GB1598710A

GB1598710A - Label-printing machines

Info

Publication number: GB1598710A
Application number: GB55478A
Authority: GB
Original assignee: Sato Kenkyusho KK
Current assignee: Sato Kenkyusho KK
Priority date: 1977-01-08
Filing date: 1978-01-06
Publication date: 1981-09-23
Also published as: FR2376750A1; DE2800440A1; JPS5397000U; BE862710A; JPS5714170Y2; NL7800084A; IT1089781B

Description

(54) IMPROVEMENTS IN AND RELATING TO LABEL-PRINTING MACHINES (71) We, KABUSHIKI KAISHA SATO KEN KYUSHO, a Japanese Company of 21-23, 3-chome, Kamikitazawa, Setagaya-ku, Tokyo Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a label printing and dispensing machine, especially of the hand-held type, (hereinafter referred to as a "label-printing machine"). More especially, the invention relates to a constant printing pressure mechanism in such a machine which is effective in the printing of labels in avoiding or tending to reduce any uneveness that may occur in the depths of printed figures.

In a conventional label-printing machine, a printing head is generally attached to the free ends of printing levers that are integrally formed with a hand lever. When the hand lever is squeezed, the printing head is lowered together with the printing levers and a label placed below the printing head is printed.

In the label-printing machine of the abovementioned type, however, the intensity of the printing force that is applied to the label is directly varied by the force with which the hand lever is squeezed, so that the depths or darknesses of printed figures are liable to vay with changes in the intensity of squeezing of the hand lever. In order to eliminate this disadvantage, constant printing pressure mechanisms have been developed in recent years.

In one type of constant printing pressure mechanism, a hand lever and printing levers are separately formed and a compression spring is interposed between the levers.

Further, an inking device is rotatably mounted in the front portion of the label printing machine with exerting the force of a return spring so as to bring the inking device into contact with the type faces of a printing head. In this mechanism, when the hand lever is squeezed, the printing head is depressed and at the same time the inking device is moved aside by the force of the compression only when the downward force of the printing levers that are pressed by the compression spring exceeds the control limit of the return spring, thereby performing the label printing.

Accordingly, the printing stroke is effected only by the compression spring and the label printing with a constant pressure can be attained regardless of the intensity of squeezing of the hand lever, and printed figures of an even darkness can be obtained.

The foregoing constant printing pressure mechanism only uses the spring in the printing levers. As a result, the force of the spring is liable to become weaker through repeated use. This weakens the force of the printing strokes. As a result, the conventional constant printing pressure mechanism does not print labels with constant depth of printed figures.

In another label printing machine having a constant printing pressure mechanism, a hand lever and a printing lever are formed integrally and a pressure-receiving member made of a resilient material is attached to the front portion of the machine frame of the label printing machine. In this mechanism, label printing is effected only when the pressure roller attached to the free end of printing lever rides over the pressure receiving member in the downward movement of the printing lever.

Meanwhile, it has become necessary in recent years to read information printed on labels optically since P.O.S. (point of sales) systems have been widely adopted. Therefore, the labels must be printed quite precisely because they must be acceptable for optical character reading. For this purpose, it has become necessary to provide the label printing machine with two or more inking rollers so as to apply ink evenly to the type faces of a printing head, or with a guide means for pushing inking rollers so as to roll the rollers over type faces under a constant pressure.In the above label-printing machine, the front portion of machine frame, that is to say, the space in front of the printing head, is occupied by the above-mentioned pressure receiving member, and it is therefore impossible to provide two or more inking rollers or the above-mentioned guide means for pressing inking rollers against type faces with a certain pressure in order to apply ink to the type faces evenly and properly.

Furthermore, the structure of label-printing machine becomes complicated if such constant printing pressure mechanism is installed and the label-printing machine becomes expensive for general users.

