1. Field of the Invention
The present invention relates to a web feed method and feed apparatus used in a printing machine.
2. Description of Related Art
A conventional web feed apparatus will be described with reference to
FIGS. 13(a) and (b) are schematic drawings showing a continuous web feed apparatus 1a in which the web 3 is attached at zero speed. The web 3 fed from the web roll 2a passes through an upper guide roll group 51 and a lower guide roll group 52 alternately, and is fed to the next apparatus over a long-distance route.
In the status shown in FIG. 13(a), when the amount of the web remaining on the web roll 2a becomes small and the roll 2a is to be switched over to a new web roll 2b, the web 3 stored in a web storage apparatus 50 is discharged by reducing the gap H between the upper guide rolls 51 and the lower guide rolls 52 as shown in FIG. 13(b). Then, web roll 2a is stopped and an automatic web connecting apparatus 30 is operated; then the running web 3 is pressed against the tip of a new web roll 2b by a pressing apparatus 37. When the web 3 on the side of the web roll 2a is cut off by a saw blade 38, the web 3 can be fed from the new web roll 2b. After that, the web storage apparatus 50 is returned to the original position (as shown in FIG. 13(a)) with the speed of web roll 2b being increased, and the web 3 is thus continuously fed. The amount of stored web is then brought to a maximum to become ready for the next attachment of a subsequent roll web.
Further,
In the state shown in FIG. 14(c), a remaining web core 6 is removed by an unloading apparatus (not illustrated). As shown in FIG. 14(d), a new web roll 2a′ ready for attachment at the tip of the web is mounted by a loading apparatus (not illustrated), and the arm 56 supporting the web rolls 2 is turned in the direction indicated by an arrow in the drawing so that the condition shown in FIG. 14(b) is realized. This procedure is repeated to feed the web 3 continuously. When a high-quality web is to be fed, a problem may occur if front and back sides are reversed by the splicing of web 3. This arrangement is preferable in the sense that such a problem can be avoided. In
A continuous web feed apparatus Ic in
FIGS. 18(a) and (b) show a continuous web feed apparatus Id wherein the arm 59 supporting the web roll 2 feeds the web 3 continuously by rocking, not by rotation. This continuous web feed apparatus Id comprises (1) arms 59a and 59b supporting two web rolls 2a and 2b, respectively, (2) an automatic web splicing apparatus 30a for splicing the web 3a on the left to the new web roll 2b, and (3) an automatic web splicing apparatus 30b for splicing the web 3b on the right to the new web roll 2b. The arms 59a and 59b are supported by support shafts 60a and 60b, and are designed to rock about the support shafts 60a and 60b.
FIG. 18(a) shows how web 3 is unwound from the web roll 2a. When the amount of the web remaining on the web roll 2a becomes small, the surface speed of new web roll 2b is increased to reach the same speed as that of the running web 3a. The automatic web splicing apparatus 30a is pushed out in the arrow-marked direction, and the web 3a is pressed against the new web roll 2b by the pressing apparatus 37a. The web 3a is brought in contact with the tip of the web on the web roll 2b, and web 3b is unwound from the web roll 2b. At the same time, the web 3a having been unwound from the web roll 2a is cut off by the saw blade 38a. Then the web core remaining on the web roll 2a is removed by the unloading apparatus (not illustrated), and a new web roll 2a′ is installed by the loading apparatus (not illustrated) as shown in FIG. 18(b). Further, when the amount of the web remaining on the web roll 2b becomes small, the surface speed of new web roll 2a′ is increased to reach the same speed as that of the running web 3b. The automatic web splicing apparatus 30b is moved in the arrow-marked direction, and the web 3b is pressed against the new web roll 2a′. Then the web is spliced and switched in the same procedure as above.
In the aforementioned prior art web feed apparatus and feed method, however, a continuous web feed apparatus 1a shown in
Further, the continuous web feed apparatus 1b of rotary arm type shown in
FIG. 16(a) shows a slip ring 53 as an example of the apparatus for transmitting electricity from the stationary side to the rotary side. This slip ring 53 is provided on the rotating support shaft 57 according to each type of electricity (having different signal, voltage, etc.) to be connected. It slides in contact with carbon, etc., whereby electricity is transmitted from the stationary side. However, it has a complicated structure and involves complicated procedures in the replacement of consumed carbon or in the maintenance work to keep the surface conductivity of the slip ring 53 in good conditions. This requires a great deal of time and costs. Further, it is difficult to maintain high performances of a high-precision control system 4 when the slip ring 53 is used, because of many problems; namely, insulation work is essential for a large capacity product, for example. Further, the installation space must be expanded.
