Patent Description:
Sandwich panels for heat insulation are surface structures mainly consisting of an intermediate layer of expanded polyurethane coated externally by stiff or flexible protective and coating surfaces; these external surfaces being formed by sheets unwound from reels and consisting of paper, aluminium, glass fibre composites, sheet metal or the like.

Today, sandwich panels are widely used in the building field because of the excellent thermal and acoustic insulating properties with which they are provided.

Foamed sandwich panels are manufactured continuously on production lines along which different processing stations are present.

In particular, when the continuous panel is formed, it has to be processed by one of these stations that is dedicated to the transverse cutting of the panel so as to divide the panel into segments of determined length, a delicate task in which optimization and the correct compromise between cutting speed, cutting accuracy and the speed of the production line have to be found.

The cutting operation is performed by a fly cutting apparatus so as not to interfere with forming of the panel by continuous foaming that is the main plant process, optimizing and maximizing productivity; nevertheless, the apparatuses that are known today enable a maximum foaming line speed of about <NUM>/min to be achieved combined with cutting precision that is not greater than about <NUM> and at a cutting speed that is not very high, with a resulting unsatisfactory foaming speed (a cutting speed that is not high limits the minimum panel length that can be produced) and a panel quality affected by great waste generation.

The fly cutting apparatuses used today do not enable satisfactory cutting precision to be achieved that meet currently requested precision specifications; further, owing to the wear to the control members in continuous alternating movement, maintenance tasks are necessary that often entail long plant downtime.

Apparatuses for cutting panels are known from documents <CIT>, <CIT>, <CIT>, <CIT> and <CIT>.

<CIT> discloses a fly cutting apparatus for cutting panels obtained by continuous foaming, comprising a flat advancement and support structure suitable for supporting a panel and having a longitudinal axis along which said panel intended to be cut advances, a carriage for cutting filaments which also carries a holding device.

<CIT> discloses a device for cutting foam panels which has a portal structure with a clamping unit actuated by a linear motor. It is not a flying cutter. <CIT> discloses a cutting apparatus suitable for cutting panels, comprising a flat support structure (tables) suitable for supporting a panel; a portal structure (gantry) with a movable crossbar movable along said longitudinal axis; a cutting unit suitable for cutting said that is movable along a transverse axis, which is transverse and perpendicular to said longitudinal axis, said cutting unit comprising a motorized cutting element (toolhead) that is movable along an engagement/exclusion axis to penetrate or disengage from the section or thickness of said panel; a tightening pressing unit (hold-down assemblies), suitable for exerting on said panel a grasping and stabilizing pressure along a tightening axis during cutting. It is not a flying cutter, the portal structure cutting alternatively in one of three tables.

<CIT> discloses a cutting apparatus suitable for cutting panels, comprising a flat support structure suitable for supporting a panel; a portal structure with a movable crossbar movable along said longitudinal axis and driven by linear motors; a cutting unit suitable for cutting said that is movable along a transverse axis, which is transverse and perpendicular to said longitudinal axis, said cutting unit comprising a motorized cutting element that is movable along an engagement/exclusion axis to penetrate or disengage from the section or thickness of said panel. It is not a flying cutter.

<CIT> discloses a fly cutting apparatus suitable for cutting panels obtained by continuous foaming, comprising a flat advancement and support structure suitable for supporting a panel and having a longitudinal axis along which said panel intended to be cut advances; - a trolley movable along said longitudinal axis, to follow said panel and supporting: - a cutting unit suitable for cutting said panel that is movable along a transverse axis, which is transverse and perpendicular to said longitudinal axis, said cutting unit comprising a motorized cutting, a clamp unit, suitable for exerting on said panel a grasping and stabilizing pressure along a tightening axis during cutting, said apparatus further comprising a control unit configured to control in an independent and combined manner the kinematic parameters of said cutting unit, wherein said control unit is configured to control the kinematic parameters of said cutting unit along said transverse axis and to control, in a synchronized manner, the kinematic parameters of said trolley along said longitudinal axis, motor means being provided to drive said cutting unit and said movable crosspiece.

In the light of what has been set out above, there is ample room for improvement for current fly cutting apparatuses for panels.

One object of the present invention is to improve current fly cutting apparatuses.

In particular, it is desired to provide an apparatus that requires minimum and rapid maintenance interventions and is able to ensure high combined productivity.

