic perspective view of a tape detection device according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a swing frame of the tape detection apparatus in the embodiment of the present invention when the swing frame is at a detection position;

fig. 6 is a schematic structural diagram of a swing frame of the tape detection apparatus in an embodiment of the present invention when the swing frame is in a trigger position.

In the figure:

100', a feeding frame; 200', a belt drum; 300', a belt material strip;

100. a feeding frame; 200. a belt drum; 300. a belted layer material belt;

1. a base;

2. placing a frame; 21. swinging arms; 22. a detection arm; 23. briquetting;

3. a detection unit; 31. a mounting frame; 32. a photoelectric switch; 33. a reflector;

4. a reset unit; 41. a stopper portion; 411. a jackscrew seat; 412. carrying out top thread; 42. a tension spring; 43. an adjustment section; 431. an adjusting disk; 4311. and (4) forming a bar hole.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

This embodiment provides a material area detection mechanism, and this material area detection mechanism is used for detecting the material area of being carried by the feed frame to can be applied to the material area and have the judgement that does not get into/leave and be detected the station, also can be applied to in the scene such as length that the time length that calculates the material area is long when feed frame conveying speed and there is material to detect the structure state.

The embodiment specifically applies the tape detecting mechanism to a belt feeding device of a tire building machine to solve the problem that the feeding device is damaged by occasionally winding a belt into a timing belt in the tire building operation of the tire building machine, which is described in detail below.

Because the belt material strip is soft and sticky, the belt material strip cannot be peeled from the synchronous belt by the aid of a material shovel or a guide mechanism and the like in the process of winding the belt material strip on the belt drum, and the belt material strip is guided to the drum surface of the belt drum. Therefore, for avoiding the belt material belt to bulge and fail and then cause the belt to pile and crowd and damage the condition of hold-in range, feasible method is that the belt detection mechanism that this embodiment provided is set up in the low reaches of belt drum along hold-in range direction of delivery, after belt detection mechanism detected the belt, can judge that this belt fails to be taken the rolling by the belt drum, and then stop feedway based on the trigger signal system that belt produced, thereby can avoid belt to take the belt to carry along the hold-in range, cause the belt to pile and crowd and damage the condition of hold-in range.

Specifically, as shown in fig. 3, a belt drum 200 of the tire building machine and a serviser for supplying a belt strip 300 to the belt drum 200. The feeding device includes a feeding frame 100, and a timing belt (not shown) for rotating and conveying the belt material strip 300 is disposed on the feeding frame 100. The belt strip 300 with fixed length is input from the receiving end (left side in fig. 3) of the synchronous belt, the head of the belt strip 300 is conveyed forward to the output end (right side in fig. 3) of the synchronous belt along with the synchronous belt, the output end is located below the belt drum 200, when the belt drum 200 receives the belt strip 300, the belt strip 300 rotates at the same linear speed as the conveying speed of the synchronous belt, and therefore the head of the belt strip 300 is wound until the belt strip 300 is completely wound on the drum surface. The belt detection mechanism is arranged at the downstream of the belt drum 200 along the conveying direction of the synchronous belt, so as to detect the belt material belt 300 which is not wound by the belt drum 200, and transmit a trigger signal to the driving mechanism of the synchronous belt or the control end of the driving mechanism after being triggered by the belt material belt 300, so that the driving mechanism is stopped conveniently, the belt material belt 300 is cleaned manually, or the synchronous belt is operated reversely, so that the belt material belt 300 returns to the upstream of the belt drum 200 to perform the feeding action again.

