Improved pneumatic cutting device with oscillating blade for leather cutting machines

Abstract

An improved pneumatic cutting device (100) comprises a swing chamber (1); a swing piston (10) having a head (13) in the swing chamber (1) and a stem (14) connected to a cutting blade (L); a pneumatic activation system (P) for activating the swing piston (10) to swing in the swing chamber (1). The pneumatic activation system (P) comprises: a pneumatic supply source (P1); a first upper switching chamber (30) which is side-connected to the swing chamber (1) and communicates with an upper part (30A) of the swing chamber (1); a second lower switching chamber (31) which is side-connected to the swing chamber (1) and communicates with a lower part (30B) of the swing chamber (1); a first discharge hole (51) formed in a side surface (10A) of the swing chamber (1); a second discharge hole (52) formed in the side surface (10A) of the swing chamber (1); a main supply conduit (61) which communicates with the pneumatic supply source (P1); a secondary supply conduit (62) which is realized in the head (13) of the swing piston (10) and is opened at a point of a side surface (130) of the head (13) via an access hole (620) and communicates with the main supply conduit (61).

Description

Technical Field

[0001] This invention relates to the technical field of CNC automatic cutting machines, which are used to cut sheet materials such as wallets, leather pieces, animal hides, and synthetic leather.

[0002] In particular, the present invention relates to an improved pneumatic cutting device having a oscillating blade mounted on a cutting machine. Background Technology

[0003] As is known, a cutting machine includes: a working surface in which the material to be cut, such as leather pieces, synthetic leather, etc., is arranged; a frame movably mounted above the working surface; and a cutting device mounted on the frame and having a cutting blade disposed below it.

[0004] It also includes a moving tool, which is supported by and movable relative to the frame, so as to move the cutting device according to three Cartesian axes above the work plane.

[0005] In this way, the cutting blade can be positioned above the leather piece, lowered to carve the leather, and moved according to a given cutting path to cut the leather based on a predetermined and / or desired contour.

[0006] The cutting device for this purpose is pre-configured such that the cutting blade is formed to be able to swing vertically from the lower cutting position to the upper cutting position during the cutting of a leather piece, while always remaining within the thickness of the material to be cut / carved.

[0007] For this purpose, pneumatic cutting devices are currently used, wherein the cutting blade is formed to oscillate vertically by pneumatic supply.

[0008] For example, an aerodynamic cutting device with a oscillating blade is described in international patent application WO2018 / 203199 filed in the name of the same applicant.

[0009] The pneumatic cutting device (90) described in the aforementioned patent application includes a body (C) and a cutting blade (L) for cutting leather pieces stretched on a working plane.

[0010] The device is pre-set in such a way that the cutting blade (L) is pneumatically activated so that it can swing vertically to carve and cut the leather pieces.

[0011] Figures 1A to 1B The pneumatic cutting device (90) described in this document is shown in its respective front view, wherein the cutting blade (L) is indicated by two different operating configurations that can be achieved during its oscillation, namely the lower cutting position (L1) (see...). Figure 1A ) and the upper cutting position (L2) (see Figure 1B ).

[0012] The cutting device (90) has a swing chamber (1) inside the main body (C), having an upper running wall (11) and a lower running wall (12), and a swing piston (10) having a head (13) and a rod (14) (see Figure 2A and 2B ).

[0013] The swing piston (10) is arranged such that its head (13) is inserted into the swing chamber (1), between the upper running wall (11) and the lower running wall (12), and the rod (14) is connected to the cutting blade (L).

[0014] When the head (13) of the swing piston (10) abuts against the lower running wall (12) of the swing chamber (1), Figure 2A When the cutting blade (L) is in the lower cutting position (L1), and the head (13) of the swing piston (10) is adjacent to and abuts against the upper running wall (11) of the swing chamber (1), Figure 2B The cutting blade (L) is in the upper cutting position (L2).

[0015] The upper running wall (11) is arranged at a certain distance from the lower running wall (12) in the main body (C), such that when the head (13) of the swing piston (10) contacts the upper running wall (11), the cutting blade (L) reaches the upper cutting position (L2), so that the cutting blade (L) basically remains in contact with the leather piece to be cut or is slightly withdrawn, in order to ensure the continuity of the cutting operation.

[0016] The distance between the upper wall (11) and the lower wall (12) thus determines the physical extent of the swing stroke that the cutting blade (L) can make.

[0017] In order to pneumatically activate the swing of the head (13) of the swing piston (10) in the opposite swing chamber (1), and thus for the vertical swing of the cutting blade (L), the pneumatic cutting device (90) is provided with an opposite pneumatic activation system (P) communicating with the swing chamber (1).

[0018] The pneumatic cutting device (90) implemented according to the description in this patent application belonging to the applicant is capable of automatically switching the stroke of the swing piston (10), that is, there is no external valve mechanism and / or switching mechanism due to the following features: the specific construction of the rod (14) of the piston (10), the specific construction of the head (13) of the piston (10), and the specific construction of the pneumatic supply system (P).

[0019] Specific features in Figures 2A to 2B It is shown in detail in the text. Figures 2A to 2B They represent along Figure 1A and 1BSection lines II and II-II are views.

