ES1328151U - A sewing machine, adapted to close bags by sewing (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

A sewing machine (100), adapted for closing bags by sewing, creating long bag tails, of the type that uses a needle (1.1) and a corresponding hook (2.1) to interlace the thread (7.1) from a bobbin (7) with the thread threaded onto the needle (1.1), creating the stitch, the machine comprising a first and a second head (1, 2), the first head (1) with the needle (1.1) and mechanical means for moving the needle driven by the reciprocating motion of a foot (12.1) of a connecting rod (12) of a connecting rod-crank mechanism, and the second head (2) with the hook and mechanical means for moving the hook driven by the rotation of a handwheel, the machine being characterized in that it further comprises a rigid frame, which supports a first arm (11), a second arm (12) and a bridge (13) joining the first and second arms, where the ends of the first and second arms (11, 12) support the first and second heads (1, 2), respectively, opposed, providing a separation to accommodate a thickness of bag to be closed by sewing and providing a distance D, between the needle (1.1) and the bridge (13), which is greater than 200 mm capable of accommodating a bag tail of a similar length, and a drive motor (5) which by means of a kinematic chain moves the connecting rod-crank mechanism and the handwheel, where said kinematic chain is based on a pulley system comprising - a first set of pulleys, with a first pulley (41) rotating about an axis (41.1) supported on the first arm (11) and which performs the function of crank of the connecting rod-crank mechanism, first pulley (41) to which the head (12.2) of the connecting rod (12) of the connecting rod-crank mechanism is connected, where said first pulley (41) links with a second pulley (42) which is integral with a first transmission shaft (51) supported rotatably on the bridge (13), and - a second set of pulleys, with a third pulley (43) also integral with the first transmission shaft (51), wherein said third pulley (43) connects inside the bridge (13) with a fourth pulley (44) which is integral with a second transmission shaft (52) which rotates the handwheel. (Machine-translation by Google Translate, not legally binding)

Description

[0001] DESCRIPTION

[0003] A sewing machine, adapted to close bags by sewing

[0005] Technical sector of the invention

[0006] The invention relates to a sewing machine of the type that uses a needle and a corresponding hook to create stitches, the machine being adapted so that such stitches can be made on a bag to close it, specifically determining a long bag tail.

[0008] Background of the invention

[0009] Portable electric sewing machines are currently available, which, being easy to hold with one hand, can be used to sew various items. One common type of this portable machine has two opposing heads attached to a common bridge: the first head contains the needle and the mechanical means for guiding its movement, which is operated by a connecting rod and crank mechanism; and the second head contains the hook and the mechanical means for guiding its movement, which is operated by a handwheel. The item to be sewn can be placed between the heads and the bridge.

[0011] These machines are equipped with an electric motor, mounted on the bridge, which, via a kinematic chain, drives the connecting rod-crank mechanism and the flywheel in a coordinated manner, thereby controlling the coordinated movement of the needle and hook. Because the machines are compact, the connecting rod-crank mechanism and the flywheel can be housed within the bridge, which also houses the aforementioned kinematic chain.

[0013] Usually, in order to balance the machines, the motor is supported on the bridge above the first head, and its output shaft connects inside the bridge to a pulley that drives or acts as a flywheel for the mechanical means that promote the movement of the hook, which is therefore located above the second head. This pulley also functions as the crank of the connecting rod-crank mechanism that drives the mechanical means that promote the movement of the needle, for which this connecting rod also extends inside the bridge, in this case from the area located above the second head to the area located above the first head.

[0014] These portable machines are capable of sewing various items. However, their compact size makes them unsuitable for sewing bags closed by stitching. More specifically, the distance between the needle and the bridge is so short that there is no room to accommodate a long bag tail.

[0016] This situation occurs, for example, when trying to use a portable machine of the type described above to close a bag with a bottom that contains an edible product. To ensure the bag fits snugly around the product so that it does not move around inside the bag once closed, it is advisable to sew along a portion of the bag close to the product. If the volume of the product is small compared to the usable volume of the bag, this stitching may be far from the bag opening, resulting in a bag tail—the portion of the bag between the stitching and the opening—that does not fit between the machine's heads and bridge.