Another object of the present invention is to provide a fly cutting apparatus that enables the production speed of the foaming line to be maximized.

A further object of the present invention is to propose a fly cutting apparatus provided with great cutting precision and speed.

An additional object of the present invention is to provide a fly cutting apparatus that is able to minimize drastically the waste produced during cutting operations and is able to permit rapid and effective removal of the waste and residue arising from cutting.

Still another object of the present invention is to provide a fly cutting apparatus provided with a simplified and harmonized structural configuration benefiting mechanical reliability, configured so as to reduce mechanical vibrations and that has a reduced number of mechanical components subject to wear.

A further object of the present invention is to reduce the wear and vibrations produced during cutting.

The objects listed above and yet others are achieved by a fly cutting apparatus according to what is defined in the attached claims.

The invention can be better understood with reference to the enclosed drawings that illustrate one embodiment thereof by way of non-limiting example, in which:.

The general features of the present invention will be illustrated below by the embodiment provided by way of non-limiting example of the attached figures.

With reference to the attached figures, a fly cutting apparatus <NUM> is disclosed below for cutting the panels transversely, which is intended to be installed on a panel production line P, in particular on a panel production line obtained by continuous foaming.

With reference to <FIG>, <FIG>, the fly cutting apparatus <NUM> for cutting panels comprises a flat advancement and support structure A for supporting a panel P, intended to be cut, which advances along a longitudinal axis X of the rest plane A. The apparatus <NUM> has, further, a portal structure with a movable crossbar <NUM>, which can move along the longitudinal axis X and is supported by two longitudinal pads <NUM>,<NUM> that are slidable along longitudinal sliding guide elements <NUM>,54bis with guides parallel to the transverse axis X to follow the movement of the panel P.

As shown in <FIG>, a cutting unit <NUM> is arranged and supported slidably along the transverse axis Y on the movable crossbar <NUM>, the cutting unit <NUM> being suitable for cutting the panel P along a transverse axis Y transverse and perpendicular to the longitudinal axis X.

With reference to <FIG>, a tightening pressing unit <NUM> is further connected by uprights <NUM>,<NUM> to the movable crossbar <NUM> to exert on the panel P a grasping and stabilizing pressure along a tightening axis Z1 during cutting.

As shown in <FIG>, the cutting unit <NUM> is associated with an extraction hood <NUM> suitable for sucking material like chips or other residues in the form of granules or dust produced during cutting and is movable in a controlled manner along a suction axis Z2 so as to approach or move away from the upper surface of the panel P. The cutting unit <NUM> includes a motorized cutting element <NUM> that is movable in a controlled manner along an engagement/exclusion axis Z to penetrate or disengage from the section or thickness h of the panel P.

The command and control, in an independent and combined manner, of kinematic parameters of the cutting unit <NUM> is assigned to a control unit UC (<FIG> and <FIG>). In particular, the control unit UC is configured to control in an independent and synchronized manner both the kinematic parameters of the cutting unit <NUM> along the transverse axis Y and the kinematic parameters of the movable crossbar <NUM> along the longitudinal axis X, and the tightening pressing unit <NUM> (<FIG>).

The control unit UC, as schematized in <FIG>, is configured to control in an independent and synchronized manner the kinematic parameters of the motorized cutting element <NUM> along the engagement/exclusion axis Z, so as to counteract and damp possible vibration triggering phenomena, thus containing the stresses to which the various members of the apparatus <NUM> could be subjected.

The control unit UC is configured to control in an independent and synchronized manner also the movement and the position of the extraction hood <NUM> so as to maximize the capacity thereof to capture and suck cutting residues (<FIG>).

With reference to <FIG> and <FIG>, the movement of the extraction hood <NUM> along the suction axis Z2 is performed and controlled by a suction electric cylinder <NUM> drivable by linear movement means controlled by an electric motor; in particular the suction electric cylinder <NUM> is drivable by a suction electric motor of brushless type <NUM> provided with a respective absolute encoder and drivable in a dedicated manner. In another embodiment that is not shown, the movement of the extraction hood <NUM> along the suction axis Z2 is performed and controlled by a pneumatic or hydraulic aspiration cylinder.

