Automatic machines for the binding of groups of sheets are widely known.

These machines comprise one or more pneumatic clamps in which the sheets to be bound are inserted and which transports the group of sheets along the whole binding sequence. They also comprise a vibrating plane that aligns and a miller that trims the group of sheets to be bound, glue rollers and blades that spread the glue on the sheets, a casing-in device that positions each cover on the folding machine and a cover-pressing mechanism that presses the cover on to the group of sheets.

The bookbinding machines composed as described above present a series of characteristics that slow down production and/or require the performance of manual operations.

The pneumatic clamp that transports the group of sheets is opened and closed mechanically and/or pneumatically by the mechanisms of the machine, depending on the position of the sheets along their route. In case of jamming of the mechanisms, or if the sheets must be removed for any other reason, it is necessary to force the opening of the clamp manually and also to move forward

or backward the whole chain that transports the clamp, with the risk of being injured and/or of making pieces of sheets or covers fall into the mechanisms of the machine.

The sheet levelling tables are positioned on various cams, in such a way as to permit their vertical adjustment depending on the edge that must be successively trimmed by the miller/millers. This system with cams for the adjustment of the levelling table does not ensure a correct horizontal adjustment of the table itself, and consequently the sheets result to be inclined with respect to the millers and also to the cover that is successively applied.

The glue rollers and blades are partially immersed in a glue tank. Since different types of glue are used, it must be possible to remove the tank, the rollers and the blades either to change and to clean them. At present the tank, rollers and blades are positioned on a trolley to constitute a single unit, therefore there is a trolley with rollers and blades for any type of glue, which represents a considerable encumbrance and a considerable weight to be handled.

In order to eliminate all the drawbacks mentioned above, an innovative machine for the continuous binding of books and booklets has been designed and implemented.

The new bookbinding machine comprises in its main parts a series of innovative pneumatic clamps mounted on a chain, a new levelling device, a miller, an innovative glue spreading unit and a cover-pressing mechanism.

The pneumatic clamps are adjustable and can hold the groups of sheets independently of their volume, up to a given maximum thickness. These

pneumatic clamps are mounted on a chain that is generally ring-shaped and runs along the stations of the bookbinding process until the clamps return to the starting area where the groups of sheets are loaded.

The pneumatic clamps have the function to transport each group of sheets along the various processing stations and to prevent the single sheets from moving with respect to one another.

These pneumatic clamps comprise two vertical walls between which the groups of sheets are positioned. The opening and closing of the two parts of the clamp takes place by means of mechanisms that are present partly on the clamp and partly on the fixed structure of the machine. Depending on what section of the chain is being covered, the clamp is automatically opened, closed, or held in one of these two positions.

A second mechanism provided with an elastic element and an operating lever is applied to the clamp opening and closing mechanism. Said second mechanism allows the two parts of the clamp to be opened at any moment: the elastic element provides for keeping the two parts in the position controlled by the clamp opening and closing mechanisms of the new machine, while the lever counteracts the action of the elastic element and opens the two parts of the clamp as much as necessary to permit the release of the group of sheets held between them.

Said second clamp opening mechanism allows the operator to remove the sheets that may be positioned incorrectly or jammed in the clamp.

The sheet levelling device comprises two horizontal plates parallel to each other, the lower of which is permanently fixed to the machine, while the upper one supports the horizontal levelling table provided with vibrators.

The two horizontal parallel plates are joined by means of connecting elements.

One of these connecting elements is provided with a protrusion positioned beside the lower plate and provided with a round hole. An eccentric screw hinged to the lower horizontal plate is inserted in said hole. The rotation of the eccentric screw causes the rotation of the corresponding connection element and consequently the lifting or lowering of the upper horizontal plate. Since the two plates are joined by the connecting elements, the lifting or lowering of one of them causes the corresponding lifting or lowering of the others, and consequently the upper horizontal plate is lifted or lowered while remaining parallel to itself.

As a consequence of the above, also the horizontal levelling table is lifted and lowered while remaining parallel to itself, always in horizontal position.

In this way, the sheets levelled by the levelling device mentioned above are always positioned correctly for the successive millers that will operate according to the thickness to be cut.

The glue spreading unit comprises two complementary parts, one of which is applied to the structure of the machine, while the other is interchangeable.

