1. A method for longitudinal orientation of tubular knitted elements such as socks (2), knee socks or the like, said tubular elements having two respective ends as a tip portion (2 ) and a band portion, comprising the steps of:
preliminarily stretching the sock (2) in a duct (3) of orientation, whereby the sock (2) is present in the duct (3) of orientation with its two ends aligned longitudinally;
detecting by means of sensors (13) the position of an end that is either a tip portion (2) or a band portion;
after the detecting step, conveying the sock (2) in the duct (3) in a direction according to which the position is known of the band portion with respect to the tip portion (2), whereby before the introduction of the sock (2) in a loading duct (3) a step is provided oat, inversion of the sock (2) if the band portion is not oriented in the chosen direction, or a step of rejection.
2. Method according to claim 1, wherein for conveying the sock (2) an air flow is selectively sent in the duct (3) of orientation whereby the sock (2) proceeds in the duct (3) in either one or the other direction and is then deviated into a loading duct (3) so that it is conveyed in the loading duct (3) with band portion, and tip portion (2) oriented in a predetermined way by said sensor means.
3. Method according to claim 1, wherein the preliminary stretching step of the sock (2) is carried out by means of an air flow after preliminarily grasping a first end thereof, whereby the second end engages said sensor means.
4. Method according to claim 1, wherein for carrying out said detecting step a mechanical dragging step is provided (12) starting from its second end through said sensors (13) that carry out a scanning of at least part of the first end thereof.
5. Method according to claim 1, wherein said sensors carry out a contemporaneous scanning of said sock upstream and downstream of said dragging means (12), whereby the profiles can be at the same time detected of said first and second end and a comparison between them is made.
6. Method according to claim 4, wherein after said preliminary stretching step the sock extends with said second end between dragging means (12), the latter pinching said second end and dragging the sock (2) after that the air flow has stopped, the first end being left free and the sensor means (13) scan the sock. (2) in the portion set between said first and said second end.
7. Method according to claim 5, wherein for a correct scanning the sock (2) is pressed between the sensor moans (13) during the dragging step, for stretching any possible folds and improving the scanning conditions.
8. Method according to claim 1, wherein the sock (2) after said preliminary stretching step moves substantially in a plane, said sensors (13) scanning at least a portion of said sock (2) orthogonally to said plane, whereby said sensors recognise the plan profile of said tip portion (2) or of said band portion.
9. Method according to claim 1, wherein the sock (2) after said preliminary stretching step moves substantially in a plane, said sensors (13) scanning at least a portion of said sock (2) parallel to said plane, whereby said sensors recognise different heights of the side profile of said tip portion (2) or of said band portion.
10. Apparatus for longitudinal orientation of a sock (2) according to the one of the previous claims, comprising:
a duct (3) of orientation wherein said sock (2) is present with its two ends aligned longitudinally,
sensor means (13) for scanning the profile of said sock (2) at one end of said sock (2) and determining whether it is a tip portion (2) or a band portion,
means for creating selectively an air flow in said duct (3) of orientation that drags said sock (2) in a predetermined way and brings it in a loading duct (3),
means for deviating said sock (2) so that it enters said loading duct (3) with tip portion (2) and band portion oriented in a predetermined way .
11. Apparatus according to claim 10, wherein mechanical dragging means (12) of the sock (2) are also provided along said duct (3) of orientation and, through said sensor means (13), the latter detecting the profile of at least one part of said sock (2) at the passage controlled by said dragging means (12).
12. Apparatus according to claim 11, wherein said dragging means (12) comprise at least two dragging rollers that pinch said sock (2) and convey it so that at least a portion thereof passes through said sensor means (13).
13. Apparatus according to claim 11, wherein said sensor means are grouped as first sensors upstream of said dragging means (12) and seconds sensors downstream said dragging means (12), whereby the profiles can be at the same time measured of said first and second end and a comparison between them is made.
14. Apparatus according to claim 12, wherein said sensor means (13) comprise a head that pushes said sock (2) against a counter-surface belonging to said duct (3), whereby said sock (2) is dragged between said head and said counter-surface for stretching any possible folds and for allowing a correct detection of its profile.
15. Apparatus according to claim 12, wherein means are provided for stretching the sock (2) in said duct (3) comprising:
means for grasping a first end thereof leaving the second end free,
means for creating an air flow from the first to the second end;
means for blocking said dragging means (12) against said second end stretched by said air flow, said dragging means (12) dragging the sock (2) after that the air flow has stopped, the first end being left free, the sensor means (13) scanning at least one part of said sock that crosses them.
16. Apparatus according to claim 10, wherein in said duct (3) of orientation two grids are provided (6, 7) movable between an open position and a closed position, at each grid (6, 7) grasping means being provided (8, 9), the sensor means (13) and the dragging means (12) being arranged between said two grids (6, 7).
