Preforming machine for the heat bonding or cold shaping of the back-counter between the lining and the upper of shoes

Abstract

 A preforming machine for the heat bonding or cold shaping of the back-counter between the lining and the upper of shoes comprising a supporting structure (2) which supports a forming cushion (4), which provides a forming cavity (5) for the rear part of the upper (6) of a shoe and can move on command, in an actuation direction (3) which has a vertical component, from a raised standby position to a lowered working position. The machine further comprises a last (7) which is adapted to support the upper (6) of a shoe and is hinged to the supporting structure (2) about a horizontal pivoting axis (8). The last (7) is able to rotate on command about its pivoting axis (8) from a standby position, in which it is offset with respect to the forming cavity (5), to a working position, in which it is vertically aligned with the forming cavity. Actuation means (10) for the forming cushion (4) are provided in order to transfer it from its standby position to its working position and viceversa. Means (17,18) are also provided for connecting the actuation means (10) to the last for the transfer of the last (7) from its standby position to its working position or viceversa as a consequence of the activation of the actuation means (10).

Description

[0001] The present invention relates to a preforming machine for the heat bonding or cold shaping of the back-counter between the lining and the upper of shoes.

[0002] Preforming machines are known for performing the heat bonding or cold shaping of the back-counter, which is constituted by a reinforcement layer, between the lining and the upper of shoes at the rear part of the shoe.

[0003] Preforming machines have a last on which the upper is fitted so that its rear part faces upward; the back-counter is inserted beforehand between the lining and the upper. The last is then inserted in the forming cavity of a forming cushion which is arranged above the last and achieves the heat bonding or cold shaping of the back-counter between the lining and the upper.

[0004] In preforming machines that perform the cold shaping of the back-counter, the last is internally provided with ducts for the circulation of a coolant, while in preforming machines that perform the heat bonding of the back-counter the forming cushion is conveniently heated, usually by means of electric resistors.

[0005] In some preforming machines, the last can rotate about a horizontal axis which is parallel to the front side of the machine and can also move along a direction which has a vertical component.

[0006] In practice, by using this double freedom of motion, the last is moved from a standby position, in which it is offset with respect to the forming cavity of the forming cushion toward the front side of the machine, so as to allow the operator to easily fit the upper on the last, to a working position, in which it is aligned with the forming cavity; once it is in the working position, it is raised so as to insert the rear part of the upper fitted on the last into the forming cavity of the forming cushion.

[0007] These machines suffer the problem of possible error in the motion for aligning the last with respect to the forming cavity of the overlying forming cushion. If the rotation of the last is insufficiently precise due to wear of the elements that provide the support and articulation of the last or due to the presence of dirt on said elements, the last is lifted into an imperfect alignment with the forming cavity of the forming cushion. Accordingly, an impact can occur between the last and the forming cushion, with consequent damage to these elements of the machine.

[0008] In practice, the double movement of the last and the elements that actuate this double movement cause the operation of these machines to be less than fully reliable.

[0009] In other kinds of preforming machine, the last is simply able to rotate about a horizontal pivoting axis which is parallel to the front side of the machine, while the forming cushion can move with respect to the last in a vertical direction.

[0010] In practice, the last is simply able to rotate about its own pivoting axis in order to move from a standby position, in which it is arranged on the front side of the machine in order to allow the operator to fit thereon the upper with the back-counter inserted between the upper and the lining, to a working position, in which it is rotated toward the rear side of the machine, with respect to the standby position, so as to move into alignment with the forming cavity of the forming cushion which is arranged in an upward region.

[0011] In these machines, the forming cushion can travel in a substantially vertical direction, so as to move from a standby position, in which it is raised above the last, to a working position, in which it is lowered around the last.

[0012] In these machines, the oscillation of the last about its own pivoting axis is provided by means of a first pneumatic cylinder and the vertical movement of the forming cushion is provided by means of a second pneumatic cylinder.

[0013] The use of two pneumatic cylinders for actuating the last and the forming cushion, respectively, entails the problem of considerably affecting the production costs of these machines, also because each pneumatic cylinder requires its own pneumatic actuation circuit.

[0014] Furthermore, these machines have working cycle times which cannot be reduced below a certain limit because the actuation of the two pneumatic cylinders must occur sequentially.

[0015] Another drawback of these machines consists in that when the machine is switched off the last and the forming cushion can arrange themselves in random and abnormal positions, entailing a danger for the user when work resumes.

[0016] The aim of the present invention is to solve the above problems by providing a preforming machine which is structurally simple and can have high operating reliability.

[0017] Within the scope of this aim, an object of the invention is to provide a preforming machine in which the correct positioning of the last with respect to the forming cushion is ensured in any operating condition.

[0018] A further object of the invention is to provide a preforming machine which can have a faster working cycle than conventional preforming machine.

[0019] A still further object of the invention is to provide a preforming machine which can have reduced production costs with respect to conventional preforming machine.

[0020] A further object of the invention is to provide a preforming machine which effectively avoids any abnormal positioning of the last and of the forming cushion when the machine is switched off.