Referring to fig. 3 in combination with fig. 4, the tape detecting mechanism includes a base 1, a swing frame 2, a detecting unit 3, and a resetting unit 4. The base 1 is used for connecting a feeding frame 100, a swing frame 2 is arranged on the base in a swinging mode, and at least one detection position and one triggering position are set in a swinging path of the swing frame 2. The reset unit 4 is configured to hold the swing frame 2 at the detection position. As shown in fig. 5, when the swing frame 2 is located at the detection position, the swing frame 2 has a first gap d with the conveying surface of the supply frame 100₁,d₁Greater than or equal to 0, but less than the thickness of belted layer material area 300 to when belted layer material area 300 is carried to the rocker 2 position by the hold-in range, the belted layer can intervene between the conveying face of rocker 2 and hold-in range, and then overcome the reset effect of reset unit 4 to rocker 2 and drive rocker 2 to swing, make rocker 2 switch to the position of triggering. As shown in fig. 6, when the swing frame 2 is located at the triggering position, a gap d larger than a first gap d is formed between the swing frame 2 and the conveying surface of the supply frame 100₁Second gap d₂. The detection unit 3 is configured to detect the position of the swing frame 2 and form the above-mentioned trigger signal when the swing frame 2 is in the trigger position.

Specifically, with continued reference to fig. 4, the base 1 is fixed on the side of the feeding frame 100, and the swing frame 2 includes a swing arm 21 and a detection arm 22, wherein the swing arm 21 is pivoted to the base 1, is located on the same side of the feeding frame 100 as the base 1, and can rotate around a horizontal pivot disposed between the swing arm and the base 1. The detecting arm 22 is preferably a smooth cylindrical rod, one end of which is connected to the swing arm 21, and the other end of which extends inward from the side of the supply frame 100 to above the conveying surface of the supply frame 100, so that the detecting arm 22 can swing up and down with the swing arm 21.

As shown in fig. 3, the swing arm 21 is disposed at the front end of the supply frame 100 radially outside the bending portion of the timing belt, so that the swing arm 21 can be disposed immediately downstream of the belt drum 200 without intentionally extending the timing belt for the purpose of detecting the belt 300.

Please refer to fig. 5 and fig. 6, wherein fig. 5 is a schematic structural view of the swing frame 2 at the detection position, and fig. 6 is a schematic structural view of the swing frame 2 at the trigger position. When the belt strip 300 is normally wound up by the belt drum 200, or the belt strip 300 is not wound up by the belt drum 200 and has not been delivered to below the detecting arm 22, the entire swing frame 2 is in the detecting position shown in fig. 5. When the belt material tape 300 which is not wound by the belt drum 200 is continuously conveyed to the bending position at one end of the synchronous belt by the synchronous belt, the belt material tape 300 is inserted into a gap between the detection arm 22 and the conveying surface of the synchronous belt, so that the detection arm 22 is pushed, the detection arm 22 drives the swing arm 21 to rotate and swing by an angle around the pivot of the swing arm 21 and the base 1 according to the clockwise direction of the view directions of fig. 5 and 6, and the whole swing frame 2 is in the triggering position shown in fig. 6.

Referring to fig. 4, fig. 5 and fig. 6, in the present embodiment, the detecting unit 3 includes a mounting frame 31 mounted on the feeding frame 100, and a photoelectric switch 32 and a light reflecting plate 33 both mounted on the mounting frame 31, wherein the photoelectric switch 32 has a light emitting end and a light incident end disposed on the same side surface thereof, the light emitting end is capable of emitting infrared light outwards, the light incident end is configured to receive infrared light, and the light reflecting plate 33 is disposed opposite to the photoelectric switch 32, so that the infrared light emitted from the light emitting end can be reflected by the light reflecting plate 33 to the light incident end, so that the photoelectric switch 32 generates a trigger signal. For detecting the position of the swing frame 2, a gap allowing the swing arm 21 to be inserted is formed between the photoelectric switch 32 and the reflector 33, when the swing frame 2 is located at the detection position, the swing frame 2 is inserted into the propagation path of the infrared light to block the infrared light from irradiating to the light incident end, the photoelectric switch light does not generate a trigger signal, and when the swing frame 2 is located at the trigger position, the swing arm 21 rotates along with the detection arm 22 and moves out of the propagation path of the infrared light, so that the infrared light is allowed to irradiate to the light incident end, and the photoelectric switch light generates the trigger signal.

Of course, in other embodiments, the detection unit 3 is not limited to adopting the above-described structure. For example, a set of opposed photoelectric switches 32 may be adopted, such that the light emitting end and the light receiving end of the opposed photoelectric switches 32 are respectively disposed on two sides of the swing arm 21, so as to determine the position of the swing arm 21 according to whether the light receiving end can receive the infrared light emitted from the light emitting end. Alternatively, a contact/proximity switch capable of being in the above-mentioned detection position and/or trigger position at the swing arm 21 may be used, so that the position of the swing arm 21 is determined based on the detection signal of the contact/proximity switch, which is not limited herein.