[0018] Closing bags that store food products by sewing is a new or newly arisen need, of recent interest as a substitute for staples or metal auxiliary elements; and when wanting to apply this concept to close bags used for the specific delivery of food products to homes, where it is likely to use large bags to ensure that a large order fits in the bag, there can be long bag queues if the order is of small volume compared to the useful volume of the bag.

[0020] A first purpose of the invention is a machine that, either employing portable sewing machine heads or using such heads, may be suitable for closing bags by sewing, especially by determining long bag tails, and that may thus be used to close bags for home delivery of groceries.

[0022] Explanation of the invention

[0023] To overcome the drawbacks of the state of the art, the invention proposes a sewing machine according to claim 1.

[0025] The machine is adapted to close bags by sewing, creating long bag tails, and is of the type that uses a needle and a corresponding crochet hook to interlace the thread from a winding with the thread threaded through the needle, creating the stitch.

[0027] In a known form, the machine comprises a first and a second head, the first head having the needle and mechanical means for moving the needle driven by the reciprocating motion of a connecting rod foot of a crank-connecting rod mechanism; and the second head having the hook and mechanical means for moving the hook driven by the rotation of a handwheel.

[0029] In essence, the machine is characterized by comprising a rigid chassis that supports a first arm, a second arm and a bridge connecting the first and second arms, where the ends of the first and second arms support the first and second heads, respectively, opposed, offering a separation to admit a thickness of the bag to be closed by sewing and offering a distance D, between the needle and the bridge, which is greater than 200 mm making it capable of admitting a bag tail of similar length.

[0031] The machine also comprises a drive motor which, by way of a kinematic chain, moves the connecting rod-crank mechanism and the flywheel, it being particular that said kinematic chain is based on a pulley system comprising

[0033] - a first set of pulleys, with a first pulley rotating about an axle supported on the first arm and acting as the crank of the connecting rod-crank mechanism, the first pulley to which the connecting rod head of the connecting rod-crank mechanism is connected, said first pulley connecting to a second pulley that is integral with a first transmission axle supported and rotating on the bridge, and

[0035] - a second set of pulleys, with a third pulley attached to the first transmission shaft, where said third pulley connects inside the bridge with a fourth pulley that is attached to a second transmission shaft that drives the flywheel in rotation.

[0037] The first and second pulleys; and the third and fourth pulleys can be linked with conventional elements, for example, by means of first and second belts.

[0039] Advantageously, in any case, if you want to assemble a machine that offers a different length D, the first and second arms can be lengthened or shortened while preserving the kinematic chain, including the connecting rod-crank mechanism, only having to change the length of the element that links the first and second pulleys, for example a belt, adapting it to the new distance that separates the first and second pulleys.

[0041] Advantageously, both the first and second drive shafts can be selected to be driven in rotation by the motor output shaft, for example, by direct coupling with said output shaft.

[0043] In a preferred embodiment, the motor output shaft is directly coupled to the second drive shaft of the pulley system, with the fourth pulley then performing the function of the drive pulley of the pulley system.

[0045] In one variant of interest, the engine output shaft is axially aligned with the second drive shaft and with the flywheel.

[0047] In one embodiment, whatever transmission shaft is driven in rotation by the motor output shaft, the machine being oriented so that the needle is horizontal, the shaft of the first pulley and the first transmission shaft are parallel to each other and both horizontal; while the second transmission shaft is vertical.

[0049] Advantageously, the connecting rod will move in a plane that is parallel to the plane in which the component of the mechanical means that promote the movement of the needle moves, thus facilitating its connection with the connecting rod foot of the connecting rod-crank mechanism that drives said mechanical means.

[0051] In one embodiment of the machine, to increase its robustness, the first transmission shaft has two rotating support points on the bridge, between which the second and third pulleys are located hidden within the bridge; and the machine comprises a handle attached to the first transmission shaft located outside the bridge.

[0053] Brief description of the drawings

[0054] These and other features and advantages of the invention will become clearer from the detailed description that follows and with the help of the accompanying figures, of which:

[0056] Fig. 1 shows a portable sewing machine included in the state of the art;

[0058] Fig. 2 is a side view of a machine according to the invention, stripped of casing parts in order to show internal components that would otherwise not be visible;

[0059] Fig. 3 is a top detail view of the machine in Fig. 2; and

[0061] Fig. 4 is a side view, from the opposite side to that of Figure 2, of the same machine in this case provided with all the casing parts and other auxiliary elements.