The present invention provides a labelprinting machine comprising a printing head attached to a printing lever which is secured to or formed integrally with a hand lever, a platen which is disposed opposite to the printing head, a hand grip disposed opposite to the hand lever, and a constant printing pressure mechanism comprising: a supporting member which is attached to the hand lever; a prcssure-controlling member which is pivotally secured to the hand lever and biased, by a resilient member interposed between the supporting member and the pressure-controlling member, against a stop away from which the pressure-controlling member can turn only in a direction towards the supporting member; a pressure-receiving piece which is provided with a cam surface on the side thereof that is remote from the supporting member, pivotally secured to the pressurecontrolling member and resiliently biased against a stop on the pressure-controlling member away from which the pressurereceiving piece can turn only towards the hand grip; and a pressure-applying member which is attached to the hand grip; the arrangement being such that in use the hand lever and the hand grip can be squeezed together, bringing the cam surface of the pressure-receiving piece into contact with the pressure-applying member, and if a predetermined squeezing force is applied to the hand lever and the hand grip the cam surface of the pressure-receiving piece rides over the pressure-applying member, the pressurereceiving piece moving with it the pressurecontrolling member against the force of the resilient member, and the printing head then comes into contact with a label on the platen to print the label.

One form of label-printing machine constructed in accordance with the invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a side view of the label-printing machine with the nearside machine frame removed and the machine in its rest position; Fig. 2 is a side view of the label-printing machine with a portion of the machine frame removed and the machine in the pressurereceiving state; Fig. 3 is a side view of the label-printing machine with a portion of the machine frame removed and the machine in the printing state; and Fig. 4 is an exploded perspective view of the constant printing pressure mechanism of the label-printing machine.

Referring to the accompanying drawings, the label-printing machine includes a constant printing pressure mechanism, which is indicated generally by the reference letter A and is mounted on the rear end portion of the machine, that is to say, on the rear free end of a hand lever 1, as shown in Fig. 1. The mechanism A mainly comprises a supporting member 2, a pressure-controlling member 3 and a pressure-receiving piece 4, which are shown in detail in Fig. 4.

The supporting member 2 is formed integrally with the rear end of the hand lever 1 and in the upper part of the supporting member 2 are formed a longitudinal screw hole 5 and a spring hole 6 having a diameter larger than that of the screw hole 5. The above two holes 5 and 6 are continuous and pass through the body of the supporting member 2.

In the lower part of the pressure-controlling member 3, a bearing hole 49 is formed and the pressure-controlling member 3 is pivotally secured between the side walls la of the hand lever 1 by a shaft 21 which is inserted into the bearing hole 49. In the upper portion of the pressure-controlling member 3, a recess 7 having a raised stage 7a is defined with a pair of side plates 8 which have pin holes 9, respectively. The front lower portion (the left and near side as seen in Fig. 4) of the pressurecontrolling member 3 is provided with a raised stopper 10 and the rear surface of the member 3 is provided with a spring hole 11 which is similar to the hole 6 of the supporting member 2.

The pressure-receiving piece 4 is provided with a cam surface 12 in the front side and a recess 13 in the rear side thereof. In the side walls 14 on both sides of the recess 13, pin holes 15 are formed. This pressure receiving piece 4, is pivotally received within the recess 7 of the pressure-controlling member 3 and is actuated by a spring. That is, a pin 16 is inserted into the pin holes 9 and other pin holes 15, and a return spring 17 is fitted to the pin 16 so as to urge the pressure receiving piece 4 counterclockwise as seen in the drawings. Thus, the cam surface 12 is urged forward.

An adjusting screw 18 is fitted into the screw hole 5 of the above-mentioned supporting member 2. An adjusting spring 19 is set in the spring hole 6 of the supporting member 2 and another corresponding spring hole 11 of the pressure-controlling member 3, and the rear end of the adjusting spring 19 is urged against the front face of the adjusting screw 18 by interposing a spring holding member 20 therebetween. Accordingly, the force of the adjusting spring 19 against the pressure controlling member 3 can be regulated by moving the adjusting screw 18 back and forth.

In the following, the label-printing machine having the constant printing pressure mechanism will be described with reference to Figs.

1 to 4.

