CH656955A5 - METHOD AND DEVICE FOR CLAMPING, HOLDING AND CLAMPING A SHEET-SHAPED RECORDING CARRIER ON A DRUM. - Google Patents

Description

The invention relates to a method and a device for clamping, holding and unclamping a sheet-shaped recording medium in a recording device with a drum rotatably mounted around the longitudinal axis of a first shaft, designed as a vacuum hollow cylinder and provided on the outer peripheral surface with a suction channel system .

For holding a writing sheet in a recording device with a rotatably mounted drum according to DE-C 2 349 217, a device is known which, for clamping the writing sheet, has a plurality of clips projecting outwards through a slot and for holding the writing sheet one in a longitudinal groove of the drum and includes a ruler extending axially over the drum. For clamping, one end of the writing sheet is inserted between the brackets, each provided with an angled shoulder and a groove and mounted on an axis eccentrically to the longitudinal axis of the drum, pressed by the brackets against the bottom of the drum slot and then through the Dre-50 hung the drum under the spring-loaded ruler and after completing the rotation for the actual recording process clamped the other end of the writing sheet under the ruler. After the recording process has been completed, the writing sheet is manually removed from the drum by loosening the clips and the ruler. In the device described, the writing sheet is held on the one hand by the clamps and on the other hand by the ruler on the drum surface for the recording process. 60 The state of the art also includes recording devices of a modern design for higher recording speeds according to US-A 4101018 and DE-A 3 000 887, in each of which a sheet-shaped recording medium essentially consists of a drum shell on the outside thereof Circumferential surface generated negative pressure is largely stable and smoothly held on the drum surface.

The method according to the invention has the task of

3rd

656 9SS

With the help of one of the above-mentioned prior art and designed as a vacuum hollow cylinder drum a recording medium for the recording process without additional manual help, functionally reliable and quickly clamped and unclamped.

The method according to the invention is characterized in that the recording medium fed to the drum for the recording process is recorded and then drawn onto the rotatingly driven drum in a smooth manner and held in a stable position by the negative pressure, and that after the recording process has been completed, the recording medium is automatically lifted off the drum surface and from the drum is derived.

According to a further feature, the method according to the invention is characterized with the aid of at least one actuating member mounted on a second shaft and a plurality of gripper elements, characterized in that the actuating member, which is operatively connected to the second shaft, and the individual gripper elements are connected to the recording medium by means of the engagement of a first switching skid and for anchoring of the record carrier can be pivoted about the longitudinal axis of the second shaft by the engagement of a second switching skid.

The device according to the invention for carrying out the above-mentioned method comprises the second shaft mounted in the drum, the actuating member and the gripper elements, each pressed with a clamping part against a clamping part provided on the drum body, and is characterized in that a) the actuating member laterally on the drum body on the second shaft arranged and pivoted about the longitudinal axis of the second shaft,

b) the individual gripper element is arranged in a recess provided in the drum body and is pivotably mounted on the second shaft against the restoring force of at least one spring,

c) the gripper element for clamping the recording medium has a recess between the inside of the clamping part and a web oriented essentially transversely thereto, and d) the web of the gripper element arranged under the clamping part is designed for clamping the recording medium.

Further features of the invention will become apparent from the following description in conjunction with the drawing and the claims.

The invention is described below with reference to the drawing. It shows:

1 is a perspective view of a drum with integrated clamping and unclamping device for a sheet-shaped recording medium,

2 shows the drum shown in larger scale and in side view according to FIG. 1,

3 shows a cutout, shown in plan view, of the point Y denoted by a circle in FIG. 1 with two gripper elements of the clamping and unclamping device,

4 shows a section along the line IV-IV in FIG. 3,

5 shows a section along the line V-V in FIG. 3 with the gripper element of the clamping and unclamping device shown in a sectional view,

6 shows a section through the tensioning and tensioning device along the line VI-VI in FIG. 5, and

Fig. 7 shows the schematically shown mounting and tensioning phase of the sheet-shaped recording medium on the drum.

