US3435760A

US3435760A - Bed and platen printing machine with heated transfer ribbon

Info

Publication number: US3435760A
Application number: US610683A
Authority: US
Inventors: Harry Harrison
Original assignee: SULMIST Ltd
Current assignee: SULMIST Ltd
Priority date: 1966-03-04
Filing date: 1967-01-20
Publication date: 1969-04-01
Anticipated expiration: 1986-04-01
Also published as: GB1133652A; DE6606302U; DE1561368A1

Description

H. HARRISON April 1, 1969 BED AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON Sheet Filed Jan. 20, 1967 I INVENTOR: HA RRY HARRISON H. HARRISON 3,435,760

BED AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON April 1, 1969 Sheet Filed Jan. 20, 1967 Q 3 Q Q R HARRY HARRY ZW April 1, 1969 H. HARRISON 3,435,760

BED AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON Filed Jan. 20', 1967 Sheet 3 of 3 INVENTOR;

HARRY HARRISON (Du/M d d n/lube,

United States Patent 3,435,760 BED; AND PLATEN PRINTING MACHINE WITH HEATED TRANSFER RIBBON Harry Harrison, Heywood, England, assignor to Sulmist Limited, Heywood, Lancashire, England, a British company Filed Jan. 20, 1967, Ser. No. 610,683 Claims priority, application Great Britain, Mar. 4, 1966,

Int. Cl. B41f 1/00, 31/16; B44b /00 US. Cl. 101-287 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to high speed cording machines which use heat transfer printing tape in the course of operation.

The technique in printing of using heat transfer printing tape is known. One type of tape used in this technique comprises a ribbon of cellophane coated with size or ink which serves for printing of the characters required. Such tape is hereinafter referred to as printing tape.

The technique may be used for printing a character such as an identification number, a price, a quality, grade indication and these may be printed on lbags, wrappers, labels or other suitable articles. In use, the articles to be printed pass the coding machine one by one and receive a suitable imprint.

In one known coding machine, a reciprocating, letterpress printing action is used but this machine requires the conversion of rotary motion into rectilinear motion.

It is the object of this invention to obviate or mitigate this disadvantage.

According to this invention there is provided a coding machine which comprises a printing head, adapted to carry a printing die and past which the printing tape is adapted to pass in use, a printing tape indexing means, solenoid means operatively connected to the printing head and the indexing means, control means operatively connected to the solenoid means and operable to energize the solenoid means and cause in turn a printing action of the head and then an indexing action of the indexing means.

Preferably, the solenoid means includes a printing solenoid to provide the printing action of the head and the movable core of which carries the printing head.

Also, the solenoid means further includes an indexing solenoid the core of which when the solenoid is energized moves the indexing mechanism such as to index the tape past the printing head.

One embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

Patented Apr. 1, 1969 "ice FIG. 1 is a side elevation of the coder;

FIG. 2 is a plan of the coder; and

FIG. 3 is a circuit diagram of the control circuit.

Referring to FIGS. 1 and 2, the machine has a metal frame of inverted L-section and comprising a vertical side plate 2 and an upper horizontal plate 4. Depending from the lower edge of plate 2 are a pair of spaced legs 5 on each of which is mounted a printing tape guide bar 6. Approximately at the mid height of the plate 2 there is a horizontal solenoid bed 8 secured to the vertical plate 2 and overlying the tape guides 6.

There is at one end of the side plate 2, level with the solenoid bed 8, a horizontal magazine spool axle and at the opposite end of the plate 2, a take-up spool axle 12, both axles projecting horizontally from the vertical side plate 2 and supporting a freely rotatable magazine spool .14 and a take-up spool 16 respectively. One or other of these spools 14, 16 may be slightly spring loaded so as to give a slight tension to the tape as it is being fed from one to the other. Heat transfer printing tape 18 on spool .14 is threaded under the guides 6 to the other spool 16 thereby covering the space or window between the guides 6.

