The present invention relates to an oil discharge device of an upper looper mechanism in an overlock sewing machine, and more particularly to an oil discharge device of lubricating oil provided for preventing soiling of thread or cloth due to scatter of lubricating oil supplied on an upper looper holder from a lubricating device along with ascending and descending motion of the upper looper holder, in an upper looper mechanism of overlock sewing machine comprising an upper looper base affixed to a sewing machine frame, a circular columnar upper looper holder guide rotatably mounted on the upper looper base, an upper looper holder slidably penetrating through the upper looper holder guide, cooperating with the upper looper shaft coupled by a link mechanism, and ascending and descending while inclining as being guided by the upper looper holder guide, and an upper looper attached to the upper looper holder projecting from the upper looper holder guide.
Upper looper mechanisms in overlock sewing machine to solve the problem of soiling of cloth by upward scattering of lubricating oil sticking to the upper looper holder when the upper looper holder ascends and descends, are known. In one of such known mechanisms, an O-ring is provided in an upper looper holder guide in which an upper looper slidably penetrates, the upper looper holder passes through the O-ring, and the lubricating oil sticking to the upper looper holder is scraped off by the O-ring when the upper looper holder ascends and descends, so that the lubricating oil may not scatter above from the upper looper holder guide (for example, Japanese Laid-open Utility Model No. H3-30975).
In other upper looper mechanism, the lubricating oil sticking to the upper looper holder is scraped off by the upper end of the through-hole in the upper looper holder guide when the upper looper holder ascends and descends, and by the action of gravity of the lubricating oil itself, the negative pressure induced in a circular oil groove at the outside of the upper looper holder due to rotary motion of the upper looper holder guide, and the action of centrifugal force by rotation of upper looper holder guide, the lubricating oil is attracted into the circular oil groove and is collected in a lower inner part of the sewing machine frame by way of an oil relief hole (for example, Japanese Laid-open Patent No. H9-66184).
As feeding means of lubricating oil into necessary parts such as upper looper mechanism and needle bar mechanism of an overlock sewing machine, a trochoid pump is widely used. For example, an inter lock stitch machine such as a cylinder bed sewing machine employs a two-layer type trochoid pump consisting of a first pump body and a second pump body driven by a pump shaft cooperating with a sewing machine main shaft and linked vertically each other, and in this lubricating oil feeding and discharging device, the lubricating oil collected in an oil pan provided beneath the sewing machine bed is sucked into the first pump body, and is supplied into necessary mechanical parts such as needle bar mechanism and looper mechanism in the sewing machine, and the lubricating oil left over in the bed or arm upper jaw is sucked and collected by the second pump body (for example, Japanese Utility Model Publication No. H3-31272).
However, in the upper looper mechanism disclosed in Japanese Laid-open Utility Model No. H3-30975, the upper looper holder guide is complicated in structure in order to install the O-ring, so that the cost is high. In addition, the O-ring becomes worn by vertical motion of the upper looper holder, and when replacing the worn O-ring, peripheral members must be dismounted including the upper looper holder guide, and the replacement work takes much time and toil.
In the upper looper mechanism disclosed in Japanese Laid-open Patent No. H9-66184, such problem does not exist because O-ring is not used, but the lubricating oil scraped off by the upper edge of the through-hole of the upper looper holder guide cannot be collected sufficiently only the its own gravity or the negative pressure in the circular oil groove induced by rotation of the upper looper holder and the action of rotary centrifugal force. As a result, the residual portion of the lubricating oil is left over around the upper edge of the through-hole and the remaining lubricating oil may scatter upward by the vertical motion of the upper looper holder to soil the thread or cloth.
It is hence the first object of the invention to present an oil discharge device provided in an upper looper mechanism of an overlock sewing machine capable of completely solving the problem of soiling of thread or cloth due to scattering of lubricating oil above the upper looper holder when the upper looper holder ascends and descends, and it is the second object thereof to present an oil discharge device of upper looper mechanism of a compact trochoid pump design as a oil feeding and discharging device for collecting and supplying the lubricating oil, in addition to the first object.