In the upper portion of the space between a pair of machine frames 24 on both sides of the machine body, a printing lever 23 consisting of two side plates is provided. The rear ends of the printing lever 23 is pivotally secured to the rear portions of the machine frames 24 by means of a pivot shaft 25. In further rear side of the printing lever 23, there is integrally formed a hand lever 1. The reference numeral 26 indicates a return spring which acts in tension between the spring pin 30 fixed on the rear part of the hand grip 22 and the spring hole 31 that is defined in the rear portion of the printing lever 23. By the return spring 25, both the printing lever 23 and the hand lever 1 are always urged clockwise as seen in the drawings. The free end portion of the printing lever 23 is provided with a printing head 27.

Further, a pair of swingable arms 32 is pivotally secured to the outside surfaces of the front end of the printing lever 23 and to the lowermost ends of the arms 32 are attached an inking roller holder 35 that carries rotatable inking rollers 33 and 34. On both sides of this inking roller holder 35, guide rollers 36 and 37 are attached at the positions corresponding to the above inking rollers 33 and 34, respectively. In order to guide these guide rollers 36 and 37, guide grooves 38 and 39 are formed in the inside walls of the machine frames 24.

The reference numeral 40 in Fig. 1 indicates a label supporting device for rotatably supporting a rolled label strip 41. The refer- ence numeral 42 denotes a feeding device which passes a tape-like strip 43 from the rolled label strip 41 to a platen 44 and the numeral 50 indicates a label applicator.

On both sides around the spring pin 30 that is formed on the inside of the hand grip 22, pressure rollers 45 are rotatably fitted so as to be brought into contact with the cam surface 12 of the pressure-receiving piece 4.

Then, the function of the constant printing pressure mechanism A of the present invention will be described with reference to Figs.

1 to 3.

When the hand grip 22 and the hand lever 1 in the rest position shown in Fig. 1 are squeezed together, the printing lever 23 is turned counterclockwise as seen in the drawings (or downward) about the fulcrum of the pivot shaft 25. In this action, the swingable arms 32 are turned clockwise as seen in the drawings and the inking roller holder 35 carried by the arms 32 is moved forward.

Thus, the inking rollers 33 and 34 are rolled on the faces of types 28 that are disposed on the underside of the printing head 27, thereby applying ink to type faces. Since the aforementioned guide rollers 36 and 37 are moved along the guide grooves 38 and 39 in this inking action, the inking rollers 33 and 34 are rolled on the faces of types 28 while exerting a constant pressure so that ink can always be applied to the type faces evenly.

When the hand lever 1 is then squeezed further, the hand lever 1 and the hand grip 22 come near to each other and, as shown in Fig. 2, the upper front portion of the cam surface 12 formed on the pressure-receiving piece 4 of the constant printing pressure mechanism A is brought into contact with the lower sides of the pressure rollers 45 that are attached to the spring pin 30 in the hand grip 22. In this action, because the lower rear sides of the pressure rollers 45 forcibly push the upper front portion of the cam surface 12, the pressure-receiving piece 4 is subjected to a counterclockwise force, but the pressure-receiving piece 4 is not turned counterclockwise (as seen in the drawings) at all because the under surface 46 of the pressure-receiving piece 4 is held in contact with the bottom surface 47 in the recess 7 of the pressure controlling member 3.As a result, the above-described pressure is directly applied to the pressure-controlling member 3.

The bearing hole 49 of the pressure-controlling member 3 is pivotally secured to the side walls la of the hand lever 1 by means of the shaft 21. In addition, the stopper 10 is in contact with the upper surface of the hand lever 1, so that it can be turned only in the clockwise direction as seen in the drawings.

Therefore, as shown in Fig. 2, the pressurecontrolling member 3 is slightly turned clockwise as seen in the drawings (rearward) about the fulcrum of shaft 21 against the force of the adjusting spring 19 by the pressure of the above-mentioned pressure rollers 45. When the force with which the hand grip 22 and the hand lever 1 are squeezed exceeds the force of the adjusting spring 19, the cam surface 12 rides over the rear sides of the pressure rollers 45. That is to say, the hand lever 1 can be squeezed further.

