Automatic clinching machine

Abstract

 According to the invention, a clamping machine is carried out, that includes: a frame (2) provided with a handgrip (3) and with a housing (4) suitable for a case (5) containing a certain quantity of clamps (6); a pair of pliers (9) for the fastening of the clamps, constituted by a pair of jaws (13) hinged to the frame, the rear ends of which (12) are connected with each other and with the mobile element (89) of an actuator (90) that opens and closes the pliers (9) by means of a junction element; an extractor (8) sliding on the frame (2), for the extraction of the clamps (6, 25) from the case (5) one after the other and suitable for placing them in clamping position between the jaws (13) of the pliers (9). Said junction element is a fork (88) sliding on the frame (2) and fixed on one side directly to the mobile element (89) of the actuator (90) and on the opposite side to the rear ends (12) of the jaws (13) of the pliers (9) by means of the same hinge pin (87) that can be connected with the extractor (8). Further, said fork (88) and said frame (2) support the means(14, 30, 33, 17, 18) engaging and disengaging said pin (87) with the extractor (8).

Description

[0001] The invention is an automatic clamping machine.

[0002] Clamping machines are known, by means of which particular packaging jobs are carried out, for example in the field of packing, upholstery, metal structural works and in the manufacture of stress bars for reinforced concrete and alike.

[0003] In particular, the manufacture of stress bars for reinforced concrete is carried out with a known type of clamping machine, basically constituted by a frame equipped with a handgrip and a case containing a certain quantity of metal clamps. These clamps are extracted one after the other and fastened by means of pliers projecting from the front part of the frame itself.

[0004] The pliers consist of two jaws, opposed to each other, between which the metal clamp to be fastened is placed: the external perimeter of the clamp coincides with the internal perimeter of the pliers.

[0005] When the operator who is using the clamping machine presses a push button or moves a lever, he operates those mechanical parts of the clamping machine that close the jaws of the pliers, in such a way as to fasten the clamp around the element or elements that must be secured together.

[0006] When the push button or the lever are released, the pliers open again and during this phase they extract a new clamp from the case and put it between the jaws, ready to clamp it as soon as they are closed by means of the push button or of the control lever.

[0007] In the known clamping machines, while the pliers, which are arc-shaped, are closing, the clamp always adheres to the jaws, so that when the pliers are completely closed and the clamp is completely fastened, the latter takes the shape of an eyelet, which is substantially the configuration of the closed pliers.

[0008] This means that the pliers cannot let the clamp adhere to the element or elements around which it is fastened, unless the element or elements in their junction point have a perimeter equal to the internal perimeter of the eyelet formed by the clamp when it is closed.

[0009] In conclusion, the pliers can fasten the clamp around bodies the section of which has a shape similar to that of the closed pliers and having a perimeter equal to the internal perimeter of the clamp when the pliers are closed. This represents a considerable inconvenience, since the user, when he has to clamp elements having different measures, is forced to employ and therefore to buy more than one clamping machine, each one provided with pliers with different dimensions and making use of clamps having different dimensions, too.

[0010] The clamping machines that are known at the moment have another disadvantage: they are characterized by the necessity to feed the new clamp manually after the previous one has been closed, so that the operator must use both hands. Further, this kind of clamping machines cannot work in continuous cycle.

[0011] The present invention is aimed at eliminating the above mentioned inconveniences.

[0012] The main objective of the invention is to carry out a clamping machine that, by means of single closing pliers, should allow the user to fasten clamps around one or more elements having different dimensions.

[0013] Another objective is that this clamping machine should fasten one or more elements having different dimensions with clamps of the same size.

[0014] Further, this clamping machine should also be capable of operating in continuous automatic cycle.

[0015] Finally, it should also be possible for the user to operate this clamping machine with one hand only.

