39results about "Blow heads" patented technology

The invention relates to the technical field of glass bottle processing, and provides a glass wine bottle blowing forming process which comprises the following steps: S1, taking materials and cogging, and putting a glass raw material into a primary bubble mold to prepare a glass material ball; s2, blowing primary bubbles: blowing air into the frit balls to prepare glass bubbles; s3, in-mold shaping: putting the glass bulb into a forming mold, and blowing air into the glass bulb to obtain a glass wine bottle; s4, demolding and cooling; wherein blowing of the glass wine bottle is carried out in the workbench, the primary foaming mold and the forming mold are both arranged on the workbench, and the primary foaming mold is located above the forming mold; an overturning shaft is rotationally connected between the primary foaming mold and the forming mold, and a blowing pipe is connected to the overturning shaft. According to the blowing forming process for the glass wine bottle, the transferring convenience of the glass bulbs can be improved.

The invention discloses a glass tube blowing air automatic control device which comprises an automatic blowing control device, a blowing driving jig is installed on the outer side of the automatic blowing control device, the blowing driving jig is installed on a glass tube blowing table, meanwhile, a blowing limiting plugging jig is installed on the other side of the surface of the glass tube blowing table, and the blowing limiting plugging jig is installed on the other side of the surface of the glass tube blowing table. A glass tube body is clamped and fixed between the blowing limiting plugging jig and the blowing driving jig, and a self-adaptive blowing mold mechanism is mounted above the middle part of the glass tube body. According to the automatic control device for blowing air of the glass tube, the mold A and the mold B of the self-adaptive blowing mold mechanism can synchronously move inwards for mold closing, the mold A and the mold B can be accurately attached to the forming position in the middle of the glass tube body, stable constraint is provided from the outside, and the problem of deformation caused by no constraint or non-uniform constraint during blowing forming of a glass product is effectively avoided; and the product design form can be kept, and the forming deviation is reduced.

This disclosure provides a straightening device for the main shaft of a danner machine, relating to the field of danner machine technology. The danner machine main shaft straightening device includes a measuring component and a straightening component. The measuring component measures the curvature of the danner machine main shaft, while the straightening component is spaced apart from the danner machine along the axial direction of the main shaft and is used to straighten the main shaft on the danner machine based on the curvature. The measuring component provides accurate data for the straightening component's straightening work; the straightening component straightens the main shaft based on the curvature data provided by the measuring component. The straightening component's spaced-apart arrangement along the axial direction of the main shaft allows the straightening device to directly straighten the main shaft on the danner machine, ensuring the normal operation of the danner machine.

This invention provides a glass flake preparation apparatus, comprising, from top to bottom, a dipping module, a blowing module, and a crushing module. The dipping module includes a blowing head, a guide rail, and multiple crucibles. The blowing head has a slider that slides laterally downwards on the guide rail. The slider is fixedly connected to the blowing head via a telescopic rod, driving the blowing head to dip downwards. The multiple crucibles are arranged below the guide rail along its direction. The blowing module includes a funnel-shaped blowing cylinder and a valve. The valve is located at the bottom outlet of the blowing cylinder, and a blowing port is opened at the top of the blowing cylinder. The crushing module includes a receiving cylinder and a crusher. The crusher is located below the inlet of the receiving cylinder. The advantages of this invention are: it achieves a technological breakthrough in the efficient preparation of glass flakes with various compositions on the same device, integrating glass melting, blowing, and crushing processes into one device, and effectively avoiding the problem of glass flake powder flying everywhere during the crushing process.

The utility model discloses a blowing head air outlet structure of a glass bottle opening, which relates to the field of glass bottle production and is technically characterized by comprising a blowing head body, a cooling cavity is arranged at the bottom of the blowing head body, a blowing and pressing cavity is arranged in the cooling cavity, a blowing and pressing pipe is arranged in the blowing and pressing cavity, and the blowing and pressing pipe is connected with the blowing head body. A cooling cavity is formed in the blowing head body, a plurality of first air inlet holes and a plurality of first exhaust holes are formed in the outer edge of the blowing head body, the first air inlet holes and the first exhaust holes are communicated with the cooling cavity, the first air inlet holes are communicated with an external cooling air source, and a plurality of adjusting seats are arranged on the outer edge of the blowing head body; the technical problem that due to the fact that a cooling air source is far away from an air blowing head, pressure transmission of air from the cooling air source to the air blowing head is delayed, and therefore it is difficult to adjust the air supply amount of the cooling air source to enable the air pressure of a cooling cavity to reach the standard value of the technology is solved.