[0020] The pneumatic activation system (P) includes a pneumatic supply source (e.g., compressed air) schematically indicated by arrow (P1), an upper discharge port (S1), and a lower discharge port (S2).

[0021] The main body (C) is formed in such a way as to include a cylindrical cavity (16), and the rod (14) of the swing piston (10) is pre-configured to be able to slide alternately in the cylindrical cavity (16).

[0022] Furthermore, the rod (14) of the swing piston (10) is adapted in such a way that it slides relative to the piston in the cylindrical cavity (16) below the swing chamber (1), and thus in a position lower than the head (13):

[0023] The upper annular portion (141) and the lower annular portion (142) slide in contact with the wall of the cylindrical cavity (16);

[0024] An annular recess (140) is included between two annular portions (141, 142);

[0025] And internal conduit (17).

[0026] The rod (14) is also provided with a through hole (18), which is pre-positioned below the lower annular portion (142) along the rod (14) and allows the inner conduit (17) to contact the outside of the rod (14).

[0027] The head (13) of the swing piston (10) is provided with at least one through hole (130) arranged for placing the internal conduit (17) of the rod (14) in communication with a portion (1B) of the swing chamber (1) included between the head (13) of the swing piston (10) and the upper running wall (11) of the swing chamber (1).

[0028] The pneumatic activation system (P) is arranged and constructed as follows.

[0029] It includes:

[0030] The oscillation switching chamber (8) of the oscillating piston (10) is adapted in such a way that the oscillation areas of the two annular portions (141, 142) of the rod (14) are located below the oscillation chamber (1) and include an upper annular chamber (8A) and a lower annular chamber (8B) in part of the wall of the cylindrical cavity (16).

[0031] The main tube (81) is implemented and pre-installed in the main body (C) so as to communicate with the pneumatic supply source (P1) on one side and with a portion of the lower annular chamber (8B) of the switching chamber (8) on the other side;

[0032] A secondary conduit (82) is implemented and pre-positioned in the main body (C) to position the upper annular chamber (8A) of the switching chamber (8) in communication with the swing chamber (1) via a passage hole (83) implemented in the lower end running wall (12) of the swing chamber (1).

[0033] The upper discharge port (S1) is formed in part of the wall of the cylindrical cavity (16), below the swing chamber (1) and above the upper annular chamber (8A) of the switching chamber (8), and communicates with the outside via the first discharge conduit (92), which is also realized and pre-set in the main body (C).

[0034] In sequence, a lower discharge port (S2) is formed in a part of the wall of the cylindrical cavity (16), below the swing chamber (1) and below the lower annular chamber (8B) of the switching chamber (8), and the lower discharge port (S2) communicates with the outside via a second discharge conduit (94), which is implemented and pre-set in the main body (C).

[0035] Furthermore, the annular recess (140) of the rod (14) is sized such that the hole (18) of the rod (14) is positioned below the lower annular portion (142) relative to the annular recess (140), thereby causing the following conditions to occur as the rod (14) slides alternately in the cylindrical cavity (16):

[0036] When the annular recess (140) of rod (14) is positioned at the switching chamber (8) so that the lower annular chamber (8B) and the upper annular chamber (8A) are in communication, the hole (18) of rod (14) is positioned at the lower discharge port (S2) (see Figure 2A ), so that the main tube (81) is connected to the auxiliary tube (82) via the lower annular chamber (8B), the annular recess (140) and the upper annular chamber (8A) and thus the pneumatic supply source (P1) is connected to the portion (1A) of the swing chamber (1) included between the head (13) and the lower end running wall (12) of the swing piston (10) (see Figure 2A (Solid arrow in the text), and also includes a portion (1B) of the swing chamber (1) between the head (13) of the swing piston (10) and the upper running wall (11) communicating with the lower discharge port (S2), and then via a second discharge conduit (94) having an external side, through the hole (130) of the head (13) of the piston (10), the internal conduit (17) of the rod (14) and the hole (18) of the rod (14) (see solid arrow in the text), and the lower discharge port (S2), and then via the hole (130) of the head (13) of the piston (10), the internal conduit (17) of the rod (14) and the hole (18) of the rod (14) (see solid arrow in the text). Figure 2A (The dashed arrow in the image) allows the swing piston (10) to be pneumatically pushed upward;

[0037] And when the annular recess (140) of the second upper rod (14) is positioned at the upper discharge port (S1) and in the upper annular chamber (8A) of the switching chamber (8) communicating with the auxiliary conduit (82), the hole (18) of the rod (14) is located in the lower annular chamber (8B) of the switching chamber (8) and thus communicates with the main guide tube (81) (see Figure 2B ), so that the pneumatic power source (P1) is connected to the second part (1B) of the swing chamber (1) via the main tube (81), the hole (18) of the rod (14), the internal conduit (17) of the rod (14) and the hole (130) in the head (13) of the swing piston (10) between the upper running wall (11) and the head (13) of the swing piston (10) (see Figure 2B (Solid arrow in the image) The first part (1A) of the swing chamber (1) between the head (13) of the swing piston (10) and the lower running wall (12) communicates with the upper discharge port (S1) via the auxiliary conduit (82), the upper annular chamber (8A) of the switching chamber (8), and the annular recess (140), and then communicates with the external environment via the first discharge conduit (92) (see solid arrow in the image). Figure 2B (The dashed arrow in the image) allows the swing piston (10) to be pneumatically pushed downwards.