[0016] The above aims are reached by means of a clamping machine that, in conformity with the main claim, consists of:

• a frame provided with a handgrip and a housing for a case containing a certain quantity of clamps;
• pliers for fastening the clamps, consisting of a pair of jaws hinged to the frame, the rear ends of which are connected with each other and with the mobile member of an actuator that operates the opening and closing of the pliers by means of a junction element;
• an extractor that slides on the frame and extracts the clamps from the case one after the other, capable of placing them in the proper clamping position between the pliers jaws,

characterized in that the above mentioned junction element is a fork that slides on the frame and is fixed on one side directly to the mobile member of the actuator and on the opposite side to the rear ends of the pliers jaws, by means of the same hinge pin that can be connected with the extractor, said fork and said frame supporting also the means engaging and disengaging said pin with the extractor.

[0017] According to an execution that is preferred to others, the extractor consists of a fork having a fixed, C-shaped profile that slides horizontally on the upper part of the frame.

[0018] The closing pliers are composed of a pair of jaws hinged to the frame and opposed to each other at the extractor sides. The rear ends of the pliers jaws are connected, by means of a mobile pin, with a fork that is fixed to the end of the stem of a pneumatic cylinder that with its movement causes the opening and closing of the jaws.

[0019] The mobile pin is provided with a toothed element that rotates when it bucks against reaction elements.

[0020] Said toothed element is also provided with thrusting parts, through which it is lifted or lowered when it rotates due to the bucking against the reaction elements.

[0021] In particular, when the toothed element is lifted, it disengages the pin from the coupling with the extractor and, on the contrary, when it is lowered it couples the pin with the extractor. In the first case it causes the stop of the extractor in the reached position and in the second case it causes the movement of the extractor when the pliers are opened or closed.

[0022] Among the advantages offered by this new clamping machine there are a greater flexibility in the use and a saving in the purchase of the equipment, since with one clamping machine only it is possible to clamp elements having different dimensions.

[0023] Further, this machine, being designed for operation in continuous automatic cycle, makes for a greater working speed and therefore for reduced production costs.

[0024] The purpose and the described advantages are better exemplified in the description of one among many of the practical applications of the invention in question, illustrated in the attached tables:

• Fig. 1 shows an axonometric view of the clamping machine that is the object of the present invention;
• Fig. 2 shows the clamping machine of Fig. 1, without the covering case;
• Fig. 3 shows the clamping machine of Fig. 2 without the closing pliers, with exploded view of its components;
• Fig. 4 shows the clamping machine seen from above, with the extractor during the extraction of a clamp;
• Fig. 5 shows the clamping machine of Fig. 4, with the clamp extracted and being put between the jaws of the pliers;
• Fig. 6 shows the toothed element and the coupling pin that are connected with the fork, in the position they have when the clamping machine is positioned as shown in Fig. 5;
• Fig. 7 shows the toothed element and the coupling pin of Fig. 6, in the position they have when the clamping machine is positioned as shown in Fig. 4;
• Fig. 8 shows the clamping machine of Fig. 5 while it is fastening the clamp;
• Fig. 9 shows the clamping machine of Fig. 8 with the clamp at the end of the closing phase;
• Fig. 10 shows the three axonometric views of the toothed element and of the coupling pin that are connected with the fork, with the toothed element in lowered position;
• Fig. 11 shows the three axonometric views of the elements of Fig. 10, with the toothed element lifted by the thrusting parts;
• Fig. 12 shows a partial front axonometric view of the clamping machine from the pliers' side.

[0025] The clamping machine object of the present invention is represented in Fig. 1 and 2, where it is indicated in its whole with 1 and is composed of a clamping unit, indicated in its whole with 7, which is composed of the extractor 8 and of the pliers 9. This clamping unit projects from the front part of a frame 2 that is equipped in its lower part with a handgrip 3 and a housing 4, suitable for a case 5 containing a certain quantity of stacked clamps 6.

[0026] Said extractor 8 and pliers 9 can be seen in detail in Fig. 2, where the clamping machine 1 is shown without the case 10, visible in Fig. 1, which protects the leverage 11 that operates the pliers 9.

[0027] As regards the extractor 8 in particular, see Fig. 3, where the clamping machine is shown without the pliers 9, in order to offer a clearer description.

[0028] It is possible to observe that the extractor consists of a C-shaped fork 81, obtained in the front part of a plane slide 82, coupled on the upper part of frame 2.