FIG. 16(b) shows a rotary joint 54 as an example of the apparatus which feeds fluid from the stationary side to the rotating side. In this rotary joint 54, the pipe on the stationary side and individual flow paths provided on the rotating support shaft 57 are connected with each other. In this case, a clearance for rotation is required between the rotary portion and stationary portion. Presence of a clearance is accompanied by possible fluid leakage. So sealing material 55 for avoiding fluid leakage is necessary. However, sealing material 55 is a consumable component which requires maintenance work. At the same time, this increases rotational loads. Moreover, many flow paths requiring difficult machining work is required inside the support shaft 57; and this will increase costs. Further, similarly to the case of the aforementioned slip ring 53, the overall installation space must be increased since rotary joint 54 is provided.
In the continuous web feed apparatus Ic shown in
In the continuous web feed apparatus Id shown in
The present invention has been made to solve the aforementioned problems, and the object thereof is to provide a web feed method and feed apparatus characterized by a reduced installation space, a simple structure and easy maintenance control, with the front and back of the continuously fed web kept unchanged.
To solve the problems of the aforementioned prior art, the present invention uses an apparatus for holding two web rolls and unwinding a web on a continuous basis by means of an automatic web splicing apparatus. Arms supporting the web rolls are rocked when the unwinding of the web is switched between the web rolls. When this web is switched from a first web roll (roll A) to a second web roll (roll B), the remaining core of the first web roll (roll A) is removed subsequent to switching. Then the installation position for the first web roll (roll A) is shifted onto the opposite side with respect to the web being unwound from the second web roll (roll B), then a new web roll is mounted in position to take the place of the first web roll. By contrast, when the web is switched from the second web roll (roll B) to the first web roll (roll A), the remaining core of the second web roll (roll B) is removed subsequent to switching, and the installation position for the new web roll is arranged in such a way that the new web roll is mounted to take place of the second web roll on the same side with respect to the web being unwound from the first web roll (roll A). The web is fed continuously in this manner.
As described above, the web feed method according to the present invention uses an automatic web splicing apparatus. Arms supporting the web rolls are rocked when unwinding of the web is switched from one roll to another. When the source of this web is switched from a first web roll (roll A) to a second web roll (roll B), the remaining core of the first web roll (roll A) is removed subsequent to the switching. Then the installation position for the first web roll (roll A) is shifted onto the opposite side with respect to the web being unwound from the second web roll (roll B), then a new web roll is mounted in position to take the place of the first web roll. In contrast, when the source of the web is switched from the second web roll (roll B) to the first web roll (roll A), the remaining core of the second web roll (roll B) is removed subsequent to the switching, and the installation position for the new web roll is arranged in such a way that the new web roll is mounted to take the place of the second web roll on the same side with respect to the web being unwound from the first web roll (roll A). The web is fed continuously in this manner. So the present method is suited for high-quality web feeding.
The present invention comprises:
As described above, the web feed apparatus according to the present invention comprises:
FIG. 3(a) is a plan view representing a continuous web feed apparatus according to the first embodiment of the present invention;
FIG. 3(b) is a detailed view of portion P in FIG. 3(a);
FIGS. 6(a) to 6(h) are schematic drawings representing the automatic web splicing operation of a continuous web feed apparatus according to the first embodiment of the present invention;
FIGS. 8(a) to 8(h) are schematic drawings representing the automatic web splicing operation of a continuous web feed apparatus according to the second embodiment of the present invention;
FIGS. 9(a) to FIG. 9(i) are schematic drawings representing the automatic web splicing operation of a continuous web feed apparatus according to the third embodiment of the present invention;
FIG. 10(a) is a front view representing how a full-width web roll is installed on a continuous web feed apparatus according to the fourth embodiment of the present invention;
FIG. 10(b) is an enlarged view representing portion Q in FIG. 10(a);
FIG. 13(a) is a schematic explanatory diagram representing a prior art continuous web feed apparatus for splicing a web at zero speed;
FIG. 13(b) is a schematic explanatory diagram representing the status at the time of switching to a new web roll in FIG. 13(a);
FIGS. 14(a) to 14(d) show a web splicing procedure;
FIG. 16(a) shows the case where electric power is supplied;
FIG. 16(b) shows the case where fluid such as compressed air or water is fed;
FIG. 17(a) is a plan view thereof;
FIG. 17(b) is a front view thereof;
FIG. 18(a) shows the state of a web being unwound from a web roll; and
FIG. 18(b) shows how the remaining web core is removed and a new web roll is installed.