17. Apparatus according to claim 10, wherein said sensor means (13) comprise an array of sensors (13) with a density that allows a sufficient definition of the contour of at least a portion of the sock (2).
18. Apparatus according to claim 10, wherein said sensor means (13) are chosen among: optical sensors (13), mechanical sensors (13), pneumatic sensors (13), electrical sensors (13).
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A radio frequency switch comprising:
first, second and third transmission lines for forming first, second and third ports; and
first, second and third slot line pattern portions connected to one another, for signal transferring with the first, second and third transmission lines,
wherein the first slot line pattern portion includes a slot line pattern for providing a signal received from the first transmission line to a connection to the other slot line pattern portions, and a switching circuit installed at a predetermined position of the slot line pattern, for blocking a signal by shorting the gap of a slot line according to an external control signal, and
wherein the second slot line pattern portion includes a loop slot line formed by a first half loop slot line and a second half loop slot line, for signal transferring between a portion thereof and the second transmission line, a second sub-slot line for providing a signal received from the connection to the other slot line pattern portions to the second transmission line through the loop slot line, and a switching circuit installed at a predetermined position of slot line pattern, for blocking a signal by shorting the gap of a slot line according to an external control signal.
2. The radio frequency switch of claim 1, wherein the slot line pattern of the first slot line pattern portion comprises:
a loop slot line formed by a first half loop slot line and a second half loop slot line, for signal transferring between a portion thereof and the first transmission line;
a first sub-slot line for providing a signal received from the loop slot line to the connection to the other slot line pattern portions.
3. The radio frequency switch of claim 2, wherein the switching circuit of the first slot line pattern portion comprises:
first and second switching devices installed in the vicinity of a connection between the first half loop slot line and the first sub-slot line and a connection between the second half loop slot line and the first sub-slot line, for turning onoff according to the external switching control signal; and
a third switching device for turning onoff in the first or second half loop slot line according to the external switching control signal, separately from the first or second switching device.
4. The radio frequency switch of claim 1, wherein the slot line pattern of the first slot line pattern portion comprises:
a 1-1 sub-slot line having an open-end circuit at an end thereof, for signal transferring with the first transmission line;
a 1-2 sub-slot line having one end connected to the connection to the other slot line pattern portions;
a common open-end circuit having both ends connected to the other ends of the 1-1 and 1-2 sub-slot lines; and
a sub-microstrip line having both ends in which a signal is transferred to and from connections between the common open-end circuit and the 1-1 and 1-2 sub-slot lines by microstrip-slot line coupling.
5. The radio frequency switch of any of claims 1 to 4, wherein the switching circuit of the second slot line pattern portion comprises:
a switching device installed on the second sub-slot line, for turning onoff according to the external switching control signal; and
switching devices installed in the vicinity of connections between the first half loop slot line and the second sub-slot line and between the second half loop slot line and the second sub-slot line, for turning onoff according to the external switching control signal.
6. The radio frequency switch of any of claims 1 to 4, wherein the switching circuit of the second slot line pattern portion comprises:
third and fourth switching devices installed in the vicinity of connections between the first half loop slot line and the first sub-slot line and between the second half loop slot line and the second sub-slot line, for turning onoff according to the external switching control signal; and
a sixth switching device for turning onoff according to the external switching control signal on the first or second half loop slot line, separately from the third or fourth switching device.
7. The radio frequency switch of any of claims 1 to 4, wherein the first, second and third transmission lines are one of microstrip lines, strip lines, coaxial lines, and coplanar waveguides (CPWs).
8. The radio frequency switch of any of claims 1 to 4, wherein the switching circuit of the second slot line pattern portion comprises:
third and fourth switching devices installed in the vicinity of connections between the first half loop slot line and the first sub-slot line and between the second half loop slot line and the second sub-slot line, for turning onoff according to the external switching control signal; and
a sixth switching device for turning onoff according to the external switching control signal on the first or second half loop slot line, separately from the third or fourth switching device.
9. The radio frequency switch of any of claims 1, 2, 3 and 5, wherein the switching circuit of the second slot line pattern portion comprises:
a switching device installed at the 2-2 sub-slot line, for turning onoff according to the external switching control signal;
a switching device installed in the vicinity of a connection between the first or second half loop slot line and the 2-1 sub-slot line, for turning onoff according to the external switching control signal; and
a capacitor installed across the gap of the first or second half loop slot line, facing the switching device installed at the first or second half loop slot line.
10. The radio frequency switch of any of claims 1 to 5, wherein the first, second and third transmission lines are one of microstrip lines, strip lines, coaxial lines, and coplanar waveguides (CPWs).