[0038] Due to the aforementioned special features, in the pneumatic cutting device (90) described in the aforementioned patent application belonging to the applicant, the switching of the piston's swing is activated and determined by the piston based on the position of the relative rod relative to the cylindrical cavity of the body, in particular the position of the relative annular recess relative to the switching chamber and the two discharge ports.

[0039] This pneumatic cutting device has been found to be very effective for cutting materials in sheet form (such as leather sheets and / or animal hides).

[0040] However, over time, the applicant encountered a need for more precise control over the reversal of the swinging motion of the swing piston, a step that occurs together with the impact of the swing piston head on the upper and lower running walls, and for achieving a greater swing speed by using less compressed air in the pneumatic supply source section. Summary of the Invention

[0041] Therefore, the object of the present invention is to disclose a new and improved pneumatic cutting device having a oscillating blade for a leather cutting machine, the oscillating blade being able to achieve the above-mentioned object.

[0042] Furthermore, another object of the present invention is to provide a novel and improved pneumatic cutting device that has more functions and a less complex overall structure, and thus simplifies the production process.

[0043] The above objective is achieved by an improved pneumatic cutting device with a oscillating blade for a leather cutting machine, as described in the claims. Attached Figure Description

[0044] The features of a preferred embodiment of the improved pneumatic cutting device with a oscillating blade for a leather cutting machine according to the present invention are described below with reference to the accompanying drawings, wherein:

[0045] — Figure 1A and 1B The pneumatic cutting apparatus described in the aforementioned patent application filed by the same applicant is shown in front views, with the cutting blade representing two different operating positions: Figure 1A The lower cut position (L1) and Figure 1B The upper cutting position (L2) in the middle;

[0046] — Figure 2A It is along Figure 1A An enlarged view of section II;

[0047] — Figure 2B It is along Figure 1B An enlarged view of section II-II;

[0048] — Figures 3A to 3C The improved pneumatic cutting device of the present invention is shown in its respective front view, illustrating the cutting blade in three different operating positions. Figure 3A The lower cutting position (L1) in the middle, Figure 3B The middle cutting position (LM) in the middle, and Figure 3C The upper cutting position (L2) in the middle;

[0049] — Figure 4A It is along Figure 3A Enlarged view of section III-III;

[0050] — Figure 4B It is along Figure 3B An enlarged view of section IV-IV;

[0051] Figure 4C The first preferred embodiment of the pneumatic cutting device according to the present invention is along Figure 3C An enlarged view of the cross section VV;

[0052] — Figure 5A It is along Figure 3A Enlarged view of section III-III;

[0053] — Figure 5B It is along Figure 3B An enlarged view of section IV-IV; and

[0054] — Figure 5C The second preferred embodiment of the pneumatic cutting device according to the present invention is along Figure 3C An enlarged view of the cross section VV. Detailed Implementation

[0055] Referring to the accompanying drawings, reference numeral (100) indicates the overall improved pneumatic cutting device with oscillating blade for a leather cutting machine according to the present invention.

[0056] The improved pneumatic cutting device (100) includes some of the same features as the pneumatic cutting device of the above-mentioned and said patent applications belonging to the same applicant, particularly relating to the usual general features present in pneumatic cutting devices.

[0057] Therefore, in the following description, those components of the improved pneumatic cutting device (100) of the present invention that correspond to the pneumatic cutting device of the aforementioned patent application will be represented by the same numbers and letters.

[0058] Therefore, the improved pneumatic cutting device (100) includes a body (C) and a cutting blade (L) for cutting leather pieces stretched on a working plane (the leather pieces and the working plane are not shown in the figure because they are not relevant to the present invention).

[0059] In this respect, the improved pneumatic cutting device (100) is pre-configured and constructed to be installed on, for example, a CNC cutting machine.

[0060] The device is constructed and pre-set in such a way that the cutting blade (L) is pneumatically activated so that it can swing vertically to carve and cut the leather pieces.

[0061] Figures 3A to 3C The improved pneumatic cutting device (100) of the present invention is shown in a front view, wherein the cutting blade (L) is indicated by different operating configurations that can be obtained during its oscillation, namely the lower cutting position (L1) (see...). Figure 3A ), where the cutting blade (L) traverses the entire thickness of the leather, with the middle cutting position (LM) ( Figure 3B ), wherein the cutting blade (L) is inside the thickness of the leather piece, and the upper cutting position (L2) ( Figure 3C The cutting blade (L) is located essentially on top of the leather piece.

[0062] The improved pneumatic cutting device (100) has a swing chamber (1) and a swing piston (10) inside the main body (C). The swing chamber (1) is adapted in such a way to define the upper running wall (11), the lower running wall (12) and the side surface (10A) between the upper running wall (11) and the lower running wall (12).

[0063] The oscillating piston (10) includes a head (13) and a rod (14). The oscillating piston (10) is pre-positioned relative to the body (C) such that its head (13) is inserted into the oscillating chamber (1) between the upper running wall (11) and the lower running wall (12), and the rod (14) is slidably arranged in a longitudinally positioned sliding seat (14A) in the body (C) such that the rod can be connected to the cutting blade (L) via an end opposite to the end connected to the oscillating piston (10) (see, for example, [link to cutting blade]). Figures 4A to 5C ).