An upper looper mechanism in an overlock sewing machine of the invention comprises an upper looper base affixed to a sewing machine frame, a circular columnar upper looper holder guide rotatably mounted on the upper looper base, an upper looper holder slidably penetrating through the upper looper holder guide in the diametral direction, coupled to an upper looper shaft by a link mechanism, cooperating with an upper looper shaft, and ascending and descending while inclining as being guided by the upper looper holder guide, and an upper looper attached to the upper looper holder projecting from the upper looper holder guide.
The lubricating oil discharge device in one aspect of the invention is intended to prevent soiling of thread and cloth due to scatter the lubricating oil supplied to the upper looper holder of the upper looper mechanism described above from a feeding device along with the vertical motion of the upper looper holder, in which the upper looper holder guide has an oil discharge hole opened in the periphery of an upper end of a through-hole for passing the upper looper holder, and the lubricating oil is sucked from the opening of the oil discharge hole by a pump driven in cooperation with the sewing machine main shaft, and is collected through the oil discharge hole.
According to the invention, the lubricating oil near the oil discharge hole is sucked by the pump and discharged by force.
The pump used in the invention is not particularly specified as far as the lubricating oil can be sucked from the oil discharge hole and discharged by force. For example, gear pump or trochoid pump mentioned above may be used.
In other aspect of the invention, a passage hole is formed in the sewing machine frame for discharging oil, and one end of the passage hole is connected to the oil discharge hole and other end is connected to the pump by way of an oil discharge pipe.
According to the invention, the lubricating oil is sucked and forced to discharge by the pump by way of the passage hole and oil discharge pipe.
In a different aspect of the invention, a spot facing is formed at the side of the upper looper holder guide. In the spot facing, An oil discharge hole is formed and also an oil wick is inserted, and a suction port of a passage hole connected to the pump is connected to this oil wick.
In a different aspect of the invention, instead of forming said spot facing at the side of the upper looper holder guide, the spot facing is formed in the frame of the sewing machine bed which the side of the upper looper holder guide contacts. the oil discharge hole formed in the upper looper holder guide is connected to an oil wick inserted in the spot facing, and a suction port of a passage hole connected to the pump is opened in the spot facing.
The upper looper holder guide oscillates around the axial direction along with vertical motion of the upper looper holder, and hence the opening of the oil discharge hole is dislocated, and it is deviated from the suction port of the passage hole, but since the spot facing and the oil wick inserted in the spot facing are interposed, the opening of the oil discharge hole stays within the range of the spot facing, so that the oil discharge hole and oil discharge route can be connected.
In a different aspect of the invention, the oil discharge hole is opened in an edge at the upper end of a through-hole of the upper looper holder guide.
According to the invention, the lubricating oil sticking to the upper looper holder can be sucked and discharged by force.
In a different aspect of the invention, the oil discharge hole is composed of a first oil discharge hole opened in an edge at the upper end of a through-hole of the upper looper holder guide, and a second oil discharge hole communicating with the first oil discharge hole, and the opening of the second oil discharge hole is exposed from the upper looper base only when the upper looper holder reaches the top dead center or the bottom dead center.
According to the invention, the lubricating oil sticking to the upper looper holder is always sucked and discharged from the opening of the first oil discharge hole. The opening of the second oil discharge hole is exposed from the upper looper base only when the upper looper holder reaches the top dead center or the bottom dead center, and the lubricating oil collected in the exposed portion of the top of the upper looper holder guide is discharged.
The opening of the second oil discharge hole may be always exposed, but when designed to be exposed only when the upper looper holder is at the top dead center or the bottom dead center as in the invention, when the upper looper holder is at other position than the top or the bottom dead center, the opening of the second oil discharge hole is clogged by the upper looper base, and the negative pressure of the first oil discharge port is raised so that the suction action is enhanced.