1 shows a schematically illustrated perspective view of a drum 100 for a recording device (not shown) of a liquid jet recorder. The drum 100 essentially comprises a drum body 10 with an integrated clamping and unclamping device 30 for a sheet-shaped recording medium 90. The hollow cylindrical drum body 10, which is closed on both sides by a drum base 14, 15, is replaced in the axial direction by one as a hollow body formed, centrally arranged in the drum body 10 through-10 penetrated and is rotatable together with the first shaft 12 about the longitudinal axis X in the direction of arrow 1 in the recording device. The first shaft 12, which is operatively connected to a suction unit 18 on one side via a line 17, has a recess 12 'in the interior 11 of the drum 15 body 10. The jacket 10 'of the drum body 10 is provided on its outer circumferential surface with a schematically illustrated channel system 5, which is connected to the interior 11 through openings, not shown. By means of the 20 suction unit 18, a negative pressure is generated on the drum body circumferential surface, by means of which the recording medium 90 mounted on the drum body 10 is held on the outer circumference of the drum body.

The drum 100 is mounted in the record carrier with two bearing blocks 16 arranged laterally on the drum body 10, which is partially broken open in FIG. 1, 25, only one bearing block 16 being shown in FIG. 1. Furthermore, one can see in FIG. 1 a weight-compensating body 13 which corresponds to the clamping and unclamping device 30 and 30 and which is arranged parallel to the first shaft 12 and is mounted in the two drum bottoms 14, 15 in a manner not shown in detail and not shown Means is attached.

The clamping and unclamping device 30, shown schematically in FIG. 1, comprises a plurality of gripper elements 35, which are distributed in the axial direction of the drum 100 and are mounted on a second shaft 31. The second shaft 40 31, which penetrates the drum body 10 and essentially the two drum bottoms 14, 15 in the axial direction, is arranged in bearing parts 40 fastened to the side of the drum bottoms, only the bearing part 40 fastened to the drum bottom 15 by means not shown being shown in FIG. 1 is. 1 also shows an actuating member 33 mounted on the second shaft 31 and an overrun body 34 arranged on the actuating member 33.

2, the drum 100 is shown in a side view, and one can see the end face of the drum base 15, the bearing part 40 fastened to the drum base 15, the second shaft 31 arranged in the bearing part 40, and the actuating member 33 mounted on the second shaft 31 with the casserole body 34 attached to it.

Furthermore, one can see a recess 15 'provided in the area of the clamping and bracing device 30 in the drum base 15, the jacket 10' of the drum body 10 which is visible in the area of the recess 15 'and a section of a shell-shaped tubular body 20. The tubular body 20 penetrates in the axial direction the drum body 10 and essentially separates the interior 11 from the clamping and bracing device 30.

So in Fig. 3 is a top view of the location Y shown in Fig. 1 by a circle, and you can see on one side partially broken and shown in section 10 'of the drum body 10, the drum base 15 and that on the front side of the drum base 15 65 fastened bearing part 40 for the second shaft 31. In the drum body 10 spaced-apart recesses 25 are provided, in which the gripper elements 35 mounted on the second shaft 31 are arranged.

656955

Furthermore, one can see a partially visible section of the tubular body 20, which is fastened to the drum body 10 with screws 22, 22 ′.

FIG. 4 shows, in section along the line IV-IV in FIG. 3, the recess 25 for the individual gripper element 35. The recess 25 is in the radial direction through walls 23, 23 'and in the axial direction through walls 24, 24 '(Fig. 6) limited. On the one hand, following the recess 25, a guide slot 26 oriented in the radial direction of the drum body 10 and delimited by a wall 26 ′ and a clamping section 27 oriented in the axial longitudinal direction of the drum body 10 are provided for the gripper element 35. As can be seen from FIGS. 1 and 4, the clamping section 27 extends in the axial direction over the entire length of the drum body 10.