The details of the present invention with reference to the illustrated embodiment will be described in the following.
Unless otherwise specified, the dimensions, material, configurations and relative positions of the components described in the continuous web feed apparatus according to the first embodiment of the present invention are not restricted to specifics that will be mentioned below. The following discussions are given only as examples for the sake of illustration. The same portions as the aforementioned conventional examples will be assigned with the same reference numerals, and duplicated descriptions will be omitted.
In
Arms 12 supporting two roll support apparatuses 20 are provided on opposite sides across the width of the web roll 2. These arms 12 have a block shape, and are shaped approximately in the shape of letter S, when viewed from the side, with concave portions 17 provided on the upper and lower surfaces at opposite positions. These arms are rockably (or rotatably) configured. Thus, the arms 12 on the opposite sides of the web roll 2 are fixed in position by a beam 13 and are connected with each other. Support shafts 14 are provided outside the rocking centers in the width direction. Accordingly, the roll support frame 11 is composed of arms 12, beams 13 and support shafts 14. The support shafts 14 of the roll 15, support frame 11 are supported by bearings (not illustrated) on frames 4 installed on opposite sides in the axial direction.
On the shaft end of one of the aforementioned support shafts 14 on both sides, a rocking drive apparatus 16 for rocking the support shaft 14 is mounted on the frame 4, and a rocking position detector 8 for detecting the rocking position of the roll support frame 11 is installed on the end of this support shaft 14 so as to be engaged therewith. Further, a control apparatus 7 for controlling various operations is provided at the position associated with the continuous web feed apparatus 1 and carries out controlling functions based on signals from the rotating position detector 8 and signals responsive to the conditions of the continuous web feed apparatus 1.
Multiple guide rollers 15 for guiding the web 3 unwound from the web roll 2 are provided around the beam 13.
Relationship between the arm 12 of the aforementioned roll support frame 11 and the roll support apparatus 20 is configured in such a way that the roll support apparatus 20 can be moved in the axial direction of the web roll 2 by the guide 23 (guide 23A on the arm 12 and guide 23S on the roll support apparatus 20 side are engaged for guiding) provided in the axial direction of the web roll 2, on the support portion of the web rolls 2 of the arms 12 on both sides across the width.
Chucks 22a and 22b for mounting the core of the web roll are rotatably supported on the roll support apparatus 20. Moreover, the roll support apparatus 20 is configured in such a way that a brake for applying an appropriate tension can be applied to it at the time of unwinding the web 3, and it can be driven by a roll drive control motor 26 for accelerating the web roll 2 at the time of splicing. The aforementioned roll support apparatus comprises a support block 21 for supporting them and a traveling mechanism 24 for moving the aforementioned support block 21 along the guide 23. This traveling mechanism 24 comprises a rack 24S on the support block, and a pinion 24A, traveling motor 25 and position detector 27 on the arm 12 side. The aforementioned support block 21 is configured in such a way as to synchronize the support blocks 21a and 21b on both sides with each other and to shift the position thereof in the axial direction or separately.
The continuous web feed apparatus 1 according to the first embodiment is arranged in such a way that a new web roll 2b mounted at the specific rocking position (FIG. 6(a) or 6(e)) of the roll rocking apparatus 10 including the roll support apparatus 20 supporting the web roll 2 and the roll support frame 11 supporting them can be spliced with running web 3 by the automatic web splicing apparatus 30, and can feed the web 3 continuously.
This automatic web splicing apparatus 30 makes an approach so as to splice the web 3 to the new web roll 2b at the aforementioned specific position, and performs its operation at the splicing position indicated by a solid line in this drawing. When the roll rocking apparatus 10 holding the web roll 2 performs the rocking operation, it is arranged to wait at the waiting position out of the relevant range as indicated by a dotted line in the drawing. Further, a guide 31 and a traveling apparatus 32 are provided inside the frame 4 so that the automatic web splicing apparatus 30 can be moved to the waiting position and the web splicing position by the aforementioned traveling apparatus 32.