In a different aspect of the invention, the upper looper holder guide has a pass hole penetrating through the upper looper holder guide formed in the axial direction, and a groove formed in the axial direction on the outer circumference sliding with the upper looper base, and the first and second oil discharge holes are branched by the pass hole, and the second oil discharge hole is opened to the groove, and the one end of said pass hole is connected to an oil wick inserted in the spot facing formed in the sewing machine frame contacting with the side of the upper looper holder guide or the side of the upper looper holder guide.
According to the invention, if the opening of the through-hole is dislocated by oscillation of the upper looper holder guide, it is connected to the oil wick, and the lubricating oil is sucked in a wide range of the overall length of the groove, so that the oil can be discharged by force.
In a different aspect of the invention, the pump is a two-layer trochoid pump consisting of a first pump body and a second pump body being linked vertically each other and driven by a pump shaft rotating in cooperation with the sewing machine main shaft, and the upper first pump body discharges oil while the lower second pump body supplies oil.
According to the invention, using the two-layer trochoid pump, by discharging oil by the first pump body and supplying oil by the second pump body, the lubricating oil can be supplied and discharged, and by using the trochoid pump, a plurality of suction ports can be provided, and therefore the lubricating oil left over in different places such as the bed and arm upper jaw can be sucked and collected by one pump body.
In a different aspect of the invention, the casing composing a trochoid pump and having a port for oil supply or oil discharge is attached to the sewing machine frame of the bed.
In the trochoid pump disclosed in Japanese Utility Model Publication No. H3-31272, the mounting plate of the trochoid pump to the frame is fixed, but in the present invention, the casing composing the trochoid pump is directly fixed to the sewing machine frame, and mounting plate is not needed, and bulkiness in the vertical direction is smaller than in the trochoid pump disclosed in Japanese Utility Model Publication No. H3-31272, so that a compact design is realized.
In a different aspect of the invention, the discharge port of the first pump body is a discharge groove formed in the top of the casing of the first pump body or the second pump body.
According to the invention, the structure of the discharge port of the first pump body is simplified, and the cost is reduced.
In a different aspect of the invention, both ends of the discharge groove are opened.
According to the invention, oil is discharged from both ends of the discharge groove, and oil discharge is very smooth.
Other features and effects of the present invention will be more clearly understood in the following detailed description of the embodiments by those skilled in the art. It must be, however, noted that the technical scope of the present invention is not limited to the embodiments and the accompanying drawings alone.
As shown in
In FIG. 2 and
A space D, in which the upper looper lever 16 and the lower parts of upper looper holder 12 are disposed, is closed by a cover 50 at the front side. In the frame 2, a through-hole 52 is formed, and its upper end is opened to the space D and lower end is opened to an oil pan 51.
To supply oil into the lubricating parts of the upper looper mechanism B, the frame 2 of the sewing machine bed A has a hollow oil feed pin 19 with an upper opening as shown in FIG. 2 and
Further, by the ascending and descending motion of the upper looper holder 12, part of the lubricating oil contacting with the hinge pin 21 is sprayed like mist in the space D and sticks to the lower parts of the upper looper holder 12 and the upper looper holder guide 7. On the other hand, the lubricating oil sticking to the outer wall composed the space D, that is, the frame 2 and cover 50 is returned to the oil pan 51 by way of the through-hole 52.
The lubricating oil thus sticking to the upper looper holder 12 contacts with the oil wick 9 provided in the upper looper holder guide 7 when the upper looper holder 12 ascends and descends, and is impregnated in the oil wick 9. As a result, the whole circumference of the upper looper holder 12 is coated with the lubricating oil by the oil wick 9, and slides in the upper looper holder guide 7.
The lubricating oil sticking to the upper looper holder guide 7 is attracted into the sliding surface with the upper looper base 4 along with rotation of the upper looper holder guide 7.