[0029] Said plane slide 82 adheres to frame 2 by means of a covering plate 83, which is provided with side slide guides 85 and with holes 84 for passing the fastening screws through to frame 2.

[0030] The plane slide 82 has in its rear part a hole 86, in which a hinge pin 87 is inserted. This hinge pin 87 is part of a fork 88 fixed to the stem 89 of a pneumatic cylinder 90 that operates the pliers.

[0031] As regards the fork 88, shown in clearer detail in Fig. 6 and 7, it is fixed to the stem 89 of the pneumatic cylinder operating the pliers. It is possible to observe that the hinge pin 87 passes through the fork and also through the rear ends 12 of the jaws 13 that constitute the pliers 9 and belong to the leverage operating the pliers, indicated in its whole with 11 and visible in detail in Fig. 4 and 5, 8 and 9.

[0032] Said hinge pin 87 is fixed in its upper part, as can be seen in detail in Fig. 10 and 11, to a toothed element that adheres to the fork 88 by means of a spring 30.

[0033] Said toothed element 14 can rotate only in the preferably clockwise direction indicated by the arrow 15, since its teeth 16 cannot rotate in the opposite direction owing to the presence of the stop element 17 fixed to the fork 88. Fig. 10 and Fig. 11, as well as Fig. 7 and Fig. 6, show that the adherence of the toothed element 14 to the fork 88 takes place through the interposition of thrusting parts consisting of a pair of balls 18, each one of which is positioned in a housing 19 obtained in the fork 88 and thrusts against the toothed element 14, either acting against its surface 40, as shown in Fig. 11, or interfering in the holes 29 or 30 obtained in the surface 40 itself, as shown in Fig. 10.

[0034] Finally, it is possible to observe that in its lower part the fork 88 has a bucking tooth 21, which, as shown in Fig. 3, acts against the terminal part 42 of the plane slide 82, which feeds the clamp 25 for the extraction when the pneumatic cylinder 90 is operated.

[0035] The operation of the clamping machine starts from Fig. 4, where the fork 81 of the extractor 8 holds a clamp 25, while the jaws 13 of pliers 9 are closed.

[0036] By means of the control lever 27, visible in Fig. 2, the valve 28 is operated, which feeds the positive chamber of the pneumatic cylinder 90 and makes the stem 89 of the pneumatic cylinder itself advance in the direction 26, as indicated in Fig. 4.

[0037] In this position, as shown in Fig. 7, the thrusting balls 18 are housed in the holes 29 of the toothed element 14, which is pushed downwards by the action of the spring 30, so that the end 31 of the hinge pin 87 is constrained in the hole 86 of the plane slide 82 that constitutes the extractor 8.

[0038] In this situation during the advancement of the stem 89 in the direction 26 the opening of the jaws 13 of pliers 9 and the advancement of the extractor 8 that extracts a clamp 25 from the case 5 take place contemporaneously.

[0039] When the pneumatic cylinder 90 reaches its positive end of stroke, the clamping machine is positioned as shown in Fig. 5, that is, with the clamp 25 fixed to the fork 81 of the extractor 8 and held between the jaws 13 of the pliers 9, that are open and therefore ready to fasten the clamp 25 itself.

[0040] It should be observed that during this stroke in the direction 26 the tooth 32 of the toothed element 14 that can be seen in Fig. 4 contacts the reaction element 33 fixed to the frame 2 of the pliers and causes a rotation of the toothed element 14 in the direction indicated by the arrow 34.

[0041] This way, when the pneumatic cylinder 90 reaches the end of stroke and the clamping machine is positioned as indicated in Fig. 5, the toothed element 14 has had a rotation that has raised it with respect to fork 88 as shown in Fig. 6. Said toothed element is thrusted upwards by the opposition of the thrusting balls 18 that, no more in the holes 29, buck against the lower part of its surface 40 as shown in Fig. 5 and 6.