A forming die for a glass bottle blowing process comprises a die set, and the die set comprises a first die body and a plurality of die bodies arranged according to the curved surface portion of the surface of a glass bottle body. The first mold body is configured to be driven to extrude an opening part of the glass blank, each mold body at least corresponds to a curved surface part on the glass bottle body, each mold body corresponds to a specific curved surface area of the glass bottle body, and a temperature sensor and an independent cooling channel are arranged in each mold body; the temperature of different areas of the mold is monitored in real time and accurately and independently regulated and controlled, so that the problem of uneven heat dissipation caused by overall cooling of a traditional mold is solved, local overheating or supercooling caused by the thickness difference and shape curvature change of a bottle body can be compensated, the cooling uniformity of a glass bottle is improved, and the service life of the glass bottle is prolonged. Bottle body deformation, non-uniform thickness and internal stress concentration caused by temperature gradient are reduced, and finally a glass bottle product which is accurate in size, uniform in wall thickness and high in appearance quality is obtained.

The application provides a glass blowing equipment with a rapid cooling structure, relates to the field of glass blowing, and comprises an operation table, a secondary table fixedly connected to the top of the operation table, a tertiary table fixedly connected to the top of the secondary table, a gas pump fixedly connected to the top of the operation table, a gas injection pipe connected to the top of the gas pump through a pipeline, and an operation pipe arranged on the outside of the gas injection pipe. The pressure sensor of the detection pipe can be used for real-time monitoring of the air pressure on the inside of the glass cavity. The electric telescopic rod can be fed back in real time through the pressure sensor data, so that the telescopic part of the electric telescopic rod can push the supporting spring to elastically contract. The current air pressure of the glass product can be adjusted in real time according to the elastic tension of the press switch. The problems that the existing blowing equipment is inconvenient for the operator to feel the cavity pressure inside the glass product in real time when the machine is used to inject air and is inconvenient for the operator to improve the feeling degree of the glass product blowing during the operation process are solved.

The invention discloses a blowpipe air supply device for a glass forming furnace and integrated air supply equipment, and belongs to the technical field of design of air supply equipment for glass forming furnaces. The blowpipe air supply device comprises an air collecting pipe, an air outlet is formed in the wall face of the air collecting pipe and connected with a pressure reducing valve in a matched mode, the pressure reducing valve is connected with a flow meter through a pipeline, the flow meter is connected with one end of a hose, and the other end of the hose is arranged at a pipe opening of the forming furnace blowpipe. The integrated air supply equipment comprises a plurality of air collecting pipes which are fixedly connected to one end of a supporting plate and connected in a matched mode, and the supporting plate is connected with flow meters corresponding to air outlets working in the air collecting pipes in number. Each air outlet is provided with a pressure reducing valve, and each pressure reducing valve is connected with the corresponding flow meter through a respective air conveying pipe. Compared with a traditional distributed gas supply system, the number of pipeline connection nodes is reduced, the gas leakage risk is reduced, and meanwhile standardized production and on-site rapid installation of equipment are facilitated.

The application discloses a kind of based on variable wall thickness control's beer bottle lightweight pressure blow forming method, through material drop accurate supply, initial mould variable pressure pressing, bottle blank vacuum shaping, mould transfer preheating, three-stage variable pressure blow forming, partition cooling solidification, annealing stabilization, eight major steps of on-line detection, in combination with variable-diameter punch, partition temperature control, dynamic punch compensation, segmented vacuum control, realize the differentiation of beer bottle mouth, shoulder, body, bottom wall thickness Precision distribution;The weight of the 500ml specification beer bottle prepared is only 260-280g, the weight reduction is 15%-23%, the bottle body thickness ratio is less than or equal to 1.8:1, and the internal pressure strength is greater than or equal to 1.6MPa, the impact strength is greater than or equal to 1.0J, the internal stress is less than or equal to 2 levels, solve the contradiction between weight reduction and strength, at the same time reduce the defective rate to 2%-3%, save raw materials and energy consumption, adapt to the demand of beer bottle large-scale green production.