[0064] The head (13) is adapted in this way to include an upper adjacent surface (131), a lower adjacent surface (132), and a side surface (130).

[0065] In order to make the head (13) swing in the swing chamber (1), the cutting device (100) includes a pneumatic activation system (P), which includes a pneumatic supply source (P1) (schematically shown by solid arrow lines).

[0066] The pneumatic activation system (P) is configured such that a first portion (1A) of a swing chamber (1) comprising between the lower adjacent surface (132) of the head (13) of the swing piston (10) and the lower running wall (12), and a second portion (1B) of a swing chamber (1) comprising between the upper adjacent surface (131) of the head (13) of the swing piston (10) and the upper running wall (11) are positioned in alternating communication with a pneumatic supply source (P1).

[0067] In this manner, by injecting compressed air, the head (13) of the swing piston (10) is pneumatically moved to the lower end running position (PL) within the swing chamber (1) (see... Figure 4A and 5A ) and the upper running position (PS) (see Figure 4C and 5C The head (13) swings between the two sides, and in the lower running position, the lower abutting surface (132) of the head (13) abuts against the lower running wall (12), wherein the upper abutting surface (131) of the head (13) abuts against the upper running wall (11), and thus the rod (14) and therefore the cutting blade (L) are in the lower cutting position (L1) of the leather piece. Figure 3A ) and the upper cut position of the leather piece (L2)( Figure 3C It swings vertically between )

[0068] The swing chamber (1) is adapted in such a way that the upper running wall (11) is arranged at a certain distance relative to the lower running wall (12) so that when the upper adjacent surface (131) of the head (13) of the swing piston (10) comes into contact with the upper running wall (11), the cutting blade (L) reaches the upper cutting position (L2) so that it remains substantially in contact with the leather piece to be cut, or is slightly withdrawn, in order to ensure the continuity of the cutting operation.

[0069] The specific features of the improved pneumatic cutting device (100) of the present invention relate to the specific construction and configuration of the pneumatic activation system (P), which is responsible for the oscillation of the head (13) of the piston (10) in the oscillation chamber (1), and therefore also responsible for the vertical oscillation of the cutting blade (L), as described in detail below.

[0070] The pneumatic activation system (P) is constructed in this manner to include:

[0071] The first upper switching chamber (30) is arranged in the main body (C) in a first position on the side of the swing chamber (1) and is directly connected to the upper part (30A) of the swing chamber (1) via a first window (11A) formed in the upper part of the side surface (10A) of the swing chamber (1).

[0072] The second lower switching chamber (31) is arranged in the main body (C) in a second position on the side of the swing chamber (1), below the first upper switching chamber (30), and is directly connected to the lower part (30B) of the swing chamber (1) via a second window (11B) formed in the lower part of the side surface (10A) of the swing chamber (1).

[0073] The discharge conduit (41) is implemented in the main body (C) and arranged in such a way as to have a first end (41A) communicating with the outside and includes a first branch conduit (411) and a second branch conduit (412). The first branch conduit (411) communicates with the upper part (30A) of the swing chamber (1) via a first discharge hole (51) formed in the side surface (10A) of the swing chamber (1), and the second branch conduit (412) communicates with the lower part (30B) of the swing chamber (1) via a second discharge hole (52) formed in the side surface (10A) of the swing chamber (1) below the first discharge hole (51).

[0074] The main supply conduit (61) is implemented in the main body (C);

[0075] A secondary supply conduit (62) is implemented within the head (13) of the swing piston (10) and opens via an access hole (620) at a point on the side surface (130) of the head (13) of the swing piston (10).

[0076] More specifically, the pneumatic supply system (P), the main supply conduit (61), and the auxiliary supply conduit (62) are arranged and constructed in this manner:

[0077] The first end (61A) of the main supply conduit (61) is connected to the pneumatic supply source (P1), and the second end (61B) of the main supply conduit (61) is connected to the auxiliary supply conduit (62).

[0078] Furthermore, the head (13) of the swing piston (1) is sized, and the auxiliary supply conduit (62) is implemented inside the head (13) such that:

[0079] When the head (13) of the oscillating piston (1) is in the lower running position (PL), and the lower abutting surface (132) of the head (13) abuts against the lower running wall (12) (see Figure 4A and 5A The access port (620) of the auxiliary supply conduit (62) is located at the second window (11B) in the side surface (10A) of the swing chamber (1), and thus the auxiliary supply conduit (62) communicates with the lower switching chamber (31) via the access port (620) and the second window (11B). The second discharge port (52) is closed by the side surface (130) of the head (13). The upper switching chamber (30) communicates with the upper part (30A) of the swing chamber (1) via the first window (11A) in the side surface (10A) of the swing chamber (1), and the upper part (30A) of the swing chamber (1) communicates with the first discharge port (51), and thus communicates with the outside, so that the main supply conduit (61) communicates with the lower switching chamber (31) via the auxiliary supply conduit (62), and thus the pneumatic supply source (P1) communicates with the lower part (30B) of the swing chamber (1) (see Figure 4A and Figure 5A (Solid arrow in the image), while the upper part (30A) of the swing chamber (1) is connected to the first discharge port (51), and thus connected to the outside (see solid arrow in the image). Figure 4A and Figure 5A (The dashed arrow in the image) allows the swing piston (10) to be pneumatically pushed upward;