The flat advancement and support structure A is defined by oblong support and advancement elements <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM> and by a horizontal plate <NUM> divided into two parallel abutting sections, as shown in <FIG>. Further, as visible in <FIG>,<FIG>,<FIG> and <FIG>, the apparatus <NUM> is provided with lateral directing elements <NUM>,<NUM>,<NUM>,<NUM> suitable for ensuring sliding of the panel P during the cutting operation, by centring the panel P along the longitudinal axis X and preventing deflection thereof during a cut of limited length.

In particular, the abutting horizontal plate <NUM> is suitable for supportingly receiving the panel P, and is provided with a slit <NUM> that is suitable for making the excess cutting element <NUM> penetrate and slide below the lower surface of the panel P during transverse cutting of the panel P. In addition, as cutting of the panel P is performed at the slit <NUM> of the abutting horizontal plate <NUM>, suction elements <NUM>,<NUM> are provided below the slit of the abutting horizontal plate <NUM> to suck the removed material produced during cutting.

Again with reference to <FIG>, the pressing unit <NUM> comprises a pressure crossbar element <NUM> that is movable along the uprights <NUM>,<NUM> with respect to the horizontal plate <NUM> according to the tightening axis Z1, by which the pressing unit <NUM> presses the panel P against the abutting horizontal plate <NUM>, exerting the grasping and stabilizing pressure. In detail, the pressure along the tightening axis Z <NUM> is exerted by tightening electric cylinders <NUM>,<NUM> drivable by motor means; in particular the tightening electric cylinders <NUM>,<NUM> are drivable by tightening motors of brushless type <NUM>,<NUM> (<FIG>) that are fitted to the uprights <NUM>,<NUM> in a parallel configuration and commanded to move synchronized by the control unit UC, each of which is drivable independently and provided with a respective absolute encoder. Each of the tightening electric cylinders <NUM>,<NUM> is also provided with a control means to ascertain the contact of a respective part of the pressure crossbar element <NUM> with the panel P by active magnetic traction and zero speed traction signals or by pressure detection by means of a load cell.

In a further embodiment that is not shown, the pressure along the tightening axis Z1 is exerted by a servomotor with mechanical transmission and synchronized by mechanical connecting means.

The servomotor with mechanical transmission, for example, is of the rack-and-pinion type and the mechanical connecting means is, for example, of the rack-and-pinion type or of the belt-screws type.

The electrically controlled transmission means disclosed above enables the movement of the pressing unit to be controlled with a disengagement height that is settable, for example by <NUM>, so as to make the extension and the movement time very contained and therefore much more efficient than pneumatically or hydraulically controlled pressure means.

As visible in <FIG>, the cutting element <NUM> is supported by an engagement/exclusion carriage <NUM> that is fitted slidably along the engagement/exclusion axis Z on a transverse stroke carriage 20bis, shaped as a plate.

In particular, the movement of the engagement/exclusion carriage <NUM> along the engagement/exclusion axis Z is performed by an engagement/exclusion electric cylinder <NUM> drivable by motor means arranged on the transverse stroke carriage 20bis; still more in particular, the engagement/exclusion electric cylinder <NUM> is drivable by an engagement/exclusion motor of brushless type <NUM>.

The engagement/exclusion carriage <NUM>, in detail, is provided with dedicated pads (not shown) for sliding along a respective sliding engagement/exclusion guides element <NUM>, with guides parallel to the engagement/exclusion axis Z, arranged on the transverse stroke carriage 20bis.

Further, the engagement/exclusion carriage <NUM> has guides <NUM>, parallel to the engagement/exclusion axis Z, for positioning according to the suction axis Z2 of the extraction hood <NUM>. In detail, the extraction hood <NUM> is provided with appropriate suction pads <NUM>,<NUM> that couple slidingly with the aforesaid guides <NUM> to enable the extraction hood <NUM> to translate along the suction axis Z2 with respect to the engagement/exclusion carriage <NUM> and then with respect to the cutting element <NUM>.

The engagement/exclusion motor of brushless type <NUM> is driven by the control unit UC independently and is provided with a respective absolute encoder to control position and movement.

The engagement/exclusion axis Z is so oriented orthogonally to the support and advancement plane A that the cutting element <NUM> is movable and positionable through the thickness h of the panel P.