In this embodiment, the reset unit 4 may include a stopper 41 and an elastic element, and the stopper 41 can abut against the swing arm 21 of the swing frame 2 located at the detection position, so as to support the swing frame 2 and limit the swing stroke of the swing arm 21. The elastic element is preferably a tension spring 42, one end of the tension spring 42 is connected with the feeding frame 100, and the other end is connected with the swing arm 21 of the swing frame 2. When the swing frame 2 is located at the triggering position, the tension spring 42 is stretched by the rotating swing arm 21 to generate elastic deformation, and after the belt material strap 300 between the detection arm 22 and the timing belt is removed, the tension spring 42 can restore the deformation, so that the swing frame 2 is pulled to be reset to the detection position abutting against the stop portion 41.

In order to adapt to the detection of the belt strips 300 with different thicknesses, on one hand, the detection arms 22 with different diameters can be replaced, namely, the gap between the detection arm 22 and the synchronous belt is adjusted, therefore, the swing arm 21 and the detection arm 22 can be detachably connected, and as shown in fig. 4, the detection arm 22 can be clamped and fixed by matching a pressing block 23 with the swing arm 21. On the other hand, the position of the detection position of the swing frame 2 set in advance, that is, the static position of the swing arm 21 at the detection position, may be indirectly adjusted by adjusting the position where the stopper 41 abuts against the swing frame 2. As shown in fig. 3 and 4, the stopping portion 41 of the present embodiment preferably includes a top thread 412 seat 411 connected to the feeding frame 100, and a top thread 412 screwed with the top thread 412 seat 411, the top thread 412 is screwed downward and upward and extends out of the upper end of the top thread 412 seat 411, one end of the top thread 412 extending out of the top thread 412 seat 411 abuts against the swing frame 2, so that the static position of the swing arm 21 at the detection position can be adjusted by adjusting the relative screwing position of the top thread 412 and the top thread 412 seat 411, and the gap between the detection arm 22 and the timing belt can be adjusted.

It should be noted that if the belt strip 300 is too soft in a specific production situation, after the belt strip 300 is inserted between the detecting arm 22 and the conveying surface of the timing belt, it may not overcome the elastic force of the elastic element, and the detecting arm 22 and the timing belt may be squeezed flat and continue to enter the interior of the feeding device along with the conveying of the timing belt. Therefore, in the embodiment, the resetting unit 4 further includes an adjusting portion 43, and the adjusting portion 43 can adjust the elastic deformation degree of the elastic element when the swing frame 2 is at the detection position according to the hardness degree of the belt 300 and the reduction of the stiffness coefficient of the elastic element in long-term use.

As shown in fig. 3, in the present embodiment, the adjusting portion 43 includes an adjusting plate 431 and at least one bolt (not shown), the adjusting plate 431 is pivotally connected to the feeding frame 100 and hooked to one end of the tension spring 42 for connecting to the feeding frame 100, an arc-shaped bar hole 4311 is provided on the adjusting plate 431 around the pivot of the feeding frame 100, the bar hole 4311 is opposite to a screw hole provided on the feeding frame 100, and the bolt can pass through the bar hole 4311 and be screwed to the screw hole. After the bolts are unlocked, the stretching degree of the tension spring 42 can be adjusted by rotating the adjusting disc 431, and after the adjustment is completed, the bolts are locked again, so that the adjusting disc 431 can be locked on the feeding frame 100.