The lubricating oil sticking to the upper looper holder 12 projecting from the upper looper holder guide 7 is scraped off by the edge at the upper end of the through-hole 11 when the upper looper holder 12 descends, and is collected in the longitudinal hole 6 around the upper end of the through-hole 11, and the lubricating oil staying on the sliding parts between the inner circumference of the lateral hole 5 of the upper looper base 4 and the outer circumference of the upper looper holder guide 7 is also scraped by the edge at the intersection of the lateral hole 5 and longitudinal hole 6 by rotation of the upper looper holder guide 7, and is collected in the longitudinal hole 6 around the upper end of the through-hole 11. In order to suck the lubricating oil collected around the upper end of the through-hole 11 and discharge by force, the upper looper holder guide 7 is configured as described below, and an oil supply and discharge device C of lubricating oil is provided. They are described below.
As shown in FIG. 5 and
The oil supply and discharge device C of lubricating oil is, as shown in
The casing 36 has, as shown in
The first pump body 33 and second pump body 34 are same as the conventional pump as disclosed, for example, in Japanese Utility Model Publication No. H3-31272, except that the shape of the casings 35, 36 is different, and that the oil discharge port 38 of the first pump body 33 and oil discharge port 43 of the second pump body 34 are both disposed at the front side, and further than a mesh filter 44 is provided in the second pump body 34.
This device is thus configured, and as the first pump body 33 is driven, the first and second oil discharge holes 27 and 28 are evacuated to a negative pressure, so that the oil is sucked. Of the two oil discharge holes 27, 28, the opening of the first oil discharge port 27 contacts with the projecting portion of the upper looper holder 12 right after projecting from the upper looper holder guide 7, and the lubricating oil sticking to the upper looper holder 12 is always sucked and discharge by force during driving operation of the sewing machine. Until the upper looper holder 12 reaches the top dead center or the bottom dead center, oil is discharged by force only from the first oil discharge hole 27, and the negative pressure of the first oil discharge hole 27 is heightened, but when the upper looper holder 12 reaches the top dead center or the bottom dead center, one opening of the right and left second oil discharge holes 28 is exposed in the longitudinal hole 6 of the upper looper base 4 and the upper looper holder guide 7, and by the negative pressure of the second oil discharge hole 28, the lubricating oil collected in the longitudinal hole 6 of the upper looper base 4 and the upper looper holder guide 7 is sucked, and discharged by force.
In this preferred embodiment, the oil discharge hole is composed of the first oil discharge hole 27 and the second oil discharge hole 28, and the second oil discharge hole 28 is exposed from the longitudinal hole 6 of the upper looper base 4 only when the upper looper holder 12 reaches the top dead center or the bottom dead center, and the spot facing 24 is formed in the upper looper holder guide 7, but the second oil discharge hole 28 may be exposed from the longitudinal hole 6 if the upper looper holder 12 is not at the top dead center or the bottom dead center. Either one of the first oil discharge hole 27 and second oil discharge hole 28 may be omitted. Further, the spot facing 24 may be formed in the frame 2 of the sewing machine bed A, and the suction port 39a of the passage hole 39 may be opened in the spot facing 24 formed in the frame 2.
Also, the first pump body 33 and the second pump 34, instead of trochoid pumps, may be used other pumps such as gear pumps.
Number | Date | Country | Kind |
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2002-359678 | Dec 2002 | JP | national |
Number | Name | Date | Kind |
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3883262 | Schmedtkord et al. | May 1975 | A |
3981257 | Kelly | Sep 1976 | A |
4348970 | Robinson et al. | Sep 1982 | A |
5088427 | Takagi et al. | Feb 1992 | A |
Number | Date | Country |
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3-30975 | Mar 1991 | JP |
3-31272 | Jul 1991 | JP |
9-66184 | Mar 1997 | JP |
2002217667 | Feb 2004 | JP |
Number | Date | Country | |
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20040118329 A1 | Jun 2004 | US |