As described above, to ensure that the roll rocking apparatus 10 allows the web 3 to be spliced by the automatic web splicing apparatus 30 at a specific position, the aforementioned concave portions 17 are provided on the upper and lower surfaces of the arm 12. They are intended to make new web rolls 2b and 2a′ approachable even if these web rolls 2b and 2a′ have a small diameter.
In the traveling apparatus 32 of the automatic web splicing apparatus 30, a guide 31F mounted on the frame 4 side and a guide 31P mounted on the side of the automatic web splicing apparatus 30 are engaged with each other, and pulleys 35a and 35d are installed at predetermined intervals so that a toothed endless belt 34 will run along the guide 31. The pulley 35d is installed on the shaft end of the traveling motor 33 which drives the toothed endless belt 34. Moreover, part of toothed endless belt 34 is fixed to the automatic web splicing apparatus 30 by means of a fixture 36, and the automatic web splicing apparatus 30 can be moved along the guide 31 by this endless belt 34.
To illustrate a variation of the above-mentioned first embodiment,
The automatic web splicing apparatus 30 of the first embodiment has been described to travel along the guide 31. However, this does not depend on a particular traveling mechanism; for example, an arrangement can be made so that it is moved to the splice position and the waiting position by the rocking arm.
Referring now to
The roll rocking apparatus 10 wherein two web rolls 2a and 2b are held above the roll support frame 11 by means of the roll support apparatus 20 is rocked about the support shaft 14 by the rocking drive apparatus 16. In response to various states based on the signals from the rotating position detector 8 engaged with the end of the support shaft 14, a control apparatus 7 controls the splicing of web 3, collection of the remaining core 6, mounting of the new web roll 2 and rocking of the roll rocking apparatus 10.
FIG. 6(a) shows the state of web connections for switching the web 3. This state shown in FIG. 6(a) is assumed as an origin (0 degree) of the rocking position angle of the roll rocking apparatus 10, and various states and rocking angles are represented in the subsequent figures.
As shown in FIG. 6(a), when the web roll 2a unwinding the web 3 has been reduced in diameter to come in contact with the surface of the web roll 2b, the automatic web splicing apparatus 30 located at the wait position is moved along the guide 31 mounted on the frame 4 by the traveling apparatus 32, and waits at the splice position. Then the speed of the new web roll 2b is increased by a roll drive control motor 26 through a core chuck 22. When the same surface speed has been reached between the running web 3 and web roll 2b, the pressing apparatus 37 of the splicing apparatus 30 is pushed out at timed intervals so that the running web 3 is pressed against the new web roll 2b. Then the running web 3 is brought into contact with a pasted portion prepared on the tip of the web on the surface of the new web roll 2b, and the web 3 unwound from the web roll 2a is cut off by the saw blade 38, and the web 3 is fed from the new web roll 2b.
In this case, even when the new web roll 2b has a small diameter, approach is permitted due to the presence of the arm concave 17 of arm 12 supporting the web roll 2 when the automatic web splicing apparatus 30 is located at the splice position. This makes it possible to handle a small-diameter web roll 2b wherein reduction in roll diameter often occurs upon termination of printing during use. The web 3 is guided by guide rollers 15 mounted on the automatic web splicing apparatus 30 and guide rollers 15 mounted around the beam 13 of roll support frame 11. It is further supplied while being led to the guide roller 15 to be supplied. Upon splicing of the web 3, the automatic web splicing apparatus 30 retracts from the splice position to the wait position where it waits for the next operation.
In order to reach the state shown in FIG. 6(b), the roll rocking apparatus 10 is rocked by +40 degrees (40 degrees in the clockwise direction) by the rocking drive apparatus 16. In this state, chucks 22a and 22b on the remaining core 6 side are retracted (extended to both sides) to remove the remaining core 6, and the remaining core 6 is discharged by a core collecting apparatus (not illustrated) and the like.
In order to reach the state of FIG. 6(d) while passing through the state shown in FIG. 6(c), the roll rocking apparatus 10 is rocked by −360 degrees (360 degrees in the counterclockwise direction) to be located at the −320-degree position. In this state, a loading apparatus (not illustrated) is used to carry a new web roll 2a′ into the portion where the remaining core 6 has been removed. The traveling motor 25 is driven to move the roll support apparatus 20 in the axial direction, and the web roll 2a′ is held by chucks 22a and 22b. Namely, the web roll 2a′ is mounted in the state shown in FIG. 6(d) after the above-mentioned chuck 22 has passed the web 3 unwound from the web roll 2b subsequent to removal of the web roll 2a (the remaining core 6). (Before the state of FIG. 6(c) is reached from the state of FIG. 6(b), the empty chuck is rocked beyond the running web 3.)