In one alternative embodiment that is not shown, the movement of the cutting element <NUM> along the engagement/exclusion axis Z is performed by a pneumatic or hydraulic cylinder for controlling the engagement/exclusion movement coupled with a respective sliding engagement/exclusion guides element <NUM>, parallel to the engagement/exclusion axis Z and arranged on the transverse stroke carriage 20bis.

The cutting element <NUM> can be, as shown in <FIG>, a toothed circular blade <NUM> connected removably to the drive shaft of the cutting unit <NUM> to be able to be replaced rapidly so as to adapt the diameter and/or the toothing features thereof to the thickness h of the panel P. Further, as visible in <FIG> and <FIG>, the cutting unit <NUM> comprises a protection and suction unit <NUM> suitable for housing the cutting element <NUM>. In particular, the protection and suction unit <NUM> includes the extraction hood <NUM>. By controlling the position of the extraction hood <NUM> along the suction axis Z2, the cutting element <NUM> is made to protrude from the protection and suction unit <NUM> only by the quantity or circular segment necessary for obtaining the cutting depth appropriate for performing the operation of cutting the panel P. If the cutting element <NUM> consists of a circular blade <NUM>, as shown in <FIG>, the protruding circular segment is also chosen in function of the diameter of the circular blade <NUM>.

The protection and suction unit <NUM> comprises an openable access wall <NUM> to enable the aforesaid replacement of the circular blade <NUM> (or another removably connected cutting element <NUM>). The access wall <NUM>, for example, can be made openable owing to the use of a hinge and the relative opening device or knob provided with safety.

In the event of an interruption to the electricity supply or emergency stop, the cutting element <NUM> has to be disengaged from the panel P by lifting the panel P along the engagement/exclusion axis Z; the disengagement can be performed by a lifting unit (not shown) supplied by electric power taken from the engagement/exclusion linear motor of brushless type <NUM> during normal operation and accumulated in an accumulating device or by a pneumatic weight over-balancing device (not shown).

The movement of the cutting unit <NUM>, and thus of the cutting element <NUM>, along the transverse axis Y is performed, as visible in <FIG>, owing to linear motor means; in particular owing to a transverse linear motor <NUM>,<NUM>, controlled and drivable independently, and provided with a respective absolute inductive linear encoder for controlling movement and position, coupled with a respective sliding transverse guides element <NUM> with guides parallel to the transverse axis Y and arranged on the movable crossbar <NUM>; the previously introduced sliding transverse guides element <NUM>, has transverse damping elements <NUM>,<NUM> for damping the end stop of the movement of the cutting unit <NUM> along the transverse axis Y.

The transverse linear motor of brushless type <NUM>,<NUM> can be of synchronous or asynchronous type.

An active part of said transverse linear motor of brushless type <NUM>,<NUM>, provided with coil magnetic elements for inducing controlled magnetic fields that exert magnetic forces to control the movement along the transverse axis Y is installed on the transverse stroke carriage 20bis.

The aforesaid active part of the transverse linear motor of brushless type <NUM> is provided with transverse pads <NUM>,<NUM> fitted to the transverse stroke carriage 20bis for sliding along the rails of the transverse guides element <NUM>.

In particular, the active part of the transverse linear motor of brushless type <NUM> fitted to the transverse stroke carriage 20bis couples with the magnetic fields generated by a series of magnets comprised inside a transverse magnetic linear element <NUM> arranged parallel to the guides of the sliding transverse guides element <NUM> so as to permit the movement of the transverse stroke carriage 20bis, and thus of the cutting unit <NUM>, along the transverse axis Y.

With reference to <FIG>, the movement of the movable crossbar <NUM> along the longitudinal axis X is performed owing to linear motor means; in particular owing to longitudinal linear motors <NUM>,<NUM>;<NUM>,<NUM>.

With reference in particular to <FIG>, the movable crossbar <NUM> extends along a direction D, parallel to the transverse axis Y, and has distal ends E1, E2 at which active parts of longitudinal linear motors of brushless type <NUM>,<NUM> are positioned to implement the movement along the longitudinal axis X of the movable crossbar <NUM>. The aforesaid active parts of the longitudinal linear motors of brushless type <NUM>,<NUM> comprise coil magnets to generate the magnetic fields for controlling the movement along the longitudinal axis X; further, as shown in <FIG>, respective longitudinal pads <NUM>,<NUM> are provided for sliding along the guides of the longitudinal sliding guide elements <NUM>,54bis.