[0063] Detailed explanation

[0064] Fig. 1 shows a conventional portable sewing machine 100’, of the type which, being graspable with one hand by the handle 101’, can be used to sew various articles.

[0066] The 100' machine is a commercially available machine, offered, for example, by La Canilla® under the name Rhino GK9-900. It is relevant to the operation of the machine that exemplifies the invention that this portable 100' machine has a first and a second head, 1 and 2, respectively, joined by a bridge 13'. The first head 1 mounts the sewing needle 1.1 and houses mechanical means for guided movement of said needle, mechanical means that are actuated by means of a connecting rod-crank mechanism; and the second head 2 mounts the corresponding hook (not visible) and mechanical means for guided movement of said hook, mechanical means that are actuated by means of a handwheel. The coordinated operation of the connecting rod-crank mechanism and the handwheel, naturally with the provision of thread, allows chain stitches to be made on an article placed and passed between the first and second heads 1 and 2.

[0068] The area of the article on which the stitches are to be made is limited, however, by the short distance D’ that separates the needle 1.1 from the bridge 13’ that holds the first and second heads 1 and 2.

[0070] In any case, for the coordinated operation of the connecting rod-crank mechanism that triggers the movement of the needle 1.1 and the handwheel that triggers the movement of the hook, the portable 100’ machine is equipped with an electric motor 5’. The motor 5’ is supported on the bridge 13’, following the first head 1, and by way of a kinematic chain entirely housed in the bridge 13’, the rotary motion of an output shaft of the motor 5’ is transmitted to both the connecting rod-crank mechanism and the handwheel.

[0072] In the specific machine 100’ the aforementioned output shaft of the motor 5’ is located above the first head 1 and is connected by belt and inside the bridge 13’ to a pulley that acts as a drive wheel for the hook located above the second head 2. This pulley also acts as the crank of the connecting rod-crank mechanism that triggers the movement of the needle 1.1, for which the connecting rod also extends inside the bridge 13’ in this case from the area located above the second head 2 to the area located above the first head 1.

[0074] As previously stated, because the distance D’ is short, the machine 100’ is not suitable for sewing bags closed, resulting in a long bag tail, as the long bag tail does not fit in the space provided by the machine 100’ between the needle 1.1 and the bridge 13’.

[0076] Figures 2 to 4 illustrate a machine 100 that solves this problem. The specific machine 100 makes advantageous use of the first and second heads 1 and 2 of the portable machine 100’.

[0078] Unlike the portable 100' machine, the 100 machine is designed to be supported by a pillar or securely attached to a wall or wall bracket. The first and second heads, 1 and 2, are positioned at a suitable height for an operator to place and slide the bag to be sealed between them. This allows the operator to hold the bag with both hands while stitching. The 100 machine can be operated, as is already known, with a foot pedal.

[0080] Machine 100 has a rigid chassis supporting a first arm 11 and a second arm 12, both long and absent in the portable machine 100’, and a bridge 13 connecting the first and second arms 11 and 12. The head 1 is supported at the end of the first arm 11; and the second head 2 is supported at the end of the second arm 12. As in the portable machine 100’, the first and second heads 1 and 2 are arranged opposite each other, providing an effective separation to accommodate a thickness of bag to be closed by sewing and offering, now, a long distance D (see Fig. 4) between the needle 1.1 and the bridge 13, to accommodate a long bag tail.

[0082] In the specific machine 100 that exemplifies the invention, the distance D is 400 mm. This distance D is significantly longer compared to the short distance D’ of 80 mm offered by the portable machine 100’. Naturally, taking advantage of the present invention, variants of the machine with other distances D can be constructed, as explained below.

[0084] Machine 100, like the portable machine 100’, is equipped with a single motor 5 supported on bridge 13. Since machine 100 utilizes the first and second heads 1 and 2 of a portable machine 100’, a kinematic chain is required in machine 100 that transmits exactly the same amount of motion to the mechanical means housed within the heads, which move the needle and hook, as was transmitted to them in the portable machine 100’.

[0086] Machine 100 overcomes this obstacle by applying a technical principle that is suitable regardless of the distance D chosen or required between needle 1.1 and bridge 13. Indeed, as will be understood, a change in distance D will not entail having to resize sensitive parts of this kinematic chain, such as a resizing of connecting rod 12 of the connecting rod-crank mechanism associated with needle 1.1.