[0042] So, as it is possible to observe in Fig. 6, the hinge pin 87 takes its end 31 out of the hole 86 made in the extractor 8, which remains in the reached position and holds the clamp 25 in the clamping position between the pliers jaws. The fastening of the clamp takes place when, as it can be observed in Fig. 8, the stem 89 of the pneumatic cylinder 90 goes back in the direction 35, that is opposite to the previous advancement direction 26.

[0043] During this closing action the extractor 8 remains in the reached position, locked by the elastic pin shown in Fig. 3, where it is indicated with number 36. Said elastic pin is fixed to the frame 2 and goes into a housing 70 corresponding to it, made on the bottom of the fork 81 of the extractor 8.

[0044] In fact, during this closing phase it is essential for the extractor 8 to hold the clamp 25 fixed in its position between the jaws of the pliers.

[0045] The fastening of the clamp 25 ends when the stem 89 of the pneumatic cylinder 90 reaches the negative end of stroke, position in which, as shown in Fig. 9, the clamp 25 is completely fastened around an element 36 by the action of the jaws 13 of the pliers 9, that close completely.

[0046] It is important to observe in Fig. 8 that the tooth 37 of the toothed element 14, moving from the position shown in Fig. 5 to that shown in Fig. 9, passes before the operating element 33. Said operating element 33, even if it contacts the tooth 37, cannot let the toothed element 14 rotate in the direction indicated by the arrow 38 due to the reaction of the stop element 17 against the tooth 39; consequently, the hinge pin 37 remains disengaged from the extractor 8 until the clamp 25 is completely fastened.

[0047] At this point it is necessary to proceed and have the extractor 8 return to the initial position shown in Fig. 4, in order to be able to extract another clamp.

[0048] For this purpose, the valve 28 that feeds the positive chamber of the pneumatic cylinder 90 is operated again by means of the lever 27, so that the stem 89 of the cylinder advances in the direction 26 causing the opening of the jaws 13 of the pliers 9, as shown in Fig. 5.

[0049] Before carrying out this operation the element 86 with the clamp 25 fastened around it have obviously been removed.

[0050] It can be observed that passing from the position shown in Fig. 9 to the final position shown in Fig. 5 the tooth 37 passes before the reaction element 33, which causes the new rotation of the toothed element 14 in the direction 34, thus lifting the thrusting balls 18 that go into another pair of holes 39 made in the toothed element 14, represented in Fig. 4, 5, 8 and 9.

[0051] The hinge pin 37 is thus moved downwards by the thrust of the spring 30 and it reaches a position equal to that represented in Fig. 7, where its end 31 goes into the hole 86 made on the plate 82 that constitutes the extractor 8. Operating the lever 27 and then the valve 28 again, the negative chamber of the pneumatic cylinder 90 is put under pressure again, so that the stem 89 goes back in the direction 35 carrying the jaws 13 of the pliers 9 and the extractor 8 in a back position, as shown in Fig. 4.

[0052] During this backing action, the force exerted by the cylinder 90 overcomes the force of the elastic pin 36 that keeps the extractor 8 constrained, so that said elastic pin 36 goes out of the housing 70 and allows the return of the extractor itself.

[0053] As regards the fork 88, its bucking tooth 21 serves to keep thrusting the extractor 8 in the direction 26 after the reaction element 33, acting against the tooth 32 of the toothed element 14, has lifted it vertically disengaging the end 31 of the hinge pin 87 from the hole 86 that couples it with the extractor 8.

[0054] It is easy to understand, in fact, that without the bucking tooth 21 the extractor 8 itself, if not operated any longer, would stop in the position reached before being locked by the elastic stop pin 36.

[0055] It can be noticed, observing also Fig. 10 and 11, that the fork 88 has the base 50, for the sliding on the frame 2 of the clamping machine, inclined with respect to the vertical axis 41. This happens because, as shown in Fig. 12, the jaws 13 that constitute the pliers 9 must move on two planes inclined with respect to each other, in order to be superimposed as shown in Fig. 9 and to fasten the clamp 25 completely.

[0056] According to the above description, the clamping machine object of the present invention reaches the fixed aims.