[0080] When the head (13) of the oscillating piston (1) is in the upper running position (PS), and the upper abutting surface (131) of the head (13) abuts against the upper running wall (11) (see Figure 4C and 5CThe access port (620) of the auxiliary supply conduit (62) is located at the first window (11A) in the side surface (10A) of the swing chamber (1), and thus the auxiliary supply conduit (62) communicates with the upper switching chamber (30) via the access port (620) and the first window (11A). The first discharge port (52) is closed by the side surface (130) of the head (13). The lower switching chamber (31) communicates with the lower part (30B) of the swing chamber (1) via the second window (11B) in the side surface (130) of the head (13), and the lower part (30B) of the swing chamber (1) communicates with the second discharge port (51), and thus communicates with the outside, such that the main supply conduit (61) communicates with the upper switching chamber (30) via the auxiliary supply conduit (62), and thus the pneumatic supply source (P1) communicates with the upper part (30A) of the swing chamber (1) (see Figure 4C and Figure 5C (Solid arrow in the image), while the lower part (30B) of the swing chamber (1) is connected to the second discharge port (52), and thus connected to the outside (see solid arrow in the image). Figure 4C and Figure 5C (The solid arrow in the image) allows the swing piston (10) to be pneumatically pushed downwards.

[0081] Therefore, in the improved pneumatic cutting device (100) of the present invention, the switching of the swing of the swing piston (10) in the swing chamber (1) occurs automatically and, due to the presence of the upper switching chamber (30) and the lower switching chamber (31), the switching is realized in the main body (C) directly connected to the swing chamber (1), and is connected to the upper part (30A) of the swing chamber (1) via the first window (11A) and to the lower part (30B) of the swing chamber (1) via the second window (11B).

[0082] In addition, the upper part (30B) and the lower part (30B) of the swing chamber (1) are also connected to the first discharge port (51) and the second discharge port (52), respectively.

[0083] Therefore, the pneumatic activation system is directly implemented in the side of the swing chamber in the main body of the cutting device. The pneumatic activation system is set and guided to switch the swing stroke of the swing piston, thereby making the construction and structure of the pneumatic piston more rational and less complicated. For example, in the opposite rod, in the part located below the swing chamber, there are no longer two annular protrusions and annular recesses.

[0084] Furthermore, the auxiliary supply conduit that allows the upper and lower switching chambers to be alternately placed in connection with the pneumatic supply source is directly implemented in the head of the swing piston, thus making the implementation of the auxiliary conduit in the main body of the device redundant. The auxiliary conduit is necessary for placing the upper annular chamber of the switching chamber in connection with the swing chamber.

[0085] Therefore, the structure of the swing piston (with a rod at the head) is simpler and more slender, and it can achieve a smaller size (length of the lower rod) compared to the cutting device in the previously cited literature.

[0086] Therefore, the improved pneumatic cutting device proposed in this invention is lighter and thus can achieve a significantly higher activation speed, i.e., the speed at which the swing stroke of the swing piston is switched, and thus the speed at which the cutting blade is switched, compared to the prior art.

[0087] Furthermore, the shorter flow path for compressed air supply and discharge enables greater hydrodynamic efficiency, reduces filling and evacuation time, and provides improvements in both speed and compressed air consumption.

[0088] Other particularly advantageous aspects of the improved pneumatic cutting device (100) of the present invention are as follows.

[0089] The improved pneumatic cutting device (100) is formed in such a way that the head (13) of the swing piston (10) is further adapted and sized such that when the head (13) is positioned in the swing chamber (1) at an intermediate position (PM) between the lower running position (PL) and the upper running position (PS), the lower adjacent surface (132) is a first distance from the lower running wall (12) and the upper adjacent wall (131) is a second distance from the upper running wall (11) equal to the first distance (see details). Figure 4B and 5B The first discharge port (51) and the second discharge port (52) are closed by the side surface (130) of the head (13), and the access port (620) of the auxiliary supply conduit (62) is closed by a portion (Z) of the side surface (10A) of the swing chamber (1) located between the upper switching chamber (30) and the lower switching chamber (31), so that the upper part (30A) and the lower part (30B) of the swing chamber (1) are isolated from the pneumatic supply source (P1) and from the outside.

[0090] This allows for control over piston deceleration before the head reaches the end running position (lower or upper) for reversing the swing stroke.

[0091] In practice, as will be described in detail below, an air cushion is produced that performs a braking effect and thus slows down the piston stroke.

[0092] Furthermore, before the piston head reaches contact with the upper or lower running wall, a flow of compressed air will act on it in the opposite direction to its displacement (responsible for the direction of its swing reversal), which will further help to slow down the stroke and thus significantly reduce the amount of material in contact with the upper and lower running walls.

[0093] For example, taking the lower end running position (PL) of the head (13) of the swing piston (10) inside the swing chamber (1) as a reference, wherein the lower adjacent surface (132) of the head (13) is in contact with the lower running wall (12) (see Figure 4A and 5A (as shown in the example).