[0088] Figures 2 and 3 show the technical principle implemented by machine 100.

[0090] As in the portable machine 100’, in machine 100 there is a kinematic chain that transmits the motion of the motor 5 to a connecting rod-crank mechanism and to a flywheel, in particular by way of a pulley system.

[0092] The aforementioned pulley system comprises in this case:

[0094] - A first set of pulleys, with a first pulley 41 rotating about an axis 41.1 supported on the first arm 11 and acting as the crank of the connecting rod-crank mechanism, to which is connected the head 12.2 of the connecting rod 12 of said connecting rod-crank mechanism which drives the mechanical means housed in the first head 1 that move the needle 1.1, wherein said first pulley 41 is linked by a first belt 412 to a second pulley 42, which is integral with a first transmission shaft 51 supported on the bridge 13; and

[0096] - a second set of pulleys, with a third pulley 43 also attached to the transmission shaft 51, the third pulley 43 being linked by a second belt 434 to a fourth pulley 44 attached to a second transmission shaft 52 which drives the handwheel that actuates the mechanical means housed in the second head 2 that move the hook.

[0098] It should be noted that in machine 100, the output shaft 5.1 of motor 5 is directly coupled to the second transmission shaft 52 of the pulley system, with the fourth pulley 44 acting as the drive pulley of the pulley system. Specifically, the aforementioned output shaft 5.1 of motor 5 is axially aligned with the second transmission shaft 52.

[0100] Advantageously, this allows for better access and/or facilitates operator supervision, as the motor 5 of machine 100 is located after the second head 2, leaving more space to approach the needle 1.1.

[0102] In the specific machine 100, the first and second pulleys 41 and 42 rotate around parallel axes that are oriented horizontally when the machine 100 is oriented so that the needle 1.1 follows a horizontal back-and-forth motion.

[0104] The first pulley 41 and crank 12 assembly can advantageously remain the same if the position of the pivot axis 41.1 of the first pulley 41 relative to the first head 1 is maintained, even if the distance D is to be changed. For example, if it is desired to increase the distance D, it is sufficient to lengthen the first arm 11 and the second arm 12 and provide a longer first belt 412 to connect the first and second pulleys 41 and 42 without altering in any way the movement transmitted to the foot 12.1 of the connecting rod 12, which is driven by the first pulley 41. It is not necessary to redesign or change the shape of the connecting rod 12 or the first pulley 41, which acts as the crank of the connecting rod-crank mechanism.

[0106] Even more advantageously, in machine 100 the connecting rod 12 moves in a vertical plane, which is parallel to the also vertical plane of movement of that component of the mechanical means housed in the first head 1 that moves the needle 1.1 and that receives the thrust from the foot 12.1 of the connecting rod 12. This component is a kind of rocker arm, of which only its connecting head 1.2 with the foot 12.1 of the connecting rod 12 is visible, in this case through an intermediate pin 1.3.

[0108] These movements in parallel planes simplify the transmission. Indeed, in the portable 100' machine, the connecting rod of the connecting rod-crank mechanism moves in a plane that is essentially orthogonal to the plane of movement of this rocker arm. This meant that the connecting rod had to incorporate ball couplings or equivalent solutions for its connection with the rocker arm head, which describes an arc of a circle inscribed in a plane orthogonal to that of the connecting rod's movement. It is precisely this circumstance and a solution requiring a ball coupling that is proposed in the portable sewing machine described in document CN205854646 (U).

[0110] On the other hand, in machine 100 the first transmission shaft 51 is horizontally oriented, that is orthogonal with respect to the second transmission shaft 52, which is vertically oriented.

[0112] Figure 3 shows how the connection between the third pulley 43 and the fourth pulley 44, which is integral with the second transmission shaft 52, is achieved, specifically by means of the second belt 434 with its crossed straight sectors. Providing teeth on these third and fourth pulleys 43 and 44 and on the second belt 434 for their corresponding meshing is sufficient for the second belt 434 to properly connect with the third and fourth pulleys 43 and 44. However, providing one or both of the third and fourth pulleys 43 and/or 44 with a groove is not ruled out.