The part of the glue spreading unit applied to the structure of the machine comprises a table or support hinged to said structure, in such a way as to rotate from an operating position beside the new bookbinding machine to a

maintenance position in which the table or support is facing away from the bookbinding machine.

A mechanical coupling for the transmission of motion is provided on the structure of the bookbinding machine and on the rotary table or support; when the rotary table or support is placed in operating position beside the structure of the machine, the mechanical coupling for the transmission of motion provides for transmitting motion to the components of the glue spreading unit.

Other connections without transmission of motion provide for centering the table or support in the correct position on the bookbinding machine.

The interchangeable part of the glue spreading unit substantially comprises a tank provided with glue rollers and blades. The rollers partially protrude from the upper edge of the tank, since they take the glue present inside the tank with their lower side and spread it on the sheets with their upper side. The blades provide for adjusting the quantity of glue that the rollers deposit on the sheets.

The second interchangeable part is connected to the first rotary part by means of either hooks/joints that ensure its correct position and of mechanical couplings that transmit motion from the bookbinding machine to the rollers.

By rotating the glue spreading unit it is possible to comfortably remove or service the tank-rollers-blades assembly and it is also possible to replace the tank-rollers-blades assembly specifically used for a type of glue with a different assembly specifically used for another type of glue and if necessary provided with heating elements.

Even the simple cleaning of tank, rollers and blades is much easier, since they are light and not cumbersome.

The following is just an example among many of a practical application of the invention in question, illustrated in the attached drawings, wherein: Figure 1 is a side view of the new bookbinding machine, in which it is possible to observe the chain with the clamps (M), the sheet levelling device (P) and the glue spreading unit (S).

Figures 2a, 2b and 2c are three views, a front view, a side view and a plan view, respectively, of a clamp (M). In these figures it is possible to observe the two vertical walls (Ml, M2), of which the first one (M1) is transported by the chain and the second (M2) is connected to the first one (M1) by means of an opening and closing mechanism (M3). An easy-to-reach lever (M4) makes it possible to release the second wall (M12) from the opening and closing mechanism (M3).

Figures 3a and 3b show the sheet levelling device (P) comprising two parallel horizontal plates (PI, P2), the lower of which (Pl) is permanently fixed to the machine, while the upper one (P2) supports the horizontal levelling table (P3) equipped with vibrators (P4). The two parallel horizontal plates (PI, P2) are joined by connecting elements (P5), one of which is provided with a side protrusion (P51) with a hole (P511). An eccentric screw (P6) inserted in said hole (P511) makes it possible to adjust the inclination of the connecting element (P5) and consequently the vertical position of the second horizontal plate (P2).

Figures 4a, 4b and 4c are three views of the glue spreading unit, more precisely a front view and two plan views in closed and open position, respectively.

The glue spreading unit (S) comprises two complementary parts, one of which (Sl) is fixed to the structure of the machine (N), while the other (S2) is interchangeable.

The part of the glue spreading unit (S1) applied to the structure of the machine (N) comprises a table or support hinged to said structure of the machine (N) in such a way as to rotate from an operating position beside the new machine (N) (Fig. 4b) to a maintenance position (Fig. 4c) in which the table or support is facing away from the bookbinding machine (N).

A mechanical coupling for the transmission of motion (S12) is provided on the structure of the bookbinding machine (N) and on the rotary table or support (Sl) ; when the rotary table or support (S1) is placed in operating position beside the structure of the machine (N), the mechanical coupling (S12) for the transmission of motion provides for transmitting motion to the components of the glue spreading unit (S).

Other connections (S3) without transmission of motion provide for centering the table or support (S1) in the correct position on the bookbinding machine (N).

The interchangeable part (S2) of the glue spreading unit (S) substantially comprises a tank (S21) provided with rollers (S22) and blades (S23). The rollers (S22) partially protrude from the upper edge of the tank (S21), since they take the glue present inside the tank (S21) with their lower side and spread it on the

sheets with their upper side. The blades (S23) provide for adjusting the quantity of glue that the rollers (S22) deposit on the sheets.

The second interchangeable part (S2) is connected to the first rotary part (Sl) by means of either hooks/joints (Sa) that ensure its correct position and of mechanical couplings (Sb) that transmit motion from the bookbinding machine (N) to the rollers (S22).

Therefore, with reference to the above description and to the enclosed drawings, the following claims are put forth.