GB1582363A - Printing device for label printing machine - Google Patents

Description

(54) PRINTING DEVICE FOR LABEL PRINTING MACHINE (71) We, KABUSHIKI KAISHA SATO KENKYUSHO, 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 printing devices for a portable label printing and dispensing machine (hereinafter simply referred to as "label printing machine").

There are generally two kinds of methods to attach a printing device to a label printing machine. In one of them, the printing device is attached to yoke arms which are disposed in the front portion of a hand lever and are swung up and down by the operation of the hand lever. In the other method, the printing device is directly fixed to machine frames. When a label is printed with the former type machine, the printing device is moved down by squeezing a hand lever and a hand grip, and the type faces on the under side of the printing device are brought into contact with a label that is placed on a fixed platen.While, in the other type machine, since the printing device is stationary, the platen carrying a label therein is moved up by the squeezing of a hand lever and a hand grip so as to bring the label into contact with the type faces that are disposed on the under side of the fixed printing device.

In one form of printing device a plurality of endless stamp belts are stretched between rotatable selector wheels and positioning gears in side by side relationship and desired types on the stamp belts are selected and shifted to the printing position by manipulating a selector knob which rotates the above selector wheels.

The above positioning gears are subjected to the action of spring-actuated supporting members.

The spring-actuated supporting members comprise a bridging member that is secured to the frames of the printing device, a plurality of pins, compression springs, and pushing members which are urged down by the compression springs toward the positioning gears. This conventional structure will be further referred to later with reference to the accompanying drawings.

In the above conventional mechanism, since the under surfaces of the pushing members are always pressed against the outer surfaces of the positioning gears by the force of compression springs, the positions of the gears, and accordingly the type faces on the stamp belts, are set to the printing position and held at a predetermined angular arrangement.

In the above mechanism, however, the pushing members are moved vertically about the pins at every turning of the positioning gears. Therefore, the pushing members are liable to become rickety owing to the wearing down of contact surfaces.

Accordingly, the type faces cannot be well maintained in parallel with the surface of the label to be printed. If the label printing is performed with such unparallel arrangement, the depth of printed figures becomes uneven and the printed figures are difficult to read.

Meanwhile, the unclear figures that were printed with such label printing machine have been accepted because they have been used for human readable price indication and it has been only necessary that they can be read with the naked eye when customers buy commodities and cashiers add up the sales.

In recent years, however, what is called P.O.S. (point of sales) system are employed widely in the world, in which machine readable bar codes or optically readable characters printed on labels are read out by optical reading machines that are connected to electronic computers, in place of the above cashiers, and these data of sales and management data such as stock, proceeds, customers relative to every commodities and gains are processed and stored by computers. For the optical character readers, it is necessary to print labels more clearly and precisely as compared with the case of reading with the naked eye.

According to this invention a printing de vice for a portable label printing and dispensing machine comprises spaced side frames, a plurality of endless stamp belts stretched between respective rotatable selector wheels and positioning gears in side by side relationship so as to select and move desired types on said stamp belts to the printing position, a bridging member disposed in the space between the frames, a plurality of elastic supporting members respectively associated with the belts, each supporting member comprising a pin fixed to said bridging member, a pushing member having a recess slidably to receive said bridging member, a hole which is formed in the bottom surface of said recess and slidably receiving said pin and elastic means disposed around said pin and in the space between said bridging member and the bottom surface of said recess, and which biases an under surface of said pushing member into contact with the respective positioning gear.

The invention may be performed in various ways and one specific embodiment will now be described by way of example with reference to the accompanying drawings, in which: - Fig. 1 is an enlarged cross-sectional view of the main part of a printing device in the prior art; Fig. 2 is a partially exploded side elevation of a label printing machine having a printing device according to the present in invention Fig. 3 is a partly exploded side elevation of the printing device according to the invention; Fig. 4 is a vertical cross-sectional view of the same; Fig. 5 is an enlarged perspective view of the main portion of the printing device; Fig. 6 is an enlarged cross-sectional view of the same which is to be compared with the prior art device as shown in Fig. 1;; Figs. 7 (a) and 7 (b) are plan views of printed labels in which the former is printed clearly and the latter is printed unclearly.