It should be noted that, in other embodiments, the elastic element may also be a compression spring or a spring plate, and based on the type of the elastic element, the connection manner and the relative installation position between the elastic element and the swing arm 21 are correspondingly adjusted, and the corresponding auxiliary installation component is selected, which is not described herein again. Meanwhile, after the type of the elastic element is adjusted, the adjusting portion 43 also needs to be adjusted in structure, for example, in an embodiment that the compression spring is used as the elastic element, the compression spring can be abutted by a stopper that is movably locked, so that the compression spring is compressed between the swing arm 21 and the stopper, and the degree of elastic deformation of the compression spring when the swing frame 2 is at the detection position can be adjusted by adjusting the distance between the stopper and the swing arm 21.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations, and substitutions will occur to those skilled in the art without departing from the scope of the present invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A material tape detection mechanism for detecting a material tape conveyed by a supply rack (100), comprising:

a base (1) for connecting the supply frame (100);

the swing frame (2) is arranged on the base (1) in a swinging mode and is provided with a detection position and a trigger position; when the swing frame (2) is located at the detection position, a first gap smaller than the thickness of the material belt is formed between the swing frame (2) and the conveying surface of the feeding frame (100); when the swing frame (2) is located at the triggering position, the swing frame (2) and the conveying surface of the feeding frame (100) have a second clearance which is larger than the first clearance;

a detection unit (3) configured to form a trigger signal when the swing frame (2) is located at the trigger position; and

a reset unit (4) configured to hold the swing frame (2) at the detection position.

2. Tape detection mechanism according to claim 1, wherein the pendulum (2) comprises:

the swing arm (21) is pivoted to the base (1), and the swing arm (21) is positioned on the side part of the feeding frame (100); and

the detection arm (22) is connected to the swing arm (21), and the detection arm (22) extends to the position above the conveying surface of the feeding frame (100) and can swing up and down along with the swing arm (21).

3. Tape detection mechanism according to claim 2, wherein the detection arm (22) is detachably connected to the swing arm (21).

4. Tape detection mechanism according to claim 1, wherein the detection unit (3) comprises:

an opto-electric switch (32); and

a reflector (33) for reflecting light emitted from the light emitting end of the photoelectric switch (32) to the light receiving end of the photoelectric switch (32); when the swing frame (2) is located at the detection position, the swing frame (2) intervenes in the propagation path of the light, and when the swing frame (2) is located at the trigger position, the swing frame (2) moves out of the propagation path of the light.

5. Tape detection mechanism according to claim 1, wherein the reset unit (4) comprises:

a stopper (41) capable of abutting against the swing frame (2) at the detection position;

one end of the elastic element is connected with the feeding frame (100), and the other end of the elastic element is connected with the swinging frame (2); when the swing frame (2) is located at the triggering position, the elastic element can generate elastic deformation, and when the elastic element recovers to deform, the swing frame (2) can be pulled to reset to abut against the stop part (41).

6. The tape detecting mechanism according to claim 5, wherein the stopper (41) comprises:

the top thread seat (411) is used for connecting the feeding frame (100); and

the jackscrew (412) is in threaded connection with the jackscrew seat (411), and one end, extending out of the jackscrew seat (411), of the jackscrew (412) abuts against the swing frame (2).

7. Tape detection mechanism according to claim 5, wherein the reset unit (4) further comprises an adjustment portion (43), the adjustment portion (43) being configured to adjust the degree of elastic deformation of the elastic element when the swing frame (2) is in the detection position.

8. The tape detecting mechanism according to claim 7, wherein the elastic element is a tension spring (42), and the adjusting portion (43) comprises:

the adjusting disc (431) is pivoted with the feeding frame (100) and is hooked with one end of the tension spring (42), a strip hole (4311) formed around the adjusting disc (431) and the pivot of the feeding frame (100) is formed in the adjusting disc, and the strip hole (4311) is opposite to a screw hole formed in the feeding frame (100); and

a bolt threadably engaged with the threaded hole through the bar hole (4311) to lock the adjustment plate (431) to the feed frame (100).

9. A feeding device comprising a feeding frame (100), wherein a rotary conveying synchronous belt is arranged on the feeding frame (100), and the synchronous belt is used for conveying a material belt, and the feeding device further comprises a material belt detecting mechanism according to any one of claims 1 to 8.

10. A tyre building machine, characterized in that it comprises a belt drum (200) and an serviser according to claim 9, said belt drum (200) being arranged above the end of said supply frame (100) so as to be able to receive a belt strip (300) delivered by said timing belt, said strip detection means being arranged downstream of said belt drum (200).