Between the solenoid bed 8 and the upper plate 4 there is a printing solenoid 20. The solenoid bed is apertured to allow the solenoid core 22 to reciprocate vertically. The lower end of the core 22 carries a press-printing head and two tension springs 24 connect the head to the upper plate 4, which springs urge the core 22 and the printing head in a vertical, upwards direction. The head comprises a block-shaped holder 26, the lower face 28 of which is recessed to accommodate a maximum of seven side-by-side A high printing dies '30. When in position, the faces of the dies project through and below the tape guides 6.

The holder 26 is small enough to pass through the window defined by the tape guides 6 and it contains a resistance heating element, here symbolically represented by the resistor 25, to heat the printing tape prior to printing. The element temperature is controllable between 5 0 and 300 C. and there is also a thermostat control to prevent overheating of the tape 18.

On the reverse side of the vertical side plate 2. near the magazine spool axle 10 there is a horizontal shaft 32 which acts as a mounting for a wind-on or indexing solenoid 34. Connected to the solenoid casing is a bifurcated lug 35 journalled on shaft 32.

Near the take-up spool shaft 112 there is an L-shaped bracket 36 providing a further bearing for the take-up spool axle 12. Between the takeup spool 16 and the side plate 2 there is a ratchet and pawl mechanism 38.

On the take-up spool axle 12 and lying between the bracket 36 and the side plate 2, is a crank 40 which is integral with the drum or input member of a one way spring clutch 42.

The core 44 of the wind-on solenoid 34 is urged by the spring 47 to the right in FIG. 1 and has a bifurcated lug 45 on its outer end which is connected to the crank 40. As the solenoid core 44 moves to and fro in use, the end of the crank 40 describes a short arcuate movement causing the wind-on solenoid 34 to pivot slightly on the shaft 32. In the indexing direction of movement the clutch is engaged and causes indexing of shaft '12 to wind-on the tape 18, but when the solenoid 34 is de energized the core returns under spring action to the position of FIG. 1, the clutch 42 being free and the spool axle .12 being prevented from rotating by the ratchet and pawl mechanism 38.

Referring now to the control circuit indicated in FIG. 3, the printing solenoid is indicated by 46 and the wind-on or indexing solenoid by 48. The circuit comprises a transformer 50 of which the primary is connected to the mains via a switch if desired and the secondary is centre tapped, rectified and smoothed to give a -22 volt line 52, a zero volt line 54 and a +22 volt line 56. The switch 58 controls the operation of the

solenoids

46 and 48.

With the switch 58 in the position shown, capacitor 60 is being charged from lines 52 and 54 and also the transistors T2, T4 and T6 are conducting, thus the indexing solenoid is energized and at switch-on the spool 16 is indexed to draw a small length of tape past the printing head. i

If now the switch 58 is thrown to the other contact, as for example by transporting upon a conveyor 27 (FIG. 1) the articles (or article) to be printed on in positions to cause the switch to be actuated by each passing article, transistors T1, T3 and T commence conducting, the print solenoid winding 46 is energized and the printing head moves down and imprints the characters of the die onto the article label or sheet or the like under the head 28-. The winding 46 will remain energized, regardless of whether or not the switch 58 is thrown back to the position indicated in FIG. 1 or not, for a period determined by the time constant of the circuit C R- the latter being variable to vary the predetermined time. Thus, the printing head is held in position for said time to ensure efficient printing of the characters. In actual practice, the switch 58 will be moved to its other position momentarily and then back to the position of FIG. 1 so that the capacitor 60 is again being charged during printing.

In an application of applying coding to paper wrappers, the machine is clamped by clamping brackets above a conveyor along which the paper wrappers are fed. The machine is loaded with tape as indicated in FIG. 1 and the heating element switched on to heat the tape and cause a slight melting of the printing ink so that it will adhere effectively to each wrapper. The variable resistor R is adjusted appropriately to the desired rate of feed and when a wrapper comes under the tape guide rail 6, this causes the changeover switch 58 momentarily to initiate the sequence of operations given above.