The web end of the new web roll 2a′ is mounted after preparations for splicing such as pasting have been completed.
This is followed by the step of turning the roll rocking apparatus 10 by +140 degrees (140 degrees in the clockwise direction) to reach the position of −180 degrees shown in FIG. 6(e). If there is no more web remaining on the web roll 2b at this position, the web 3 unwound from the web roll 2b is spliced to the new web roll 2a′ by the automatic web splicing apparatus 30 and a switching operation is performed, similarly to the case of FIG. 6(a). After that, the roll rocking apparatus 10 is turned +40 degrees (40 degrees in the clockwise direction) to reach the position of −140 degrees (FIG. 6(f)). Then the remaining web roll 2b (the remaining core 6) is removed.
Then the new web roll 2b′ is mounted at the same position. As shown in FIG. 6(g), the roll rocking apparatus 10 is turned +140 degrees (140 degrees in the clockwise direction) to get the 0-degree position (FIG. 6(h)), namely, the same phase as that of FIG. 6(a), and the web roll is switched from 2a′ to 2b′ by the automatic web splicing apparatus 30. The above procedure is repeated to feed the web 3 on a continuous basis.
What is noteworthy in this respect is as follows: In the step of switching the web roll 2, when the new web roll 2a′ on the side of web roll 2a is installed subsequent to switching of the web roll 2a over to 2b, the arm 12 is rocked subsequent to removal of the remaining core of the web roll 2a so that the chuck 22 of the relevant portion passes the running web 3. Then the new web roll 2a′ is mounted in position (from FIG. 6(b) to FIG. 6(d)). In the step of switching from the web roll 2b to the new web roll 2a′, however, the next web roll 2b′ is mounted on the side where the remaining core 6 of the web roll 2b has been removed (FIG. 6(f) to FIG. 6(g)).
The above explains the major reason why the surfaces (front and back) of the web 3 being fed on a continuous basis can be kept unchanged at all times, despite the rocking type configuration.
The continuous web feed apparatus 1 according to the first embodiment of the present invention is configured as described above, and hence the following various effects can be realized by the operation of this apparatus:
(1) The web 3 is fed on a continuous basis by rocking (not rotating) of the web roll rocking apparatus 10. This eliminates the need of mounting a slip ring, rotary joint or the like on the support shaft 14 of the roll rocking apparatus 10, thereby reducing the dimensions across the width. Further, electric components of weak current or large current can be reduced in the web roll rocking apparatus 10, with the result that high-performance can be ensured. There are additional advantages of ensuring easy maintenance and reduced maintenance costs. Further, there is no leakage loss even if compressed air or the like is used, and no power loss due to drive resistance attributable to leakage preventive sealing material.
(2) The front and back of the web 3 can be kept unchanged at all times, so this apparatus can be used as a high-quality web feed apparatus.
(3) Support shafts 14 as a rocking center of roll rocking apparatus 10 are provided on both the outer sides of arms 12 on both sides across the width, and there is no central portion across the width. When the web roll 2 is installed, the rocking diameter K is as small as 2D+C, with the result that the installation space is reduced.
(4) The arm 12 of the roll rocking apparatus 10 comprises arm concaves 17 provided in response to the positions where automatic web splicing apparatus 30 operates, and this reduces the distance of approach to new web rolls 2a′ and 2b′ at the splice position. The apparatus can be applied to new web rolls 2a′ and 2b′ having a smaller diameter web roll, thereby increasing the range of use.
The automatic web splicing apparatus 30 of
The main differences of the continuous web feed apparatus according to the second embodiment shown in
Referring now to
In FIG. 8(a), supply of the web 3 is switched from the web roll 2 on the installation side X to the web roll 2b on the side Y, and the remaining core 6 is removed in FIG. 8(b). Rocking operation is performed until the state of FIG. 8(d) is reached through FIG. 8(c); then new web roll 2a′ is mounted in position. In this state, the guide roller ISA located at a specific position with respect to arm 12 is positioned at the illustrated place, so the web 3 is arranged not to contact the web roll 2b. The position of the arm 12 in this state on the X-side is similar to what has been described with reference to the first embodiment; the new web roll 2a′ is mounted at the position where the running web 3 has rocked and passed subsequent to removal of the remaining core 6.