The present invention relates to a device (40) for adjusting the tension of a roughing base support (32), comprising a cam mechanism having a cam on which the roughing base support (32) is able to bear during its assembly, and an actuation mechanism configured to move the cam to at least two positions, the cam mechanism being configured to position the roughing base support (32) bearing on said cam at two different heights, depending on the position of said cam. The invention also relates to an intermediate support (35) having such an adjustment device (40).

The invention provides a light-weight double-section blowing type forming process for a glass bottle, belongs to the field of glass product processing, and solves the problems of low forming production efficiency, insufficient precision, poor system performance and the like of the existing glass bottle. Comprising the following steps: S1, preparing and melting raw materials; s2, feeding and prototype forming; s3, shaping and strengthening; s4, annealing treatment; and S5, carrying out online detection and sorting. According to the invention, through double-section pressure blowing and addition of a special reinforcing agent, the difficult problem of consideration of light weight and strength is successfully solved, dynamic initial blowing pressure control based on viscosity and servo precise control of mold movement are adopted, and an online laser thickness measurement and intelligent feedback system is combined, so that process parameters can be automatically and finely adjusted, and the consistency and qualified rate of products are improved; each core module is provided with an electric three-dimensional positioning mechanism, so that quick and accurate centering and cooperative adjustment of the mold are realized; a whole-process quality monitoring system from forming to delivery is integrated, the mechanical reliability and durability of each delivery product are ensured, and defective products are avoided.

The utility model relates to bottle blowing machine technical field discloses the bottle blowing machine for glass bottle production for cosmetics, including work table, the upside fixedly connected with the fixing frame of work table, the inside both sides fixed mounting of fixing frame have the pneumatic cylinder, the telescopic end fixedly connected with mounting seat of pneumatic cylinder, the inside of mounting seat is provided with mould, the upside of mould is provided with blow head, be provided with mounting assembly between mounting seat and mould, the inner bottom fixed mounting of work table has electric slide rail, the upside sliding connection of electric slide rail has electric sliding block, the upside fixedly connected with electric push rod of electric sliding block. In the utility model, through the combination of soft support frame cooperation electric slide rail, electric push rod, can automatically adjust the support position according to the bottle height, avoid finished product collision damage, cooling box and cooling fan work in coordination, dustproof filtration is combined, ensure mould high -efficient cooling.

The invention relates to the technical field of design and manufacturing of micro-hemispherical resonator gyroscopes, in particular to a position calibration method of a blast burner for high-temperature blowing forming of a micro-hemispherical resonator, which comprises the following steps of: establishing a linear mapping model between an alignment error and a height difference; three times of high-temperature blowing experiments are completed, and the plane coordinates of the blowtorch and the corresponding harmonic oscillator height difference measurement value in each experiment are recorded respectively; a residual target function is constructed on the basis of experimental data, and optimal coordinates of the blowtorch enabling the theoretical height difference to be minimum are optimized, solved and calculated in a back-stepping mode through a genetic algorithm; and taking the obtained optimal coordinate as a new blowtorch pose to carry out a next blowing experiment, and after new height difference data is obtained, combining historical data to repeatedly execute genetic algorithm solution and iteratively update the blowtorch position until the height difference meets the process tolerance requirement. The method aims at evaluating and compensating the alignment error of the blowtorch and the mold in real time in the high-temperature blowing process so as to restrain the first-order harmonic error in the height direction of the harmonic oscillator and improve the geometric consistency of forming.

The invention relates to a method and a blower to blow and cool glass containers (1). The method comprises introducing a gob of molten glass in a preparatory mold, deforming the gob of glass to obtain a preform, transferring the preform to a blowing mold (220), placing a blower (300) above the blowing mold (220) and introducing air inside the preform to obtain a glass container (1) with a final shape, introducing liquid water with a total level of solids less than or equal to 25 ppm in the glass container (1) to cool same, withdrawing the blower (300) by separating it from the blowing mold (220), and removing the glass container (1) from the blowing mold (220). The invention also relates to a glass container forming machine comprising the blower (300).