For reference purpose, a conventional printing device for a portable label printing machine will be firstly illustrated. In a common label printing machine equipped with either a conventional printing device or the one of the present invention, as shown in Fig. 2, a printing head 3 is attached to yoke arms 4 that are swung down by squeezing a hand grip 1 and a hand lever 2. In another type machine, a printing head 3 is secured to the machine frames 36 and 36' of the label printing machine.

When a label is printed with the former label printing machine, the types or stamps 5 that are disposed on the under side of the printing head 3 are brought into contact with the label which is placed on a platen 6 attached to the machine frames 36 and 36'. In the label printing machine of the latter type, the platen 6 carrying a label is moved up with the operation of the hand lever 2 so that the label on the platen 6 is brought into contact with the faces of types 5 that are disposed on the under side of the printing head 3.

In the common printing head 3 for either a conventional printing device or the one of the present invention, as shown in Figs.

3 and 4, selector wheels 8 are rotated by means of a selector knob 7 and stamp belts 9 travelling around the selector wheels 8 are supported at their lower portions by positioning gears 11. Since the positioning gears 11 are subjected to the action of spring-actuated supporting members 10, the types 5 of stamp belts 9 are held in printing positions and the faces of types 5 are maintained in parallel to the surface of a label to be printed.

The positioning and supporting mechanism for the stamp belts in the conventional art will be described in detail with reference to Fig. 1. A pivot shaft 113 is attached to a pair of frames 120 of a printing head 103 and a plurality of positioning gears 111 are pivotally secured to the shaft 113. The number of the positioning gears 111 is the same as that of stamp belts 109 that travel around the positioning gears 111 in side by side relationship.To the upper sides of the positioning gears 111 are disposed spring-actuated supporting members 110 which comprise a bridging member 114 that is secured in the space between the frames 120, pins 115 the top ends of which are held in the bridging member 114, compression springs 116 fitted around the pins 115, pushing members 118 which have sliding holes 117 to receive the lower portions of the above pins 115 and are urged downward by the compression springs 116 toward the positioning gears 111.

With the above-described mechanism, since the under surfaces of the above pushing members 118 are always pressed against the upper surfaces 119 of the positioning gears 111 by the force of compression springs 116, the positions of the positioning gears 111, accordingly those of the types 105 of stamp belts 109, are correctly set to the printing position and the faces of types 105 are maintained at a predetermined angular arrangement.

In the above-described mechanism, however, the pushing members 118 are lifted 111 and are slid vertically about the pins 115. Therefore, the pushing members 118 at every turning of the positioning gears are liable to become rickety owing to the dimensional errors in working or the wearing down of the outer surfaces of the pins 115 and the inner walls of the sliding holes 117. Accordingly, the faces of types 105 cannot be maintained in parallel with the surface of a label to be printed on the platen. In the case that the label printing is carried out with such unparallel arrangement, the depth in one side of the printed figures becomes different from the depth in the other side of figures as shown in Fig. 7 (b), which makes reading difficult.

The printing device of the present invention has been worked out in view of the above disadvantage caused to occur in the prior art devices.

A printing device according to the present invention will now be described in detail in the following.

The label printing machine shown in Fig.

2 is provided with a printing device, that is a pringting head 3. The rear portions of the machine frames 36 and 36' are elongated (rightward in the drawing) forming a hand grip 1. Below the hand grip 1, a hand lever 2 is pivotally secured to a shaft 35. The front portion of the hand lever 2 is elongated to form a pair of bifurcated yoke arms 4. In the space between the free ends of the yoke arms 4, a printing head 3 is disposed with set screws 34.