Fig. 5 shows on a larger scale a section along the line VV in Fig. 3, and you can see a portion of the shell 10 ', a portion of the drum base 15, the bearing part 40 attached to the drum base 15 and arranged in the jacket 10' Recess 25. As already mentioned, the recesses 25 arranged at a distance from one another in the drum body 10 are separated from the interior 11 of the drum body 10 by the tubular body 20. A support member 21, 21 'is attached to the shell-shaped tubular body 20 on each side. The two support parts 21, 21 'are provided on one side with a shape corresponding to the inside diameter of the drum body 10. The tubular body 20 penetrating the drum body 10 in the axial direction is fastened in a sealed manner in the interior 11 of the drum body in the area of the recesses 25 by means of the screws 22, 22 '(FIG. 3) and the support parts 21, 21'. On the underside of the two bearing parts 40, a support 41 which penetrates the tubular body 20 in the axial direction is fastened, on which support bearings 32 which are arranged at a distance from one another are fastened by means not shown. The second shaft 31 is mounted on the one hand in the two bearing parts 40 fastened to the drum bottoms 14, 15 and on the other hand in the support bearings 32 arranged on the carrier 41.

5 also shows the gripper element 35 mounted on the second shaft 31, which essentially comprises a clamping part 36, a web 37 and a hub part 39 provided with a through hole 39 '. A recess 38 is provided between the web 37 and the inside 36 'of the clamping part 36 facing the web. The inside 36 'of the clamping part 36 and a first slope 37' of the web 37 facing the inside are arranged essentially parallel, inclined to one another. A second bevel 37 ″ is provided on the end face of the web 37, which is somewhat longer than the clamping part 36. The gripper element 35 is pushed with the hub part 39 onto the second shaft 31, is operatively connected to the second shaft by a feather key 45 and to the second shaft 31 can be pivoted in the direction of the arrow 2 about the longitudinal axis X ′ against the restoring force of at least one spring 44 acting on the gripper element 35 and on the carrier 41.

FIG. 6 shows a section through the drum body 10 according to the line VI-VI in FIG. 5, and one can see the gripper elements 35 mounted on the second shaft 31, which in the recesses delimited by the walls 24, 24 'of the casing 10' 25 are arranged. Furthermore, one can see the drum base 15, the tubular body 20 mounted in the recess 15 ', the bearing part 40 fastened to the drum base by means not shown, the support 41 fastened to the bearing part 40 and the support bearing 32 fastened to the carrier 41 by means not shown for the second shaft 31.

In the exemplary embodiment shown, the gripper element 35 with the clamping part 36 is supported by two springs 44, 44 ′ acting on the gripper element 35 and on the carrier 41.

pulled against the clamping section 27 of the drum body 10. To fasten the springs 44, 44 ', a screw bolt 46 held by schematically illustrated securing elements 47 is provided on the web 37 of the gripper element 35 and a screw bolt 42, 42' held on the carrier 41 by schematically illustrated securing elements 43.

The operation of the clamping and bracing device 30 described is described below:

7 shows schematically and in several different positions “A” to “E” the clamping and unclamping cycle of the sheet-shaped recording medium 90 on the drum 100 rotated by means not shown about the longitudinal axis X of the first shaft 12 in the direction of the arrow 1, wherein the actuator 33 and partially the gripper element 35 in the effective clamping phase «B» and in the effective clamping phase «D» are shown by solid lines and in the effective basic positions «A», «C» and «E» by dash-dotted lines.