The invention relates to the technical field of glass production, and discloses a multi-shaft linkage type glass blowing device which comprises a workbench, a rack, an air cylinder, an air outlet pipe, an air adjusting structure and an impurity removing structure, the air outlet pipe is driven by the air cylinder to be tightly attached to a mold port, air flow can be prevented from leaking from a gap of the port in the blowing process, and the air outlet pipe is driven by the air cylinder to be tightly attached to the mold port. The high-pressure air flow can fully act on the glass liquid; the air adjusting structure realizes lifting of the sleeve along the long rod through cooperative transmission of a motor, a gear and a screw rod, the bottom accumulation effect of molten glass caused by gravity is actively resisted in combination with a bottom-to-top movement track of the sleeve and an air hole blowing mode, and the problem that the wall thickness is not uniform due to too thick bottom and too thin top in traditional fixed position blowing is thoroughly solved; through meshing transmission of the planetary gear and the gear ring, the impurity removal brush is driven to rotate around the sleeve and rotate, and is matched with the inner connecting brush to synchronously clean the inner wall of the sleeve, and impurities such as glass residues and deposited carbon remaining on the inner wall and the outer wall can be comprehensively removed.

A method of forming a glass container includes providing a glass parison having a tubular wall that includes an inside surface, which defines an interior parison cavity open at one axial end of the tubular wall, and an outside surface. The tubular wall includes an expandable blow portion that has a forming viscosity between 107.5 Pa·s and 105.5 Pa·s and is also in an isoviscous state. The glass parison is blow molded into a glass container by introducing a compressed gas into the interior parison cavity to thereby cause the expandable blow portion of the tubular wall to expand outwardly into a portion of a wall that defines the glass container.

The utility model discloses a stamping internal cooler for manufacturing a glass container, which comprises a connecting part and an air pipe, the air pipe communicated with the connecting part is arranged on the upper surface of the connecting part, a plurality of air holes are arranged on the air pipe, two sides of the upper part of the air pipe are provided with through notches, and the notches and the top surface of the air pipe form a U shape. An inner air cavity of the air pipe is composed of first to sixth inner cavity parts which are sequentially connected, the first inner cavity part is connected with the connecting part and has a constant diameter, the second inner cavity part is in an expansion form that the second inner cavity part is gradually expanded from the first inner cavity part to the two sides and is connected with the third inner cavity part, the third inner cavity part is gradually expanded from the two ends to the middle, and the diameter of the fourth inner cavity part is not changed; the fifth inner cavity part is gradually expanded from the two ends to the middle, and the diameter of the sixth inner cavity part is kept stable; according to the utility model, cooling gas can be ensured to uniformly escape, the gas can be guided to flow according to a specific path, airflow turbulence is avoided, airflow pressure is stabilized, and efficient cooling is realized.

The invention belongs to the technical field of bottle-making machines, and particularly relates to a rotating disc type bottle-making machine which comprises a base, a carrier block is fixedly mounted at the top of the base, a rotating shaft is rotatably mounted at the top of the carrier block, and a driving assembly is connected to the lower side of the outer wall of the rotating shaft and used for driving the rotating shaft to rotate; the upper side of the outer wall of the rotating shaft is fixedly sleeved with a rotating disc, forming dies are fixedly installed on the four upper sides of the rotating disc, bottom die lifting devices are connected to bottom dies of the forming dies, and synchronous positive blowing main shafts are rotationally installed on the two sides of the top of the rotating disc. The four stations are arranged on the rotating disc, the forming dies are installed on the stations, the servo motor is controlled to rotate by utilizing an external industrial control computer, and therefore the rotating disc can be controlled to rotate by 90 degrees or 180 degrees, double stations and four stations can be automatically switched, rapid switching is achieved, the working efficiency is improved, and the working efficiency is improved. And by means of the arrangement of the two-mold bottle making synchronous positive blowing head and the four-mold air blowing head, the two-mold bottle making synchronous positive blowing head and the four-mold bottle making synchronous positive blowing head can be rapidly suitable for being used by two molds and four molds.

The invention belongs to the technical field of air volume adjustment, and particularly relates to a forming machine bottom die lifting device air volume adjusting assembly which comprises a top plate, the bottom of the top plate is fixedly connected with a shell, and the bottom of the shell is fixedly connected with a bottom plate. A cover plate is arranged at the position, located on the upper side of the bottom plate, of an inner cavity of the shell, a screw is arranged between the cover plate and the bottom plate, a limiting block is fixedly installed on one side of the top of the bottom plate, the inner end of the screw is rotationally connected with the limiting block, the outer wall of the screw is sleeved with an air door adjusting plate, and an air inlet is formed in the bottom plate and penetrates through the cover plate. The bottom of the top plate is provided with a plugging assembly corresponding to the air inlet. The air volume adjusting insertion plate can be driven to move by rotating the screw rod under the condition of thread driving, so that the positions of the air volume adjusting insertion plate and the air inlet are adjusted, the air inlet volume can be adjusted, adjustment can be performed by referring to the dial during adjustment, and the adjustment accuracy can be improved.