As shown in Figs. 3 and 4, this printing head 3 comprises a head casing 19, a pair of frames 20 that are attached to the head casing 19, a front cover 21, a rear cover 22, an angle adjusting section 23 that is attached to the frames 20 and the front cover 21, and side plates 12 that are fixed to a pair of the yoke arms 4 of the label printing machine. Both the above-mentioned front cover 21 and rear cover 22 are attached to both the side plates 12 by means of a shaft 21a and another shaft 22a, respectively. The angle of the faces of types 5 of the stamp belts 9 can be adjusted by manipulating the adjusting screw 24 of the above angle adjusting section 23.

The group of stamp belts 9 are held within the head casing 19 and stretched around selector wheels 8 that are arrayed side by side and positioning gears 11 having springactuated supporting members 10 that are disposed between the frames 20. Each selector wheel 8 is provided with inner teeth 25 which are engaged with an engaging piece 27 that is attached to a selector shaft 26 having a selector knob 7. With this mechanism, any desired selector wheel 8 can be rotated so as to move the stamp belt 9.

Incidentally, each of the stamp belts 9 is an endless type one, a half porton of which is provided with printing types 5 and the remaining half portion, with indicating figures 28. The indicating figures 28 can be observed through a window 29 that is formed in the upper part of the head casing 19.

The positioning and supporting mechanism for the stamp belts 9 is provided in the lower portion of the printing head 3, which mechanism will be described in the following with reference to Fig. 6. The positioning gears 11 are supported in side by side relationship by a pivot shaft 13 which is attached to the frames 20. Formed in each outer side of square positioning gear 11 is an engaging recess 31 which is brought into engagement with engaging projections 30 that are formed on the inside surface of the stamp belt 9.

The spring-actuated supporting members 10 disposed on the positioning gears 11, comprise a bridging member 14 which is fixed to and between the frames 20, pins 15 the upper ends of which are attached to the bridging member 14, compression springs 16 which are disposed around the pins 15, sliding recesses 32 receiving the bridging member 14, sliding holes 17 receiving the pins 15 and communicating with the above sliding recesses 32, and pushing members 18 which are always pressed toward the positioning gears 11 by means of the above-mentioned compression springs 16.

So as to facilitate the smooth turning of the positioning gears 11, a concavity 33 is formed in the under surfaces of each pushing member 18.

The operation of this supporting member will be described in the following.

When a stamp belt 9 is selected and moved round by means of the above-mentioned selector knob 7, the positioning gear 11 is rotated since the engaging recesses 31 of the positioning gear 11 are in engagement with the engaging projections 30 of the stamp belt 9. Since the corner 37 of the positioning gear 11 pushes up the concavity 33 of the pushing member 18 in this operation, the pushing member 18 moves up and then down under the force of the compression spring 16 along the outer surface of the pin 15 and side walls 38 of the bridging member 14. This operation is repeated until a desired type 5 is shifted to the printing position in the lowermost part of the printing head 3.

In comparison with the conventional structure shown in Fig. 1, the printing head 3 is characterized in that the bridging member 14 is made thinner and the pushing members 18 are made taller in which the pins 15 as well as the side walls 38 of the bridging member 14 are slidably engaged.

Since the sliding surfaces of the pushing members 18 are largely increased and the sliding surfaces are elongated in vertical directions, the printing head 3 can be prevented from the influences of the wear of contact surfaces and the dimensional errors in making the device. In other words, even when the same gaps are formed between contact surfaces owing to, for example, the wear of them, the inclination of the under surface of the pushing member 18 in the present arrangement relative to the horizontal plane is very small as compared with the conventional mechanism as shown in Fig. 1, so that the positioning gear 11 that is always depressed by this pushing member 18 and the face of type 5 of the stamp belt 9 in the printing position are well maintained in the correct position.As the result, the printing of a label can be always performed with the type face which is in parallel with the label on the platen 6 and a quite clear and precise imprint without the fluctuation of depth can be obtained as shown in Fig. 7 (a).

Further, the present arrangement is especially advantageous in the case in which a vertically wide area must be printed such as bar code printing (shown in Fig. 7) and multiline printing (not shown).