After that, the running web 3 is again spliced to a new web roll 2a′ in FIG. 8(e), and the web is continued to be fed from the web roll 2a′. After the remaining core 6 has been removed on the side Y in FIG. 8(f), a new web roll 2b′ is mounted at the approximate position shown in FIG. 8(g). If there is only a small amount of web remaining on the web roll 2a′, web 3 is switched from web roll 2a′ to 2b′ in FIG. 8(b). These steps are taken to ensure continuous feed of the web 3.
A continuous web feed apparatus according to the second embodiment of the present invention performs the operations mentioned above. Unlike the first embodiment, there is no beam 13 which would connect the webs 12 on opposite sides across the width. This arrangement gives the operator an easy access to the web feed apparatus 1, and hence an advantage of facilitating routine work, maintenance and inspection.
The differences of the continuous web feed apparatus of the third embodiment given in
Referring now to
In FIG. 9(e), the running web 3 is again spliced to the new web roll 2a′, and the web is continued to be fed. After the remaining core 6 on the side L has been removed in FIG. 9(f), the arm 12L is in advance rocked in the clockwise direction and is retracted in FIG. 9(g). Then the arm 12U is rocked in the counterclockwise direction to reach the illustrated position to prepare for the next step. In FIG. 9(h), the arm 12L is rocked in the counterclockwise direction, and the new web roll 2b′ is mounted on the side L at the illustrated position. In this case, installation of new web roll 2b′ subsequent to the removal of the remaining core 6 (web roll 2b) is carried out on the same side for the web 3. FIG. 19(l) shows the case where there is a decrease in the amount of the remaining web on the web roll 2a′ so that the web is switched over to the web roll 2b′, similarly to the case of FIG. 9(a). These steps are taken to sure that web 3 is fed continuously.
The continuous web feed apparatus according to the third embodiment of the present invention operates as follows: Unlike the first embodiment, two web rolls 2 are supported by arms 12U and 12L, respectively. Since arms 12U and 12L do not require rocking angles ranging up to 360 degrees, the height can be made smaller than the aforementioned first or second embodiment. This provides an advantage of saving space.
Differences of the continuous web feed apparatus according to the fourth embodiment shown in
FIGS. 10(a) and (b) show the state of full-width web roll 2 mounted in position.
In the continuous web feed apparatus of the fourth embodiment, the beam 13 is fixed onto the arm 12 of the roll support frame 11, and the guide roller 15 is supported by the arm 12 of the roll support frame 11 so as to conform to full-width web 3. The automatic web splicing apparatus 30 is also configured to conform to the full-width web 3, and performs operation guided by the guide 31 installed on the frame 4, as in the case of the first embodiment. A rack 28a constituting an arm traveling mechanism 28 is mounted on the beam 13, and a pinion 28b constituting the arm traveling mechanism 28 is installed on the traveling arm 19. The arm traveling mechanism 28 is moved by the traveling motor. Moreover, an arm position detector (not illustrated) is also mounted on the arm traveling mechanism 28 to provide position control.
The continuous web feed apparatus according to the fourth embodiment of the present invention is configured as stated above. Since webs 3 of various widths can be mounted at desired positions, this apparatus can also be used in cases where the width of the web 3 or the running position of the web 3 varies over a substantial range. Thus, this apparatus is characterized by excellent versatility, in addition to the advantages of the aforementioned first embodiment.
The embodiments of the present invention have been described above. However, the present invention is not restricted to the aforementioned embodiments. Various variations and modifications are possible based on the technological concept of the present invention.
Number | Date | Country | Kind |
---|---|---|---|
2001/178026 | Jun 2001 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
1699928 | Stone | Jan 1929 | A |
1815179 | Ball et al. | Jul 1931 | A |
2621865 | Wieking | Dec 1952 | A |
2638281 | Tollison | May 1953 | A |
3460775 | Ford et al. | Aug 1969 | A |
3467334 | Chestnut et al. | Sep 1969 | A |
4010061 | Tokuno | Mar 1977 | A |
4543152 | Nozaka | Sep 1985 | A |
4948061 | Krimsky et al. | Aug 1990 | A |
5152472 | Spang et al. | Oct 1992 | A |
Number | Date | Country |
---|---|---|
580 529 | Oct 1976 | CH |
02152850 | Jun 1990 | JP |
06048620 | Feb 1994 | JP |
Number | Date | Country | |
---|---|---|---|
20020190153 A1 | Dec 2002 | US |