[0021] This aim, these objects and others which will become apparent hereinafter are achieved by a preforming machine for the heat bonding or cold shaping of the back-counter between the lining and the upper of shoes, comprising a supporting structure which supports: a forming cushion, which provides a forming cavity for the rear part of the upper of a shoe and can move on command, in an actuation direction which has a vertical component, from a raised standby position to a lowered working position, and viceversa, and a last which forms a support for the upper of a shoe and is hinged to said supporting structure about a horizontal pivoting axis, said last being able to rotate on command about said pivoting axis from a standby position, in which it is offset with respect to said forming cavity, to a working position, in which it is vertically aligned with said forming cavity, and viceversa, actuation means for said forming cushion being provided in order to transfer it from its standby position to its working position or viceversa; characterized in that it comprises means for connecting said actuation means to said last for the transfer of said last from its standby position to its working position or viceversa as a consequence of the activation of said actuation means.

[0022] Further characteristics and advantages will become apparent from the following detailed description of a preferred but not exclusive embodiment of the preforming machine according to the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

Figure 1 is a schematic perspective view of the machine according to the invention;

Figure 2 is a partially sectional schematic side elevation view of the machine according to the invention, with the last and the forming cushion in their respective standby positions;

Figure 3 is a view, similar to Figure 2, of the machine with the last and the forming cushion in their respective working positions;

Figure 4 is an enlarged-scale perspective view of a detail of the machine related to the means for connecting the forming cushion to the last.

[0023] With reference to the above figures, the preforming machine according to the invention, generally designated by the reference numeral 1, comprises a supporting structure 2 which supports, so that it can slide in an actuation direction 3 which has a vertical component, a forming cushion 4 inside which there is a forming cavity 5 for the rear part of the upper 6 of a shoe.

[0024] The forming cushion 4 can move on command along the direction 3 from a raised standby position to a lowered working position and viceversa.

[0025] The machine further comprises a last 7 on which the upper 6 is to be fitted; said last is pivoted to the supporting structure 2 about a horizontal pivoting axis 8 which is parallel to the front side of the machine, designated by the reference numeral 9.

[0026] The last 7 can rotate on command about the pivoting axis 8 in order to move from a standby position, in which it is offset, toward the front side 9 of the machine, with respect to the forming cavity 5, to a working position, in which it is rotated toward the rear side of the machine with respect to the standby position, so as to align with the forming cavity 5 of the forming cushion 4, and viceversa.

[0027] The machine further comprises means 10 for actuating the forming cushion 4 in order to transfer it from the standby position to the working position and viceversa.

[0028] According to the invention, means are provided for connecting the actuation means 10 to the last 7 so as to achieve, by way of said actuation means 10, the transfer of the last 7 from the standby position to the working position or viceversa.

[0029] More particularly, the forming cushion 5 is fixed to a slider 11 which can slide along a pair of guides 12a and 12b which run parallel to the direction 3 and are rigidly fixed to the supporting structure 2.

[0030] The guides 12a and 12b are inclined toward the rear side of the machine starting from their lower end toward the upper end.

[0031] The actuation means 10 are preferably constituted by a fluid-driven cylinder 13, for example a pneumatic cylinder, which is fixed by means of its body to the supporting structure 2 and is arranged so that its axis is parallel to the guides 12a and 12b, i.e., to the direction 3. The stem 13a of the piston of the cylinder 13 is connected to the slider 11.

[0032] The last 7 is fitted on a support 14 which is hinged to the supporting structure 2 about the pivoting axis 8. Grippers 15 are mounted on the support 14 in a per se known manner for locking and tensioning the upper 6 once it has been fitted on the last 7; said grippers 15 are actuated by a pneumatic cylinder 16.

[0033] The means for connecting the actuation means 10 to the last 7 are preferably constituted by a cam 17, which is rigidly coupled to the slider 11, and by a cam follower 18, which is connected to the support 14 of the last 7.

[0034] The cam 17 is preferably constituted by a slot formed in a plate 19 which is fixed to the slider 11. The slot has a first portion 17a which runs transversely to the direction 3, toward the rear side of the machine, and a second portion 17b which runs substantially parallel to the extension of the guides 12a and 12b.

[0035] The first portion 17a in practice actuates the rotation of the last 7 about the axis 8, while the second portion 17b completes the lowering of the forming cushion 4 in its transfer from the standby position to the working position when the last 7 is in its working position and viceversa.

[0036] The cam follower 18 is constituted by an idly rotating wheel associated with the support 14 of the last 7.

[0037] According to requirements, the last 7 can be internally provided with ducts for circulating a cooling fluid, if the preforming machine must perform a cold shaping of the back-counter, or the forming cushion 4 can be provided with heating means, for example electric resistors, if the preforming machine is meant to produce a heat bonding of the back-counter with the upper 6 and the lining of shoes.

[0038] The operation of the preforming machine according to the invention is as follows.

[0039] At the beginning of the working cycle, the last 7 is in the standby position, i.e., it is directed toward the front side 9 of the machine while the forming cushion 4 is also in its standby position, i.e., raised above the last 7, as shown in particular in Figure 2.