The printing device is able to maintain the type faces of stamp belts at predetermined correct positions and to attain high precision printing on labels without the fluctuation of the depth of printed figures.

The device can be used for a long period of time without the loss of its performance and reliability, and is not complicated in structure and is produced easily at low cost.

The pushing member is vertically wider than those in the prior art device and it is vertically supported by both the springactuated pin and the side walls of the bridging member; therefore, the pushing member is always moved vertically without any play and the under surface of the pushing member can be always maintained horizontally in parallel with the label surface.

Accordingly, the under surface of the positioning gear together with the lowermost type face can be held in parallel with the label to be printed.

WHAT WE CLAIM IS: - 1. A printing device for a portable label printing and dispensing machine comprising spaced side frames, a plurality of endless stamp belts stretched between respective rotatable selector wheels and positioning gears in side by side relationship so as to select and move desired types on said stamp belts to the printing position, a bridging member disposed in the space between the frames, a plurality of elastic supporting members respectively associated with the belts, each supportng member comprising a pin fixed to said bridging member, a pushing member having a recess slidably to receive said bridging member, a hole which is formed in the bottom surface of said recess and slidably receiving said pin and elastic means disposed around said pin and in the space between said bridging member and the bottom surface of said recess, and which biases an under surface of said pushing member into contact with the respective positioning gear.

2. A printing device for a portable label printing and dispensing machine and substantially as hereinbefore described with reference to and as shown in Figs. 3 to 6 of the accompanying drawings.

3. A portable label printing and dispensing machine including a printing device as claimed in Claim 1 or Claim 2.

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

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. contact surfaces and the dimensional errors in making the device. In other words, even when the same gaps are formed between contact surfaces owing to, for example, the wear of them, the inclination of the under surface of the pushing member 18 in the present arrangement relative to the horizontal plane is very small as compared with the conventional mechanism as shown in Fig. 1, so that the positioning gear 11 that is always depressed by this pushing member 18 and the face of type 5 of the stamp belt 9 in the printing position are well maintained in the correct position.As the result, the printing of a label can be always performed with the type face which is in parallel with the label on the platen 6 and a quite clear and precise imprint without the fluctuation of depth can be obtained as shown in Fig. 7 (a). Further, the present arrangement is especially advantageous in the case in which a vertically wide area must be printed such as bar code printing (shown in Fig. 7) and multiline printing (not shown). The printing device is able to maintain the type faces of stamp belts at predetermined correct positions and to attain high precision printing on labels without the fluctuation of the depth of printed figures. The device can be used for a long period of time without the loss of its performance and reliability, and is not complicated in structure and is produced easily at low cost. The pushing member is vertically wider than those in the prior art device and it is vertically supported by both the springactuated pin and the side walls of the bridging member; therefore, the pushing member is always moved vertically without any play and the under surface of the pushing member can be always maintained horizontally in parallel with the label surface. Accordingly, the under surface of the positioning gear together with the lowermost type face can be held in parallel with the label to be printed. WHAT WE CLAIM IS: -

1. A printing device for a portable label printing and dispensing machine comprising spaced side frames, a plurality of endless stamp belts stretched between respective rotatable selector wheels and positioning gears in side by side relationship so as to select and move desired types on said stamp belts to the printing position, a bridging member disposed in the space between the frames, a plurality of elastic supporting members respectively associated with the belts, each supportng member comprising a pin fixed to said bridging member, a pushing member having a recess slidably to receive said bridging member, a hole which is formed in the bottom surface of said recess and slidably receiving said pin and elastic means disposed around said pin and in the space between said bridging member and the bottom surface of said recess, and which biases an under surface of said pushing member into contact with the respective positioning gear.

2. A printing device for a portable label printing and dispensing machine and substantially as hereinbefore described with reference to and as shown in Figs. 3 to 6 of the accompanying drawings.

3. A portable label printing and dispensing machine including a printing device as claimed in Claim 1 or Claim 2.