[0094] In this case, as explained above:

[0095] The access hole (620) of the auxiliary supply conduit (62) is located at the second window (11B) in the side surface (10A) of the swing chamber (1), and thus the auxiliary supply conduit (62) communicates with the lower switching chamber (31) via the access hole (620) and the second window (11B);

[0096] The second discharge port (52) is closed by the side surface (130) of the head (13);

[0097] The upper switching chamber (30) communicates with the upper part (30A) of the swing chamber (1) via a first window (11A) in the side surface (10A) of the swing chamber (1), and the upper part (30A) of the swing chamber (1) communicates with the first discharge hole (51) and thus communicates with the outside.

[0098] This allows the main supply conduit (61) to connect to the lower switching chamber (31) via the auxiliary supply conduit (62), and thus the pneumatic supply source (P1) to connect to the lower part (30B) of the swing chamber (1), while the upper part (30A) of the swing chamber (1) to connect to the first discharge port (51), and thus to the outside.

[0099] Therefore, compressed air from the pneumatic supply source (P1) (see...) Figure 4A and 5A The solid arrow in the middle leads to the lower switching chamber (31) via the main supply conduit (61), the auxiliary supply conduit (62) and the associated access hole (620), and from there enters the lower part (30B) of the swing chamber (1) via the second window (11B).

[0100] Since the upper part (30A) of the swing chamber (1) is connected to the first discharge port (51), and then connected to the outside via the first branch conduit (411) and the discharge conduit (41), the compressed air entering the lower part (30B) of the swing chamber by the head (13) is pushed upward, i.e., towards the upper running wall (11), and the air present in the upper part (30A) of the swing chamber (1) is discharged to the external environment (see Figure 4A and 5A (The dashed arrow in the middle).

[0101] As it rises, the head (13) of the swing piston (10) reaches the intermediate position (PM), see Figure 4B and 5B At the intermediate position, within a very short time, the first discharge port (51) and the second discharge port (52) are closed by the side surface (130) of the head (13), and the access port (620) of the auxiliary supply conduit (62) is closed by a portion (Z) of the side surface (10A) of the swing chamber (1) located between the upper switching chamber (30) and the lower switching chamber (31), so that the upper part (30A) and the lower part (30B) of the swing chamber (1) are isolated from the pneumatic supply source (P1) and from the outside.

[0102] In this configuration, the head (13) of the swing piston (10) is no longer subjected to an upward thrust (when the access hole (620) is closed by a portion (Z) of the side surface (10A) of the swing chamber (1), and its upward displacement due to inertia is opposite to that of the air cushion generated in the upper part (30A) of the swing chamber (1), since the air cushion is no longer in communication with the outside.

[0103] Therefore, in essence, the upward movement of the piston head experiences the first deceleration.

[0104] As it moves upwards due to inertia (i.e., toward the upper running wall 11), the head 13 of the swing piston 10 will pass through the middle position PM (as shown in the image). Figure 4B and 5B (in the middle), and the access hole 620 of the auxiliary conduit 62 will begin to face the first window 11A present in the side surface 10A of the swing chamber 1, and thus enter into communication with the upper switching chamber 30.

[0105] Meanwhile, the first discharge port (51) will continue to be closed by the side surface (130) of the head (13), while the second discharge port (52), which is no longer closed by the side surface (130) of the head (13), will communicate with the lower part (30B) of the swing chamber (1), so the lower part (30B) of the swing chamber (1) will communicate with the external environment.

[0106] Before the upper adjacent surface (131) of the head (13) effectively reaches contact with the upper running wall (11), and therefore before the head (13) reaches the upper running position (PS) (see Figure 4C and 5C The upper part (30A) of the swing chamber is connected to the pneumatic supply source (P1), and thus compressed air begins to enter the upper part (30A) of the swing chamber (1), thereby performing further braking and deceleration. At this moment, there will be a moment when the contact between the upper adjacent surface (131) of the head (13) of the swing piston (1) and the upper running wall (11) is significantly reduced.

[0107] This will result in less stress, less vibration, and less noise.

[0108] Once the swing stroke of the swing piston head reverses, and therefore when the swing piston head moves from the upper running position (PS) ( Figure 4C and 5C ) after passing through the lower running position (PL) (see Figure 4A and 5A ), newly passed through the middle position (PM) ( Figure 4B and 5B The same thing will happen when ),

[0109] In a preferred embodiment, the pneumatic activation system (P) is configured in such a way as to include a connection path (PC) for connecting and maintaining communication between the main supply conduit (61) and the auxiliary supply conduit (62).

[0110] according to Figures 4A to 4C The first embodiment shown implements the connection path (PC) in the following manner.

[0111] The connection path (PC) includes a connection conduit (65) implemented within an auxiliary rod (66), which is carried upward by the head (13) of the swing piston (10) and slidably inserted into a sliding channel (67) implemented in the body (C) above the swing chamber (1) to communicate with the swing chamber (1) via an opening (A) in the upper running wall (11), the second lower end (61B) of the main supply conduit (61A), and the connection conduit (65) extending into the head (13) to connect with the auxiliary supply conduit (62).