[0114] Fig. 3 also serves to show that the first transmission shaft 51 has two pivoting support points 51.1, 51.2 on the bridge 13, between which the second and third pulleys 42, 43 are located; and that the machine 100 comprises a handle 6 integral with the first transmission shaft 51 located on an outer side of the bridge 13. This handle 6 serves to manually move the needle 1.1, for example, when the motor 5 is not a servomotor, and to position the needle 1.1 appropriately for threading with the thread 7.1.

[0116] Fig. 4 is a side view, from the opposite side to Fig. 2, of the same machine 100, which makes it possible to illustrate other auxiliary components of machine 100, for example, the support for the winding of the yarn 7.1. It should be noted that the provision of the first and second arms 11 and 12 allows this winding to be placed in a more suitable position for supplying yarn, in this case being able to place the winding support on the same first arm 11 that supports the first head 1.

[0118] Although not shown in the drawings, the expert will understand that the chassis can support parapets, panels or other elements to cover the moving parts and pulley system, preferably in a detachable manner to allow access to this pulley system for inspection or maintenance.

[0119] Furthermore, although the invention has been exemplified by a machine 100 that utilizes or employs the same heads as a specific portable machine 100’, it is evident that heads not taken from or used on a portable sewing machine or any other machine can be employed. A machine such as the invention can be manufactured with its own heads without sacrificing the advantages of the invention. That is, a machine can be built with a longer or shorter distance D using the same connecting rod-crank mechanism to drive the mechanical means that move the needle; and the same handwheel to drive the mechanical means that move the hook.

Claims (5)

1. CLAIMS 1.- A sewing machine (100), adapted for closing bags by sewing, creating long bag tails, of the type that uses a needle (1.1) and a corresponding hook (2.1) to interlace the thread (7.1) of a bobbin (7) with the thread threaded on the needle (1.1), creating the stitch, the machine comprising a first and a second head (1, 2), the first head (1) with the needle (1.1) and mechanical means for moving the needle driven by the reciprocating motion of a foot (12.1) of a connecting rod (12) of a connecting rod-crank mechanism, and the second head (2) with the hook and with mechanical means for moving the hook driven by the rotation of a handwheel, the machine being characterized in that it also comprises a rigid chassis, which supports a first arm (11), a second arm (12) and a bridge (13) joining the first and second arms, where the ends of the first and second arms (11, 12) support the first and second heads (1, 2), respectively, opposed, offering a separation to admit a thickness of the bag to be closed by sewing and offering a distance D, between the needle (1.1) and the bridge (13), which is greater than 200 mm capable of admitting a bag tail of similar length, and a drive motor (5) which, via a kinematic chain, moves the connecting rod-crank mechanism and the flywheel, where said kinematic chain is based on a pulley system comprising - a first set of pulleys, with a first pulley (41) rotating about an axle (41.1) supported on the first arm (11) and acting as the crank of the connecting rod-crank mechanism, the first pulley (41) being connected to the head (12.2) of the connecting rod (12) of the connecting rod-crank mechanism, said first pulley (41) connecting to a second pulley (42) which is integral with a first transmission shaft (51) supported and rotatable on the bridge (13), and - a second set of pulleys, with a third pulley (43) also integral with the first transmission shaft (51), where said third pulley (43) connects inside the bridge (13) with a fourth pulley (44) that is integral with a second transmission shaft (52) that drives the flywheel in rotation. 2. The sewing machine (100) according to claim 1, characterized in that the motor (5) has an output shaft (5.1) and in that said output shaft (5.1) is directly coupled with the second transmission shaft (52) of the pulley system, the fourth pulley (44) performing the function of driving pulley of the pulley system. 3.- The sewing machine (100) according to claim 2, characterized in that the output shaft (5.1) of the motor (5) is axially aligned with the second transmission shaft (52) and with the handwheel. 4. The sewing machine (100) according to any one of the preceding claims, characterized in that, the machine being oriented so that the needle (1.1) is horizontal, the axis (41.1) of the first pulley (41) and the first transmission axis (51) are parallel to each other and both horizontal; while the second transmission axis (52) is vertical. 5. The sewing machine (100) according to any one of the preceding claims, characterized in that the first transmission shaft (51) has two rotating support points (51.1, 51.2) on the bridge (13), between which the second and third pulleys (42, 43) are located hidden within the bridge (13); and in that the machine comprises a handle (6) attached to the first transmission shaft (51) located outside the bridge (13).