When the hand lever 1 is fully squeezed as shown in Fig. 3, the printing head 27 is further moved downwards and the types 28 are brought into contact with the label strip 43 that is carried on the platen 44. Simultaneously with this printing of the label 43, the inking roller holder 35 and inking rollers 33 and 34 are shifted forward along the guide grooves 38 and 39 and they are pushed out on the front side of the machine body.

In the next step, when the hand lever 1 is released, the printing lever 23 is returned to the rest position of Fig. 1 by the contraction of the return spring 26.

In this operation, the pressure-receiving piece 4 is turned clockwise because the curved surface 29 below the cam surface 12 comes into contact with the pressure rollers 45 and is guided by them. More particularly, since the pressure-receiving piece 4 is provided with a rounded surface 48 on its lower rear side, the pressure-receiving piece 4 is smoothly turned clockwise as seen in the drawings about the pin 16 against the force of the return spring 17. Accordingly, the hand lever 1 can be returned into the rest position of Fig. 1 without receiving any resistance.

Further, the force of the adjusting spring 19 against the pressure-controlling member 3 can be controlled by moving the abovementioned adjusting screw 18 within the screw hole 5 of the supporting member 2 back or forth, so that the intensity of squeezing that is necessary for the printing can be well controlled. It should be noted that the adjusting spring 19 can be replaced by any other means having a corresponding function.

In the label-printing machine shown in the accompanying drawings, a label is printed pnly when the squeezing force applied to the hand lever exceeds the action of the adjusting spring, so that the following advantages can be expected.

(1) When the hand lever is squeezed too strongly, the force of squeezing is properly weakened by the pressure-receiving piece.

When the hand lever is squeezed weakly, the force of squeezing is accumulated and the printing is actuated only when the force of squeezing exceeds a certain level. Accordingly, the label printing is always performed at a constant pressure and high precision printing without uneveness in the depth of printed figures can be attained successfully.

(2) Since the constant printing pressure mechanism is mounted on the rear part of a label-printing machine, it does not obstruct the space in the front portion of a printing head and accordingly, it becomes possible to attach a plurality of inking rollers so as to apply ink to the type faces of the printing head. Further, the space can also receive the pushing and guiding means for inking rollers.

Therefore, the type faces are applied with ink fully and evenly and quite clear printing can be always carried out.

(3) Since the constant printing pressure mechanism is mounted on the rear part of a label printing machine, the space in front of a label applicator is not obstructed and it becomes easy to apply printed labels to desired portions of articles.

(4) Further, some portions of the hand lever and hand grip are utilized for the constant printing pressure mechanism can be made simple and, accordingly, constant pressure label printing machines can be produced at a relatively low cost.

This constant printing pressure mechanism is especially suitable for a label-printing machine intended for printing optically readable figures on labels for use in the aforementioned P.O.S. system.

WHAT WE CLAIM IS:- 1. A label-printing machine comprising a printing head attached to a printing lever which is secured to or formed integrally with a hand lever, a platen which is disposed opposite to the printing head, a hand grip disposed opposite to the hand lever, and a constant printing pressure mechanism comprising: a supporting member which is attached to the hand lever; a pressurecontrolling member which is pivotally secured to the hand lever and biased, by a resilient member interposed between the supporting member and the pressure-controlling member, against a stop away from which the pressurecontrolling member can turn only in a direction towards the supporting member; a pressure-receiving piece which is provided with a cam surface on the side thereof that is remote from the supporting member, pivotally secured to the pressure-controlling member and resiliently biased against a stop on the pressure-controlling member away from which the pressure-receiving piece can turn only towards the hand grip; and a pressure-applying member which is attached to the hand grip; the arrangement being such that in use the hand lever and the hand grip can be squeezed together, bringing the cam surface of the pressure-receiving piece into contact with the pressure-applying member and if a predetermined squeezing force is applied to the hand lever and the hand grip the cam surface of the pressure-receiving piece rides over the pressure-applying member, the pressure-receiving piece moving with it the pressure-controlling member against the force of the resilient member, and the printing head then comes into contact with a label on the platen to print the label.