The active parts of the longitudinal linear motors of brushless type <NUM>,<NUM> are controlled by the control unit UC.

In detail, with reference to <FIG>, the active parts of the longitudinal linear motors of brushless type <NUM>,<NUM> couple with the magnetic fields generated by a series of magnets included inside respective longitudinal magnetic linear elements <NUM>,<NUM> arranged parallel to the guides of the longitudinal sliding guide elements <NUM>,54bis so as to enable the movable crossbar <NUM> to move along the longitudinal axis X. The longitudinal magnetic linear elements <NUM>,<NUM> are arranged and fixed on respective crosspieces <NUM>,<NUM> that are part of a frame <NUM>. The longitudinal linear motors of brushless type <NUM>,<NUM> can be synchronous or asynchronous and the magnetic linear elements <NUM>,<NUM> can have permanent magnets or magnets that are activatable with electric coils; further, the longitudinal linear motors of brushless type <NUM>,<NUM> are provided with respective absolute encoders and are drivable independently with a coordinated control that ensures the synchronism thereof.

Similarly to the sliding transverse guides element <NUM>, also the longitudinal sliding guide elements <NUM>,54bis have respective longitudinal damping elements <NUM>,<NUM>,<NUM>,<NUM> to damp the arrest of the movement of the movable crossbar <NUM> along the longitudinal axis X.

In the embodiment shown in the attached figures, the transverse axis Y is perpendicular both to the longitudinal axis X and to the engagement/exclusion axis Z, the latter being in turn orthogonal to the longitudinal axis X and also parallel to the suction axis Z2 and to the tightening axis Z1.

The apparatus <NUM>, further, has vibration sensors or accelerometers (not shown) coupled with the longitudinal axis X and with the transverse axis Y, which are configured to ascertain the correct operation of the apparatus <NUM> to detect possible faults and thus report the need for maintenance tasks.

An operating cycle of the apparatus <NUM> for cutting panels obtained by continuous foaming will be disclosed below.

First, the circular blade <NUM> is rotated at a rotation speed that is linked to various operating conditions, for example to the speed of the foaming line and to the thickness h of the panel P, but mainly depends on the diameter of the circular blade <NUM>. In this step, the movable crossbar <NUM> and the cutting unit <NUM> are stationary in a start position, and the circular blade <NUM>, the extraction hood <NUM> and the pressing unit <NUM> do not interact with the panel P.

Subsequently, a first cut is performed with a manual control that grasps the panel P with the tightening pressing unit <NUM> after automatically synchronizing the advancement speed of the movable crossbar <NUM> with the advancement speed of the panel P and then commands the transverse cut to identify the position of the subsequent cut (the distance measurement is automated) depending on the length of the panel P to be produced.

The aforesaid steps are performed only for the first operating cycle, whereas the steps that will now be disclosed are repeated for each (automated) cut performed.

At this point, the movable crossbar <NUM> is retracted in a direction opposite the direction of the movement of the panel P, and the cutting unit <NUM> is taken to an end of the crossbar <NUM>, then the movement along the longitudinal axis X of the movable crossbar <NUM> is synchronized with the speed of the panel P and the pressing unit <NUM> applies the grasping and stabilizing pressure along the tightening axis Z1 by the pressure crossbar element <NUM>; whilst the extraction hood <NUM> is brought near the panel along the suction axis Z2.

Subsequently, the circular blade <NUM> penetrates the panel P along the engagement/exclusion axis Z and the cutting unit <NUM> is moved along the transverse axis Y, with a movement that is simultaneous to the following movement along the longitudinal axis X, to perform cutting of the panel P.

After cutting is completed, the circular blade <NUM> disengages from the panel P, and both the extraction hood <NUM> and the pressure crossbar element <NUM> move away from the upper surface of the panel P.

The movement along the transverse axis Y of the cutting unit <NUM> is interrupted, the tightening pressing unit <NUM> disengaged and raised, and the cutting unit <NUM> returns to the start position; simultaneously, also the movable crossbar <NUM> returns to the start position with movement that is accelerated and opposite the movement direction of the panel P and the apparatus <NUM> is ready to perform a new cut.

Owing to the features disclosed above, the fly cutting apparatus <NUM> successfully achieves the aforesaid previously set objects.