Starting from the basic position “A”, when the drum 100 rotates in the direction of the arrow 1 for the clamping of the recording medium 90, the actuating member 33 is brought into engagement with the ramp body 34 with a first switching skid 50. When contacting the ramp body ball part 34 'with the ramp surface 50', the actuating member 33 mounted on the second shaft 31 and thus operatively connected as well as the gripper element 35 operatively connected to the second shaft 31 correspondingly about the axis X 'of the second shaft 31 from the basic position in Arrow direction 2 pivoted and deflected. As soon as the ramp body ball part 34 ′ contacts the sliding surface 50 ″ of the switching skid 50, the maximum deflection of the two parts 33, 35 and, at the same time, a rest position “B” of the drum 100 for inserting and tensioning the recording medium is reached.

In the rest position “B”, for example, the recording medium 90 is pulled from a roller (not shown) arranged in the recording device and inserted through correspondingly assigned guide plates 51, 52 into the recess 38 provided between the web 37 and the clamping part 36 of the gripper element 35 in the direction of the arrow 3 . Subsequently, the switching skid 50 is brought out of engagement of the outlet body 34 in a manner not shown in detail, so that as a result the ramp body ball part 34 'is disengaged from the sliding surface 50 "and at the same time the two parts 33, 35 are released by the restoring force of the springs 44, 44'. be pivoted into the basic position in which the recording medium 90 is clamped between the clamping surface 36 'of the clamping part 36 and the clamping section 27 provided on the drum body 10.

For the recording process, the drum 100 is rotated in the direction of arrow 1, the recording medium 90 being held in the clamping phase by the gripper elements 35 and in the recording phase additionally by the negative pressure generated on the drum body circumferential surface by means of a negative pressure which is stable and smoothly against the drum body 10. A further pressure roller 80 tangent to the drum 100 and driven thereby in the direction of the arrow 4 brings about a faultless transport of the recording medium 90 in particular in the tensioning phase - the partially lifted recording medium 90 is no longer adequately captured and transported by the negative pressure.

After the end of the recording, the braked rotary movement for unclamping the recording medium 90 from the drum 100 in a manner not shown

4th

s

10th

15

20th

25th

30th

35

40

45

50

55

60

65

a second switching skid 55 is fed and brought into engagement with the actuating member 33 rotated in the basic position “C” with the drum 100 in the direction of arrow 1. When contact is made between the ball body part 34 'and the ball surface 55', the actuating member 33 and the gripper element 35 are deflected accordingly and the tensioning phase “D” is initiated. As soon as the ramp body ball part 34 'contacts the sliding surface 5 "of the skid 55, the maximum deflection of the two parts 33, 35 and thus the transfer phase of the recording medium is reached. In this phase, the front part of the recording medium 90 is due to the rotary movement of the parts 100, 33 and 35 have already been pulled out of the recess 38 of the gripper element 35, raised by the web 37 and inserted through the second bevel 37 "of the web 37 in the direction of the arrow 3 'into an intermediate space 58 of two guide plates 56, 57 arranged at a distance from one another. The comb-like guide plates 56, 57, not shown, are provided with correspondingly designed recesses, not shown, for the pivoting movement of the gripper elements 35. After the end phase «D»

5 656955

with a uniform rotary movement of the drum 100, the ramp body ball part 34 'out of engagement of the sliding surface 55 ", as a result of which the two parts 33, 35 are pivoted into the basic position" E "by the restoring force of the springs 44, 44'.

For the rotational movement of the drum 100 in the direction of arrow 1 required for the recording process, the two switching runners 50, 55 are disengaged by means not shown and in a manner not shown, out of engagement of the actuating part 33 rotating together with the drum 100 and for the clamping and unclamping process. 7 position "B" and position "D", brought back into engagement of the actuating part 33. The sliding surface 55 ″ of the first switching skid 50 and the sliding surface 50 ″ of the second switching skid 55 15 are preferably arranged in a circular arc, concentric to the axis X of the first shaft 12.

The positions of the parts 33, 35 with respect to the drum body 10 are essentially the same in the basic positions “A”, “C” and “E” 20, disregarding the respective sheet thickness of the recording medium.