2. A label-printing machine as claimed in claim 1, wherein the pressure-controlling member is provided with a recess to receive the pressure-receiving piece therein.

3. A label-printing machine as claimed in claim 1 or claim 2, wherein the resilient member is a helical spring, the compression of which can be controlled by means of an adjusting screw.

4. A label-printing machine as claimed in any one of claims 1 to 3, wherein the pressureapplying member is a roller which is attached to a pin formed on the inside wall of the hand grip.

5. A label-printing machine substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. clockwise as seen in the drawings about the pin 16 against the force of the return spring 17. Accordingly, the hand lever 1 can be returned into the rest position of Fig. 1 without receiving any resistance. Further, the force of the adjusting spring 19 against the pressure-controlling member 3 can be controlled by moving the abovementioned adjusting screw 18 within the screw hole 5 of the supporting member 2 back or forth, so that the intensity of squeezing that is necessary for the printing can be well controlled. It should be noted that the adjusting spring 19 can be replaced by any other means having a corresponding function. In the label-printing machine shown in the accompanying drawings, a label is printed pnly when the squeezing force applied to the hand lever exceeds the action of the adjusting spring, so that the following advantages can be expected. (1) When the hand lever is squeezed too strongly, the force of squeezing is properly weakened by the pressure-receiving piece. When the hand lever is squeezed weakly, the force of squeezing is accumulated and the printing is actuated only when the force of squeezing exceeds a certain level. Accordingly, the label printing is always performed at a constant pressure and high precision printing without uneveness in the depth of printed figures can be attained successfully. (2) Since the constant printing pressure mechanism is mounted on the rear part of a label-printing machine, it does not obstruct the space in the front portion of a printing head and accordingly, it becomes possible to attach a plurality of inking rollers so as to apply ink to the type faces of the printing head. Further, the space can also receive the pushing and guiding means for inking rollers. Therefore, the type faces are applied with ink fully and evenly and quite clear printing can be always carried out. (3) Since the constant printing pressure mechanism is mounted on the rear part of a label printing machine, the space in front of a label applicator is not obstructed and it becomes easy to apply printed labels to desired portions of articles. (4) Further, some portions of the hand lever and hand grip are utilized for the constant printing pressure mechanism can be made simple and, accordingly, constant pressure label printing machines can be produced at a relatively low cost. This constant printing pressure mechanism is especially suitable for a label-printing machine intended for printing optically readable figures on labels for use in the aforementioned P.O.S. system. WHAT WE CLAIM IS:-

1. A label-printing machine comprising a printing head attached to a printing lever which is secured to or formed integrally with a hand lever, a platen which is disposed opposite to the printing head, a hand grip disposed opposite to the hand lever, and a constant printing pressure mechanism comprising: a supporting member which is attached to the hand lever; a pressurecontrolling member which is pivotally secured to the hand lever and biased, by a resilient member interposed between the supporting member and the pressure-controlling member, against a stop away from which the pressurecontrolling member can turn only in a direction towards the supporting member; a pressure-receiving piece which is provided with a cam surface on the side thereof that is remote from the supporting member, pivotally secured to the pressure-controlling member and resiliently biased against a stop on the pressure-controlling member away from which the pressure-receiving piece can turn only towards the hand grip; and a pressure-applying member which is attached to the hand grip; the arrangement being such that in use the hand lever and the hand grip can be squeezed together, bringing the cam surface of the pressure-receiving piece into contact with the pressure-applying member and if a predetermined squeezing force is applied to the hand lever and the hand grip the cam surface of the pressure-receiving piece rides over the pressure-applying member, the pressure-receiving piece moving with it the pressure-controlling member against the force of the resilient member, and the printing head then comes into contact with a label on the platen to print the label.