[0057] We have seen, in fact, that single closing pliers make for the fastening of the same kind of clamp around two or more elements having different dimensions.

[0058] We have seen also that the advancement of the clamps takes place automatically during the operation of the pneumatic cylinder 90 that causes the opening of the pliers 9. This happens thanks to the hinge pin 87 belonging to the fork 88, which connects the stem 89 of the cylinder to the rear end 12 of the jaws 13. The hinge pin makes the fork 88 integral with the extractor 8.

[0059] Besides being automatic, which means that it does not need the manual feeding of each single clamp, the clamping cycle is continuous owing to the operation of the lever 27 that by means of a distribution valve 28 feeds alternately and continuously the positive and the negative chamber of the pneumatic cylinder 90.

[0060] In the execution phase changes can be made in the clamping machine, as regards the shape of the jaws or the profile of the fork that constitutes the extractor, the shape of the toothed element 14 or of the elements that engage and disengage the hinge pin.

[0061] An advantage is represented by the fact that for the operation of the clamping machine instead of a pneumatic cylinder 90 any other actuator, hydraulic or electric, can be employed.

[0062] It is understood, in any case, that all these possible variations are protected by the present invention.

Claims

1. Clamping machine comprising:

- a frame (2) provided with a handgrip (3) and with a housing (4) suitable for a case (5) containing a certain quantity of clamps (6);

- pliers (9) for fastening the clamps, constituted by a pair of jaws (13) hinged to the frame, the rear ends of which (12) are connected with each other and with the mobile element (89) of an actuator (90) that provides for the opening and closing of the pliers (9) by means of a junction element;

- an extractor (8) sliding on the frame (2) for the extraction of the clamps (6, 25) from the case (5) one after the other and suitable for placing them in clamping position between the jaws (13) of the pliers (9),

characterized in that said junction element is a fork (88) sliding on the frame (2) and fixed on one side directly to the mobile element (89) of the actuator (90) and on the opposite side to the rear ends (12) of the jaws (13) of the pliers (9) by means of the same hinge pin (87) connectable with the extractor (8), said fork (88) and said frame (2) supporting means (14, 30, 33, 17, 18) engaging and disengaging said pin (87) with the extractor (8).

2. Clamping machine according to claim 1), characterized in that the extractor (8) consists of a plane slide (82) presenting, in correspondence with one end, a fork (81) suitable for housing a clamp (6, 25) during the extraction from the case (5) in which it is contained, said fork (81) being provided, in correspondence with its bottom, with a housing (70) for an elastic pin (86), fixed to the frame (2) and locking the extractor (8) when said extractor places said clamp (6, 25) in the fastening position in the pliers (9).

3. Clamping machine according to claim 1), characterized in that the hinge pin (87) passes and slides through the corresponding holes made both in the fork (88) and in the rear ends (12) of the jaws (13) that it couples with said fork (88).

4. Clamping machine according to claim 1), characterized in that the fork (88) has the base (50) for the sliding on the frame (2) inclined with respect to a vertical axis (41).

5. Clamping machine according to claim 1), characterized in that the fork (88) has, in correspondence with its base (50), a bucking tooth (21) that acts against the terminal part (42) of the extractor (8).

6. Clamping machine according to claim 1), characterized in that the means engaging and disengaging the pin (87) with the extractor (8) consist of:

- a toothed element (14) fixed in its upper part to the hinge pin (87) and provided with several teeth (16, 32, 37), at least one of which acts permanently against a stop element (17) fixed to the fork (28);

- a reaction element (33) fixed to the frame (2) against which the teeth (16, 32, 37) of the toothed element (14) act when the fork (88) is advanced by the actuator (90);

- at least one pair of thrusting balls (18), each one housed in a seat (19) obtained in the fork (88) and acting against the surface (40) of the toothed element (14) or housed in one of the holes (29, 39) made in the toothed element (14) itself.

7. Clamping machine according to claim 1), characterized in that when it is connected with the extractor (8) the hinge pin (87) has its end (31) internally coupled with a hole (36) made in the plane slide (82) that constitutes said extractor (8).

Drawing