6

3 sheets of drawings

Claims (10)

656955 PATENT CLAIMS 1. A method for clamping, holding and unclamping a sheet-shaped recording medium (90) in a recording device with a hollow cylinder which is rotatably mounted around the longitudinal axis of a first shaft (12) and is designed as a vacuum hollow cylinder and has an intake channel system (5) on the outer circumferential surface. provided drum (100), characterized in that the recording medium (90) supplied for the recording process of the drum (100) is grasped and then drawn onto the rotatingly driven drum (100) in a smooth manner and is held in a stable position by the negative pressure and that after the recording process has been completed, the recording medium (90 ) is automatically lifted from the drum surface and is derived from the drum (100). 2. The method according to claim 1, with the aid of at least one actuating member (33) mounted on a second shaft (31) and a plurality of gripper elements (35), characterized in that for clamping the recording medium (90) that with the second shaft (31) operatively connected actuator (33) and the individual gripper elements (35) through the engagement of a first switching skid (50) and for bracing the record carrier (90) through the engagement of a second switching skid (55) about the longitudinal axis (X ') of the second shaft (31 ) can be pivoted. 3. The method according to claim 1 and 2, characterized in that the clamping of the record carrier (90) in a rest position and the bracing takes place when the rotary movement of the drum (100) is braked. 4. Device for performing the method according to one of claims 1 to 3, comprising the second shaft (31) mounted in the drum (100), the actuating member (33) and each with a clamping part (36) against an am-drum body ( 10) provided clamping section (27) pressed gripper elements (35), characterized in that a) the actuating member (33) is arranged laterally on the drum body (10) on the second shaft (31) and can be pivoted about the longitudinal axis (X ') of the second shaft is stored, b) the individual gripper element (35) is arranged in a recess (25) provided in the drum body (10) and is pivotably mounted on the second shaft (31) against the restoring force of at least one spring (44, 44 '), c) the gripper element (35) for clamping the recording medium (90) has a recess (38) between the inside (36 ') of the clamping part (36) and a web (37) oriented essentially transversely thereto, and d) that under the clamping part (36) arranged web (37) of the gripper element (35) is designed to unclamp the recording medium (90). 5. Device for carrying out the method according to claim 2, characterized in that the first switching skid (50) has an arcuate sliding surface (50 ") and the second switching skid (55) has an arcuate sliding surface (55") and that both sliding surfaces ( 50 ", 55") are arranged concentrically to the axis (X) of the first shaft (12) of the drum (100). 6. Device according to claim 4, characterized in that an overrun body (34) with a spherical body part (34 ') is arranged at one end of the actuating part (33). 7. Device according to claim 4, characterized in that the clamping and bracing device (30) formed essentially from the second shaft (31), the gripper elements (35) and the actuating member (33) is formed as a structural unit in the drum body (10 ) is arranged and stored. 8. Device according to claim 4 and 7, characterized in that the clamping and unclamping device (30) through a half-shell-shaped tubular body (20) penetrating the drum body (10) in the axial direction with respect to the interior (11) of the drum body ( 10) is sealingly separated. 9. Device according to claim 4, characterized in that the recess (38) provided in the gripper element (35) through the inside (36 ') of the clamping part (36) and through a first bevel (37') arranged at a distance from it. of the web (37) and that the first io slope (37 ') and the inside (36') are arranged essentially parallel, inclined to one another. 10. Device according to claim 4, characterized in that the web (37) with respect to the hub part (39) of the gripper element (35) somewhat longer than the clamping part (36) 15 is formed and is provided with a second bevel (37 ") on its end face for lifting off the record carrier (90). 11. The device according to claim 4, characterized in that the clamping section (27) in the installed state 20 of the gripper element (35) corresponding to the slope of the inside (36 ') of the clamping part (36), extends in the axial direction over the entire length of the drum body (10) and for guiding the gripper element (35) with spaced apart Slots (26) for 25 the web (37) is provided.