The application discloses an energy-saving optical glass circulating production equipment and process, belongs to the optical glass circulating production technical field, and the bidirectional screw rod is rotationally connected to the inner wall of the machine body, the vertical frame is movably connected to the outer circumferential surface of the bidirectional screw rod, the number of the vertical frames is two, and the vertical frames are symmetrically distributed on the outer circumferential surface of the bidirectional screw rod, the inside of the vertical frame is provided with a movable key, and the movable key is located in the spiral groove of the outer circumferential surface of the bidirectional screw rod, and the limiting die bolt is fixedly connected to the outer wall of the vertical frame. The blowing ring port rotation can make the molten glass liquid that is dipped more evenly distributed outside the blowing ring port, so that the optical performance and quality of the blown glassware are greatly improved.

Improved glass receptacle, automated production method and manufacturing tooling thereof, the glass receptacle comprising a finished receptacle body (11) and a receptacle mouth region (30) including a receptacle mouth (31), a neck ring (32) and finished thread ridges (22) therearound; wherein the finished thread ridges (22) are placed between the neck ring (32) and the finished receptacle body (11), said receptacle being produced by a preform (1) with starting thread ridges formed in a blank mold (40) with starting thread grooves, and later transferred and finished by a blow-molding operation in a blow mold (50) with finishing thread grooves producing a finished receptacle with finished thread ridges.

An energy-saving blow molding device for glassware processing, comprising a molding die, a driver and a blowing cylinder. The inside of the molding die is provided with multiple groups of air guide cavities surrounding the outside of the die cavity, and each group of air guide cavities is independently communicated with an external air supply device. The air supply device is configured to introduce air flows of different temperatures into different groups of air guide cavities to adjust the temperature of different regions in the die cavity. Different temperature air flows can be introduced into each group of air guide cavities to adjust the flow resistance of the glass in different regions in the die cavity, so as to promote the uniform distribution of the glass during the glass blowing process by controlling the glass extension ability. The blowing cylinder comprises a blowing guide pipe communicated with the external air supply device. The blowing guide pipe is telescopically arranged in the die cavity and can adjust the position of the air outlet of the blowing guide pipe in the die cavity. The blowing pipe can provide air flows of different directions at multiple positions inside the glass to provide pressure to different positions inside the glass, so as to promote the uniform extension of the glass in each region.

The invention relates to the technical field of glass product forming and manufacturing, and discloses glass product precision thermal control forming equipment which comprises a forming main machine and is characterized by further comprising the following systems integrated on the forming main machine: an infrared material drop temperature control system arranged on a conveying path of glass material drops and used for controlling the temperature of the glass material drops; the non-contact radiation heating device is used for performing non-contact radiation heating and temperature homogenization on material drops; according to the embedded mold active temperature control system, a heat exchange element network is embedded in a mold, and the heat exchange element network is connected to an external program temperature control device and used for conducting independent temperature regulation and control on different areas of the mold. According to the invention, an infrared material drop precise temperature control system, an embedded mold active temperature control system and a whole-process atmosphere protection system are integrated, and a corresponding precise preparation process is matched, so that the difficulty in forming the large-size special-shaped amber glass bottle is systematically overcome, and an effective technical scheme is provided for producing a high-quality special glass packaging container.

The invention is applied to the technical field of glass bottle making, and particularly discloses an energy-saving glass bottle making gas trapping mechanism which comprises a lower mounting seat, a supporting column is fixedly mounted on the upper surface of the lower mounting seat, an upper mounting seat is fixedly mounted on the outer surface of the supporting column, and a circular mounting hole is formed in the surface of the upper mounting seat in a penetrating mode. According to the energy-saving air flapping mechanism for glass bottle making, the two air flapping cylinders are arranged, and preheating structures are arranged on the rotating paths of the two air flapping cylinders correspondingly, so that the preheating process of the air flapping cylinders can be completed in the process of switching stations to wait for feeding, and when the air flapping cylinders rotate to the positions of the side plates to wait for glass feeding, the preheating structures are arranged on the rotating paths of the two air flapping cylinders correspondingly; the heating sheets on the surfaces of the side plates can preheat air flow on the surface of the air inflation cylinder and in the air inflation cylinder, extra production time does not need to be occupied, the preheated air inflation cylinder can avoid thermal shock generated by contact of low-temperature air flow and a high-temperature glass blank, and hidden dangers of cracking and deformation of glass products are reduced.