[0112] A centering and sealing tool (68) (e.g., an elastic ring) is provided, which is arranged coaxially with the sliding channel (67) and acts externally on the connecting conduit (65) to ensure a sealed sliding connection between the centering and connecting conduit (65) and the sliding channel (67), such that during the oscillation of the oscillating piston (10) in the oscillating chamber (1), and thus during the sliding of the connecting conduit (65) in the sliding channel (67), compressed air from the pneumatic supply source (P1) via the main supply conduit (61) flows exclusively inside the connecting conduit (65) and thus to the auxiliary supply conduit (62).

[0113] Figures 5A to 5C A possible second embodiment of the connection path (PC) is shown.

[0114] In this case, it includes:

[0115] A first connecting conduit (75) is implemented inside the main body (C) in such a way that it includes a first end (75A) communicating with a second end (61B) of the main supply conduit (61) and a second end (75B) communicating with a decanting chamber (76), which is implemented at a position lower than the swing chamber (10) along a sliding seat (14A) of the rod (14), and a second connecting conduit (77) implemented in the rod (14) and having an extension, having a first end located inside the head (13) and connected to the auxiliary supply conduit (62) and a second end at a passage hole (78) present in the rod (14), so as to position the second connecting conduit (77) in communication with the outside of the rod (14).

[0116] In this case, the decanting chamber (76) and the second connecting conduit (77) have extensions and are arranged to each other in such a way that the passage hole (78) is always in communication with the decanting chamber (76) during the oscillation of the head (13) of the oscillating piston (10) between the lower running position (PL) and the upper running position (PS).

Claims

1. An improved pneumatic cutting device (100) with a oscillating blade for a leather cutting machine, comprising: Main body (C); Cutting blade (L), which is used to cut leather pieces (V) stretched on the working plane; The swing chamber (1), which is inside the main body (C), is adapted in such a way to define the upper running wall (11), the lower running wall (12) and the side surface between the upper running wall (11) and the lower running wall (12); A swing piston (10) having a head (13) and a rod (14) is arranged such that its head (13) is inserted into the swing chamber (1) between the upper running wall (11) and the lower running wall (12), and the rod (14) is slidably arranged in a sliding seat (14A), longitudinally realized in the body (C) and connected to the cutting blade (L), wherein the head (13) is adapted in such a way to include an upper abutment surface (131), a lower abutment surface (132) and a side surface; A pneumatic activation system (P) includes a pneumatic supply source (P1) configured such that a first portion (1A) of the swing chamber (1) is included between the head (13) of the swing piston (10) and the lower operating wall (12), and a second portion (1B) of the swing chamber (1) is included between the head (13) of the swing piston (10) and the upper operating wall (11), alternately communicating with the pneumatic supply source (P1) to pneumatically activate the head (13) of the swing piston (10) to the swing. The chamber (1) swings between a lower operating position (PL) and an upper operating position (PS), in which the lower abutting surface (132) of the head (13) abuts against the lower operating wall (12), and in the upper operating position the upper abutting surface (131) of the head (13) abuts against the upper operating wall (11), thus causing the rod (14) and therefore the cutting blade (L) to swing vertically between the lower cutting position (L1) and the upper cutting position (L2) of the leather piece; The swing chamber (1) is adapted in such a way that the upper running wall (11) is arranged at a certain distance relative to the lower running wall (12) such that when the upper abutting surface (131) of the head (13) of the swing piston (10) comes into contact with the upper running wall (11), the cutting blade (L) reaches the upper cutting position (L2) such that it remains substantially in contact with the leather piece to be cut, or is slightly withdrawn, in order to ensure the continuity of the cutting operation; The pneumatic activation system (P) is characterized in that it is configured in such a manner as to include: The first upper switching chamber (30) is arranged in the main body (C) in a first position on the side of the swing chamber (1) and is directly connected to the upper part (30A) of the swing chamber (1) via a first window (11A) formed in the upper part of the side surface of the swing chamber (1). The second lower switching chamber (31) is arranged in the main body (C) in a second position on the side of the swing chamber (1), below the first upper switching chamber (30), and is directly connected to the lower part (30B) of the swing chamber (1) via a second window (11B) formed in the lower part of the side surface of the swing chamber (1). A discharge conduit (41), which is implemented in the body (C) and arranged in such a way as to have a first end communicating with the outside and includes a first branch conduit (411) and a second branch conduit (412), the first branch conduit (411) communicating with the upper part (30A) of the swing chamber (1) via a first discharge hole (51) formed in the side surface of the swing chamber (1), and the second branch conduit (412) communicating with the lower part (30B) of the swing chamber (1) via a second discharge hole (52) formed in the side surface of the swing chamber (1) below the first discharge hole (51); The main supply conduit (61) is implemented in the body (C); A secondary supply conduit (62), which is implemented in the head (13) of the swing piston (10) and opened via an access hole (620) at a point on the side surface of the head (13) of the swing piston (10). The pneumatic activation system (P), the main supply conduit (61), and the auxiliary supply conduit (62) are arranged and configured such that the first end of the main supply conduit (61) is connected to the pneumatic supply source (P1), and the second end (61B) of the main supply conduit (61) is connected to the auxiliary supply conduit (62). And the head (13) of the oscillating piston (10) is sized, and the auxiliary supply conduit (62) is implemented inside the head (13) such that: When the head (13) of the swing piston (10) is in the lower operating position (PL), and the lower abutting surface (132) of the head (13) abuts against the lower operating wall (12), the access port (620) of the auxiliary supply conduit (62) is located at the second window (11B) present in the side surface of the swing chamber (1), and thus the auxiliary supply conduit (62) communicates with the second lower switching chamber (31) via the access port (620) and the second window (11B), the second discharge port (52) is closed by the side surface of the head (13), and the first upper switching chamber (30) communicates with the second lower switching chamber (31) via the access port (620) and the second window (11B) present in the swing chamber. The first window (11A) in the side surface of (1) communicates with the upper part (30A) of the swing chamber (1), and the upper part (30A) of the swing chamber (1) communicates with the first discharge hole (51) and thus with the outside, so that the main supply conduit (61) communicates with the second lower switching chamber (31) via the auxiliary supply conduit (62), and thus the pneumatic supply source (P1) communicates with the lower part (30B) of the swing chamber (1), while the upper part (30A) of the swing chamber (1) communicates with the first discharge hole (51) and thus with the outside, so that the swing piston (10) can be pneumatically pushed upward; When the head (13) of the swing piston (10) is in the upper operating position (PS), and the upper abutting surface (131) of the head (13) abuts against the upper operating wall (11), the access port (620) of the auxiliary supply conduit (62) is located at the first window (11A) present in the side surface of the swing chamber (1), and thus the auxiliary supply conduit (62) communicates with the first upper switching chamber (30) via the access port (620) and the first window (11A), the first discharge port (51) is closed by the side surface of the head (13), and the second lower switching chamber (31) is connected via the head (13). The second window (11B) in the side surface communicates with the lower part (30B) of the swing chamber (1), and the lower part (30B) of the swing chamber (1) communicates with the second discharge port (52) and thus with the outside, so that the main supply conduit (61) communicates with the first upper switching chamber (30) via the auxiliary supply conduit (62), and thus the pneumatic supply source (P1) communicates with the upper part (30A) of the swing chamber (1), while the lower part (30B) of the swing chamber (1) communicates with the second discharge port (52) and thus with the outside, so that the swing piston (10) can be pneumatically pushed downward.