In this event, the printer solenoid is energized and the wind-on solenoid is de-energized, the core 22 and printing dies 30 descend and push the stationary tape 18 into contact with the wrapper passing just beneath the tape guides 6 to effect printing on the label.

There now follows a pre-set short delay as fixed by time constant of R C in which the printing head is held in contact with the tape. After the pre-set interval which is usually less than a second, a change of state as abovementioned takes place and the wind-on solenoid 114 is energized and the print solenoid is tie-energized, being returned by spring action and the printing head is returned by the springs 24.

The core 44 of the wind-on solenoid through clutch 42, now rotates take-up spool 16 in an anticlockwise direction sutficiently to draw a fresh unprinted area of tape from the magazine spool 14 past the printing 'dies 30 and the circuit is again in the initial condition.

The apparatus is now ready to initiate again the changeover switch momentarily to cause another printing. It will be appreciated that the operation of printing is continuous, there being a complete cycle as each wrapper passes the printing head.

We have found that the above embodiment is capable of printing speeds of up to 5 operations/ second and with suitable printing tape will print on cellulose film, waxed papers, polythene, polypropylene, metal foils, laminates and other surfaces which are difficult to print with wet ink techniques.

In another embodiment the changeover switch 58 is a micro switch which is moved by the cam of an auxiliary packaging machine.

What we claim is:

1. In a high speed imprinting machine employing heat transfer printing tape for printing legends on articles, the imprinting machine being of the type having,

(a) a printing head having means for heating the head, the printing head carrying a printing die which can be pressed against the printing tape by movement of the head, and

(b) indexing means for intermittently drawing the tape past the printing head,

the improvement comprising,

a pair of spaced guide members over which the printing tape is drawn by the indexing means, the printing head being between the guide members and the guide members being disposed to permit the portion of the tape between the guide members to be contiguous to the heated printing die when the head is in its retracted position whereby the tape portion is heated prior to imprinting,

a first D.C. solenoid having its core carrying the printing head,

resilient means connected to the core for moving the head to its retracted position when the first D.C. solenoid is de-energized,

a second D.C. solenoid connected to actuate the indexing mechanism to draw the used portion of the tape beyond the printing head,

a control device for energizing the second D.C. solenoid immediately upon de-energization of the first D'.C. solenoid by sequentially applying direct current signals to the windings of the first and second solenoids, and

means for actuating the control device to cause the first D.C. solenoid to be energized for a time sufficient to cause a heat transfer imprinting to occur.

2. In a high speed imprinting machine according to claim 1,

the improvement further including a timing circuit in the control device for causing the first D.C. solenoid to remain energized for a predetermined period upon each actuation of the control device.

3. In a high speed imprinting machine employing heat transfer printing tape for printing legends on articles, the imprinting machine being of the type having,

(b) indexing means for intermittently drawing the tape past the printing head,

the improvement comprising,

means for maintaining a portion of the tape adjacent to the printing head when the head is in its retracted position to cause the tape portion to be heated prior to imprinting,

a first D.C. solenoid having its core carrying the printing head,

means connected to the core for moving the head to its retracted position when the first D.C. solenoid is de-energized,

a control device for energizing the second 110. solenoid immediately upon de-energization of the first D.C. solenoid by sequentially applying direct current signals to the windings of the first and second solenoids, and

(References on following page) 5 References Cited 3,198,168 UNITED STATES PATENTS 3,331,320 2/1934 Lawson 10 1-336 X 2,714,850 10/1934 Gould et a1. 101-27 5 2,801,583 8/1936 Roberts 101-9 2,672,092 8/1938 Ruttiman 101-336- X 12/1942 Vahle 101-336 X 8/1944 Runton 101-336 X 4/1955 Weber 101-336 10 11/ 1955 Schlessiger et a1. 10'1-336 101-27, 336

6 Weeks 101-336 X Grupe 101-27 X Young et a1 101-336 X Kistner 101-336 X Loushay 101-108 Beattie 101-336 WILLIAM B. PENN, Primary Exatrminer.

U.S. Cl. X.R.