A method of forming a glass container (44) includes providing a glass parison (10) having a tubular wall (12) that includes an inside surface (14), which defines an interior parison cavity (20) open at one axial end (22) of the tubular wall, and an outside surface (16). The tubular wall includes an expandable blow portion (28) that has a forming viscosity between 107.5 Pa•s and 105.5 Pa•s and is also in an isoviscous state. The glass parison is blow molded into the glass container by introducing a compressed gas into the interior parison cavity to thereby cause the expandable blow portion of the tubular wall to expand outwardly into a portion of a wall (46) that defines the glass container.

The invention relates to the technical field of glass production, and discloses a disc type positive blowing mechanism of a glass bottle making machine, the disc type positive blowing mechanism comprises a driving platform, two groups of control boxes and two groups of shaping assemblies are fixedly mounted at the upper end of the driving platform, and a blowing assembly is arranged right above each group of shaping assembly; high-pressure residual gas overflowing from a glass blank bottle opening in the blowing process is guided into the semicircular pipe on the outer side of the faying face of the forming half die through the bent pipe, gas pressure is converted into axial holding force through the inclined face wedge-caulking effect of the wedge-shaped block, splicing gaps generated due to non-uniform shrinkage of the die under the high-temperature working condition are dynamically compensated, and the forming quality is improved. In addition, when the residual air flow passes through the communicating grooves in the forming half molds, the residual air flow not only can take away the residual heat of the molds to stabilize the working temperature, but also can accelerate the discharge of air in the gaps between the glass blanks and the molds through the injection effect, so that the uniform forming of the bottle bodies is ensured, and the production efficiency is improved. And collaborative optimization of accurate positioning control, dynamic sealing compensation and efficient exhaust is achieved.

The application discloses a kind of glass container forming die blow air components, comprising: blow head, straight pipe, locating seat, guide sleeve, spring and floating sleeve, the blow head is set on guide sleeve, the bottom of the blow head is recessed and is provided with guide hole, the top of the guide sleeve is provided with annular flange extending into guide hole, the floating sleeve is from the direction of locating seat and is penetrated annular flange and extends into guide hole, the top of the floating sleeve is provided with ring piece above annular flange, the straight pipe is set in blow head, and it extends into floating sleeve downwards, the top of the floating sleeve is provided with insertion hole corresponding to straight pipe and extending downwards, the bottom of the floating sleeve is provided with cover plate, the bottom of the insertion hole is provided with blow hole and extends to the bottom surface of cover plate downwards.

The invention belongs to the technical field of glass bottle manufacturing, and particularly relates to a forming machine molding holding clamp seat which comprises a seat body, and a through hole is formed in the middle of the bottom of the seat body; the four sides of the top of the seat body are fixedly provided with holding clamp main shaft seats, holding clamp main shafts are fixedly installed in inner cavities of the holding clamp main shaft seats, and the four corners of the top of the seat body are fixedly provided with die forming switch die spline shaft seats. And the two sides of the top of the molding switch mold spline shaft seat are rotationally provided with molding switch mold spline shafts. The holding clamp main shaft seat and the molding switch mold spline shaft seat are arranged on the seat body, so that the holding clamp main shaft and the molding switch mold spline shaft can be limited, the stability of the holding clamp main shaft and the molding switch mold spline shaft when driving molds on the two sides to move is improved, and the molding accuracy is improved; by arranging the two-mold bottle-making forward blowing main shaft limiting column, the two-mold bottle-making forward blowing main shaft can be limited.

The present invention relates to a device (40) for adjusting the tension of a roughing base support (32), comprising a cam mechanism having a cam on which the roughing base support (32) is able to bear during its assembly, and an actuation mechanism configured to move the cam to at least two positions, the cam mechanism being configured to position the roughing base support (32) bearing on said cam at two different heights, depending on the position of said cam. The invention also relates to an intermediate support (35) having such an adjustment device (40). (See Figure 10 for abbreviations.)