EP1719830B1

EP1719830B1 - Sewing machine with a base designed to hold interchangeable means for sewing fabrics using different types of stitch

Info

Publication number: EP1719830B1
Application number: EP06113518A
Authority: EP
Inventors: Carlo VI.BE.MAC. S.p.A. Guerreschi
Original assignee: Vi Be Mac SpA
Current assignee: Vi Be Mac SpA
Priority date: 2005-05-06
Filing date: 2006-05-04
Publication date: 2010-02-10
Anticipated expiration: 2026-05-04
Also published as: DE602006012135D1; ES2339965T3; EP1719830A2; CN1880539A; EP1719830A3; JP2006312041A; KR101294466B1; TWI364468B; CN1880539B; ITVR20050056A1; TW200643251A; ATE457379T1; KR20060115604A

Abstract

This is a sewing machine (1), preferably of the industrial type, with a base (2) designed to mechanically sew two pieces of fabric together using different types of sewing stitch by simply and quickly replacing a few components housed in the base itself (2).

Description

This industrial invention patent application proposes a base for a sewing machine, preferably of the industrial type, designed to mechanically sew two pieces of fabric using different types of sewing stitch by simply and quickly replacing a few components of which it is composed.
We have, consequently, a component for sewing machines with the particular feature of being able to sew two pieces of fabric by at least two different types of sewing stitch thanks to a fast and easy exchange of a few components.
As is known sewing machines that, in their most common form, are machines that mechanically sew together two pieces of fabric, in the industrial world are conceived with various structural techniques depending on the various operations they are destined to perform.
There are, for example, single needle or multiple needle units used to stitch garments such as jeans or casual pants in general, work garments and shirts or many other types.
These industrial sewing machines, according to their different versions, may sew different types of fabrics such as on the yokes, front or rear pants crotch, leg riveting or for the greatest variety of applications and are available in different versions for light or heavy fabrics.
Normally all these versions are therefore equipped with an upper head where the needle is positioned, a system for feeding the pieces of fabric to sew and a base, positioned below the upper head, comprising means that, together with the needle, create the sewing stitch.
The rotary motion in the upper head, powered by a shaft connected to a drive motor, is converted, through an eccentric, into reciprocating motion and then transferred to the needle-holder support. A fabric-pressure foot is also present on this upper head, near the needle, which functions to press the pieces of fabric to be sewn down towards the lower base.
The fabric feed system generally comprises special means that act on the fabrics to be sewn, moving them in one direction.
The base, positioned below the upper head, includes at least one hook that allows to terminate, together with the needle, the sewing stitches.
Obviously all the components described above, having both rotary and translational movements, perform movements in synchrony with each other. Special importance in design and manufacture of sewing machines obviously goes to the type of sewing stitch to be made.
Of course, each different sewing stitch requires different components and different movements by these components. The consequence of this is the use of different sewing machines for different sewing stitches.
For example to make a knotted stitch according to known technique the machine must have a special hook with continuous rotary movement and with synchrony calling for a translational needle movement that corresponds to two 360° hook rotations.
On the other hand to make a chain stitch the machine must have a hook with a different shape from the hook for the knotted stitch, with reciprocating rotary and/or translational movement and with synchrony calling for one needle translational movement corresponding to one movement by the hook itself.
In addition the need to give the hook reciprocating motion forces manufacturers to make machines with structures that are rather different from the structures of machines used to make knotted stitches.
Another difference between these two types of machine is in the fact that while the knotted stitch machine has a bobbin with the thread inserted inside the hook the chain stitch machine has diverse mechanisms that are even installed external to the machine.
These important and substantial differences between the two different types of machine are due to the great diversity in form and creation of the knotted stitch, illustrated in figure A and the double-chain stitch, illustrated in figure B.
According to known technique, therefore, we necessarily have two different types of sewing machine for the two different types of sewing stitch.
This involves a considerable expense for the customer or for businesses in the textile industry who are required to offer an increasingly flexible and versatile service in function, primarily of the speed of changes in fashions.
GB-A-2175616 discloses a sewing machine having a base constructed of two modules having coupling means permitting one of said modules to be removed from the other so that different sewing devices can be substituted to change the type of stitch. In particular such a sewing machine comprises a base module provided for forming double chain-stitches.
The scope of the invention that is the object of this patent application is to overcome all the above-mentioned problems as well as others thanks to creation of a single machine which, by fast and simple interchange of just a few parts, can work alternatively to make knotted stitches and double-chain stitches.
These scopes and advantages are all achieved, according to the invention, by a sewing machine according to claim 1.
The machine, configured in this way, achieves advantageous creation of specific means can be alternated depending on the desired type of stitch.
The object of this invention patent therefore eliminates the need to purchase two different machines and generates great economic savings. In addition the sewing machine in question makes it possible to exchange the means designed for the different types of stitch in a fast and simple manner. Other features and details of the invention can be better understood from the following description, given as a non-limiting example, as well as from the attached drawings where:

fig. A shows the structure of the knotted stitch;
fig. B shows the structure of the double-chain stitch;
fig. 1 is an axonometric view of a sewing machine which includes the base that is the object of this invention patent;
fig. 2 is a front axonometric view from above of the base assembled using components designed to sew with the knotted stitch;
fig. 3 is a side axonometric view from above of the base in figure 2;
fig. 4 is an exploded side axonometric view from above of the base in figure 2;
fig. 5 is a front axonometric view from above of the base assembled using components designed to sew with the chain stitch;
fig. 6 is a side axonometric view from above of the base in figure 5;
fig. 7 is an exploded side axonometric view from above of the base in figure 5.