[0040] The operator fits on the last 7 the upper 6 with the corresponding lining and with the back-counter arranged between the lining and the upper in the rear region thereof.

[0041] The upper 6 is locked by the grippers 15 and the pneumatic cylinder 13 is then actuated. The actuation of the pneumatic cylinder 13, owing to the particular configuration of the cam 17, as the lowering of the forming cushion 4 begins, turns the last 7 about the pivoting axis 8, moving the last 7 from the standby position to the working position, in which the last 7 is rotated toward the rear side of the machine with respect to the standby position and in alignment with the forming cavity 5 of the forming cushion 4.

[0042] At the end of this first step, the cam follower 18 has moved along the first portion 17a of the cam 17 and has reached the beginning of the second portion 17b.

[0043] The stem 13a of the pneumatic cylinder 13 then continues its stroke, while the cam follower 18 slides along the second portion 17b of the cam 17. In this manner, the forming cushion 4 is lowered into the working position, i.e., so that the forming cavity 5 is fitted around the last 7, thus producing the cold shaping or heat bonding of the back-counter between the upper 6 and the lining, as shown in particular in Figure 3.

[0044] The actuation of the pneumatic cylinder 13 in the opposite direction returns the forming cushion 4 and the last 7 to the respective standby positions.

[0045] It should be observed that the connection between the slider 11 and the support 14, provided by means of the cam 17, also achieves a perfect synchronization between the movement of the forming cushion 4 and the last 7, also minimizing the time required for performing a working cycle.

[0046] In practice it has been observed that the preforming machine according to the invention fully achieves the intended aim, since by using a single actuation element both for the forming cushion and for the last, it is structurally more simple, more precise and more reliable than conventional preforming machines.

[0047] Another advantage of the preforming machine according to the invention is that it prevents abnormal relative movements between the forming cushion and the last, thus avoiding mutual collisions and offering the greatest assurances of safety for the operator.

[0048] The preforming machine thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; all the details may also be replaced with other technically equivalent elements.

[0049] In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

[0050] The disclosures in Italian Patent Application No. MI98A000968 from which this application claims priority are incorporated herein by reference.

[0051] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A preforming machine for the heat bonding or cold shaping of the back-counter between the lining and the upper of shoes, comprising a supporting structure (2) which supports: a forming cushion (4), which provides a forming cavity (5) for the rear part of the upper (6) of a shoe and can move on command, in an actuation direction (3) which has a vertical component, from a raised standby position to a lowered working position, and viceversa, and a last (7) which forms a support for the upper (6) of a shoe and is hinged to said supporting structure (2) about a horizontal pivoting axis (8); said last (7) being able to rotate on command about said pivoting axis (8) from a standby position, in which it is offset with respect to said forming cavity (5), to a working position, in which it is vertically aligned with said forming cavity, and viceversa; actuation means (10) for said forming cushion (4) being provided in order to transfer it from its standby position to its working position or viceversa; characterized in that it comprises means (17,18) for connecting said actuation means (10) to said last (7) for the transfer of said last (7) from its standby position to its working position or viceversa as a consequence of the activation of said actuation means (10).

2. The machine according to claim 1, characterized in that said forming cushion (4) is supported by said supporting structure (2) so that it can slide along guides (12a,12b) which run at an angle, starting from the bottom upward, toward the rear side of the machine.

3. The machine according to claim 1, characterized in that said pivoting axis (8) is arranged proximate to the front side of the machine and is parallel to the front side of the machine.

4. The machine according to claim 1, characterized in that said connection means (17,18) comprise a cam (17) which is associated with said forming cushion (4) and is engageable by a cam follower (18) associated with said last (7).

5. The machine according to claim 4, characterized in that said cam (17) comprises a slot formed in a plate (19) which is rigidly coupled to said forming cushion (4), said slot having a first portion (17a) which lies transversely to said actuation direction (3) toward the rear side of the machine and a second portion (17b) which lies substantially parallel to said actuation direction (3), said first portion (17a) actuating the rotary motion of said last (7) about said pivoting axis (8) from its standby position to its working position and said second portion (17b) completing the transfer of said forming cushion (4) from its standby position to its working position when said last (7) is in its working position and viceversa.

6. The machine according to claim 2, characterized in that said forming cushion (4) is mounted on a slider (11) which can slide along said guides (12a,12b), said actuation means (10) comprising an actuator (13) which acts on said slider (11) for its alternating translatory motion along said guides (12a,12b).

7. The machine according to claim 6, characterized in that said actuator (13) comprises a fluid-actuated cylinder (13) which is supported by said supporting structure (2) and is orientated so that its axis is parallel to said guides (12a,12b), said fluid-actuated cylinder being connected to said slider (11) by way of the stem (13a) of its piston.

8. The machine according to claim 1, characterized in that said forming cushion (4) is constituted by a cold-forming cushion.

9. The machine according to claim 1, characterized in that said forming cushion (4) is constituted by a beat bonding cushion.

Drawing