First, using linear motors of brushless type <NUM>,<NUM>,<NUM> that are coupled with the respective magnetic linear elements <NUM>,<NUM>,<NUM> and provided with respective absolute encoders and drivable independently enables the number of sensors used to be reduced compared with prior art apparatuses, increasing the reliability of the apparatus <NUM> and simplifying the construction and maintenance thereof. Linear motors of brushless type <NUM>,<NUM>,<NUM> coupled with the respective magnetic linear elements <NUM>,<NUM>,<NUM> also enable both cutting precision to be increased because they permit dynamic positioning of the moving axes in general and in particular during the acceleration and synchronization steps with the speed of the panel P, before activating the function of the tightening pressing unit <NUM>, which other actuating systems do not achieve (precision guaranteed up to a few tenths of a millimetre), reducing waste, and the maximum cutting speed and foaming line speed (up to <NUM>/min) to produce panels that are <NUM> in length. Lastly, this solution also enables acceleration ramps to be set with management of derivative of acceleration (Jerk) during the initial and final application steps in order to damp effects due to sudden acceleration forces.

In addition, even using electric cylinders <NUM>,<NUM>,<NUM>,<NUM> drivable by respective motors of brushless type <NUM>,<NUM>,<NUM>,<NUM> provided with respective encoders that are absolute and in turn drivable independently enables the dynamic positioning precision to be increased when the axes are moving and accelerating; further, the movement actuating speeds are increased, thus reducing both implementing time and the number of sequence sensors necessary compared with those used in prior art apparatuses. Said prior art sensors are necessary to give the zero point in the use of incremental encoders so as to avoid interference during the movement sequences disclosed above, nevertheless, use thereof is critical because it increases the implementation time between one movement and the next and because, in the presence of shocks, vibrations and dirt, they often send false signals that interrupt the cutter actuation cycle.

In fact, the proposed solution enables, compared with traditional solutions with pneumatic or hydraulic cylinders, time in the order of a second to be saved during each operating cycle, permanent lubrication of this type of cylinder and the use of ramps linked to the possibility of setting the Jerk.

Lastly, by using an engagement/exclusion electric cylinder <NUM> driven by an engagement/exclusion motor of brushless type <NUM>, provided with an encoder that is absolute and drivable independently, to move the circular blade <NUM> along the engagement/exclusion axis Z enables circular blades <NUM> having a different diameter to be used, and thus the use of blades with different or reduced blades, thus reducing the thickness of the material that will be shaved, minimizing waste. In current technology in fact, the use of pneumatic pistons that reach the stroke limit forces the stroke stop to be set according to the minimum protrusion of the circular blade of smaller diameter and the use of a circular blade of greater diameter causes excessive protrusion below the panel during cutting.

From what has been exposed above, it is clear that the fly cutting apparatus <NUM> according to the invention successfully achieves the previously mentioned set objectives.

Claim 1:
Fly cutting apparatus (<NUM>) for cutting panels obtained by continuous foaming, comprising
- a flat advancement and support structure (A) suitable for supporting a panel (P) and having a longitudinal axis (X) along which said panel (P) intended to be cut advances,
- a portal structure with a movable crossbar (<NUM>) movable along said longitudinal axis (X), to follow said panel (P) and supporting
- a cutting unit (<NUM>) suitable for cutting said panel (P) that is movable along a transverse axis (Y), which is transverse and perpendicular to said longitudinal axis (X), said cutting unit (<NUM>) comprising a motorized cutting element (<NUM>) that is movable along an engagement/exclusion axis (Z) to penetrate or disengage from the section or thickness (h) of said panel (P),
- a tightening pressing unit (<NUM>) suitable for exerting on said panel (P) a grasping and stabilizing pressure along a tightening axis (Z1) during cutting,
said apparatus (<NUM>) further comprising a control unit (UC) configured to control in an independent and combined manner the kinematic parameters of said cutting unit (<NUM>), in which said control unit (UC) is configured to control the kinematic parameters of said cutting unit (<NUM>) along said transverse axis (Y) and to control, in a synchronised manner, the kinematic parameters of said movable crossbar (<NUM>) along said longitudinal axis (X), linear motor means being provided to drive said cutting unit (<NUM>) and said movable crossbar (<NUM>).