In the attached illustrations number 1 indicates a sewing machine comprising base 2, object of this invention patent, and basically all the components designed for it to work properly such as, for example, upper head 4, fabric movement device 3 and base 2.
Base 2, in particular, includes support structure 23 designed to house the different movement and sewing means that make the two different types of sewing stitch: the knotted stitch and the double-chain stitch.
Structure 23 of base 2, as shown in figures 2, 3, 4 in one possible form, houses, in a cylindrical perforation, bush 6 which, once inserted in structure 23, remains stationary with respect to the structure. Said bush 6 has longitudinal hole 24 in which shaft 7 is inserted and which is connected at one of its end to hook 5. These components are kept in a stable position by at least one shim ring 8.
In addition, gear 9 is fastened to the end of shaft 7 opposite the end where hook 5 is positioned. This gear is meshed by suitable means to main shaft 12 that powers shaft 7 and, consequently, hook 5.
It is therefore clear how, when main shaft 12 performs continuous rotary motion, shaft 7, just like hook 5, performs continuous rotation.
Base 2, described as above, permits, in tune with the movements of the sewing machine needle, to make the knotted type of stitch where, to every translational movement of the needle, there is a corresponding two full turn rotation by hook 5.
When the need arises to make double-chain stitches then these previously described components can be removed from base 2: hook 5, shim ring 8, bush 6, shaft 7 and gear 9. These components are replaced by new means which are combined so as to sew with a double-chain stitch.
Base 2, in the new configuration illustrated in figures 5, 6 and 7, calls for inserting cylindrical bush 17 in the perforation in structure 23. This bush has longitudinal hole 25 positioned eccentrically with respect to the axis of the bush itself.
Shaft 18 is placed inside said hole 25. One of the shaft's ends carries shim ring 16, hook bush 15, needle-guard 14 and hook 13, made integral with hook bush 15 using special coupling means such as, for example, screws.
The other end of shaft 18 is coupled to main shaft 12 using special means that give shaft 18 reciprocating rotary motion. This, more specifically, is achieved by main shaft 12 that performs continuous rotation and is coupled with eccentric 19 positioned inside the hole of connecting rod 20 the end of which, opposite eccentric 19, is connected to lever 21 which in its turn is fastened in a fixed manner to shaft 18.
Thanks to these levers, the continuous rotary motion of main shaft 12, is transformed into reciprocating rotary motion that is imparted to shaft 18 and, consequently, also to hook 13. This is a type of motion that is designed to perform movements of the type that technique requires to make the chain stitch.
In this case as well the means just described are fixed to structure 23 on base 2 using clamping components and assembly screws.
We can also note the presence of mechanisms designed to open the loop to make the chain and, more specifically, shaft 11 which can, in any case, remain mounted on base 2 even in the presence of components designed to make the knotted stitch.
The sewing machine, object of this invention patent, therefore presents base 2 comprising fixed means such as, for example, structure 23, on which components designed to make knotted stitches (hook 5, bush 6, shaft 7, shim ring 8, gear 9) can be alternated with components designed to make double-chain stitches (hook 13, needle guard 14, hook bush 15, shim ring 16, bush 17, shaft 18, lever 21, connecting rod 20, eccentric 19).
In particular the moving parts that are interchanged, to make both the knotted stitch and the double-chain stitch, are powered by the same main drive shaft 12.
Thanks to the sewing machine in question, it is consequently possible to make two different types of sewing stitches - the knotted stitch and the double-chain stitch as illustrated in figures A and B - by quickly and simply replacing a few parts which, according to known technique, should on the contrary be performed by different sewing machines.
In addition dismantling and reinstalling the various parts on base 2 can be performed by any technician in the sector without specialized expertise.
A technician in the sector may forecast modifications or variations within the scope of protection of the appended claims.

Claims

Sewing machine comprising a main shaft (12) and a base (2) shaped so as to permit insertion of means (5, 6, 7, 8, 9) designed to sew by making knotted stitches in an alternate manner with means (13, 14, 15, 16, 17, 18, 21, 20, 19) designed to sew by making double-chain stitches, at least one of these means (5, 6, 7, 8, 9, 13, 14, 15, 16, 17, 18, 21, 20, 19) being connected to the main shaft (12), said main shaft (12) driving these means (5, 6, 7, 8, 9, 13, 14, 15, 16, 17,18, 21, 20, 19),
characterized by the fact that main shaft (12) is coupled by gears (9) to shaft (7) the end of which is fastened to hook (5), said shaft (7) passing through a shim ring (8) and in a hole (24) of a bush (6) inserted in base (2), these means (7, 9) generating a continuous rotary motion of hook (5) so as to make a knotted type of stitch.
Sewing machine according to claim 1 characterized by the fact that main shaft (12) is coupled by levers (19, 20, 21) to a shaft (18) the end of which is fastened, by support (15), to needle-guard (14) and hook (13), said shaft (18) passing through a shim ring (16) and in a hole (25) of a bush (17) inserted in base (2), these means (18, 19, 20, 21) generating reciprocating rotary motion by hook (13) so as to create a double-chain type of stitch.
Sewing machine according to claim 2 characterized by the fact that an eccentric (19), inserted in the hole of a connecting rod (20), which is in its turn connected to a lever (21) firmly joined to shaft (18), is coupled to main shaft (12) so that the continuous rotary motion of main shaft (12) is transformed into reciprocating rotary motion by shaft (18).
Sewing machine according to claims 2, 3 characterized by the fact that bush (17) is eccentric.
Sewing machine according to the previous claims characterized by the fact that on base (2) means (11) are present, both in the configuration for the knotted stitch and in the configuration for the double-chain stitch, designed to open the loop to form the chain stitch, these means being active only in the configuration designed to make the chain stitch.