2. The improved pneumatic cutting device (100) according to claim 1, wherein, The head (13) of the swing piston (10) is further adapted and sized such that when the head (13) is positioned in the swing chamber (1) at an intermediate position (PM) between the lower operating position (PL) and the upper operating position (PS), the lower adjacent surface (132) is a first distance from the lower operating wall (12) and the upper adjacent surface (131) is a second distance from the upper operating wall (11) equal to the first distance, the first discharge hole ( 51) and the second discharge port (52) are closed by the side surface of the head (13), and the access port (620) of the auxiliary supply conduit (62) is closed by a portion (Z) of the side surface of the swing chamber (1) located between the first upper switching chamber (30) and the second lower switching chamber (31), in such a way that the upper part (30A) and the lower part (30B) of the swing chamber (1) are isolated relative to the pneumatic supply source (P1) and relative to the outside.

3. The improved pneumatic cutting device (100) according to any one of the preceding claims, wherein, The pneumatic activation system (P) is configured in such a way as to include a connection path (PC) for connecting and maintaining communication between the main supply conduit (61) and the auxiliary supply conduit (62).

4. The improved pneumatic cutting device (100) according to claim 3, wherein, The connection path (PC) includes a connecting conduit (65) implemented within an auxiliary rod (66), which is carried upward by the head (13) of the swing piston (10) and slidably inserted into a sliding channel (67) implemented in the body (C) above the swing chamber (1) to communicate with the swing chamber (1) via an opening (A) in the upper running wall (11), the second end (61B) of the main supply conduit (61), and the connecting conduit (65) extending into the head (13) to connect with the auxiliary supply conduit (62).

5. The improved pneumatic cutting device (100) according to claim 4, comprising a centering and sealing tool (68) arranged coaxially with the sliding channel (67) and acting externally on the connecting conduit (65) to ensure a sealed sliding connection between the centering and the connecting conduit (65) and the sliding channel (67), such that during the oscillation of the oscillating piston (10) in the oscillating chamber (1), and therefore during the sliding of the connecting conduit (65) in the sliding channel (67), compressed air from the pneumatic supply source (P1) via the main supply conduit (61) flows exclusively inside the connecting conduit (65) and thus to the secondary supply conduit (62).

6. The improved pneumatic cutting device (100) according to claim 3, wherein, The connection path (PC) includes: a first connecting conduit (75) realized within the body (C), which includes a first end communicating with the second end (61B) of the main supply conduit (61) and a second end (75B) communicating with a decanting chamber (76), the decanting chamber (76) being realized along the slide seat (14A) of the rod (14) at a position lower than the swing chamber (1); and a second connecting conduit (77) realized within the rod (14) and having an extension so as to have a position located within the head (13) and connected to The second connecting conduit (77) is connected to the first end of the auxiliary supply conduit (62) and the second end of the passage hole (78) in the rod (14) to place the second connecting conduit (77) in communication with the outside of the rod (14), wherein the decanting chamber (76) and the second connecting conduit (77) have extensions and are arranged to each other in such a way that the passage hole (78) is always in communication with the decanting chamber (76) during the oscillation of the head (13) of the oscillating piston (10) between the lower operating position (PL) and the upper operating position (PS).

Images