Device for intermittently transporting a label bearing tape in a manually operated labeler

An apparatus is described by which a label bearing tape can be transported intermittently in a manually operated labeler. The device contains a transporting carriage (19) reciprocable along the label bearing tape (5). In the carriage a latch (22) with a clamping face (25) is held in frictional engagement with the label bearing tape so that during movement of the carriage in one direction it freely slides on the label bearing tape, while during movement of the carriage in the other direction it clamps the label bearing tape against an abutment surface (26) with self-locking action. The clamping face of the latch is covered with abrasive paper, preferably with an aluminous abrasive paper.

The invention relates to a device for intermittently transporting a label 
bearing tape in a manually operated labeler, said device including a 
transportating carriage reciprocable along the label bearing tape and 
holding a latch with a clamping face in frictional engagement with the 
label bearing tape so that during movement of the carriage in one 
direction it freely slides on the label bearing tape, and during movement 
of the carriage in the other direction it clamps the label bearing tape 
against an abutment surface with self-locking action. 
Such a transporting device has been known from German patent application 
No. 1,944,857. In this known device the clamping face is the end face of 
an elastic clamping member which is held in frictional engagement with the 
label bearing tape. When in the known device the carriage commences to 
move in the direction where the latch comes into self-locking engagement 
with the label bearing tape, the elastic clamping member urges the tape 
against the abutment surface, and upon the increasing tensile force 
exerted by the carriage on the tape, which finally results in the actual 
transportation of the tape, the clamping member undergoes elastic 
deformation with ensuing relative movement between the carriage and the 
label bearing tape. This relative movement due to elastic deformation of 
the clamping member depends on various factors that cannot be precisely 
determined, e.g. on the elasticity of the clamping member which may vary 
with the operating temperature, or on the speed at which the carriage is 
moved. The undesirable consequence of relative movement between the 
carriage and the label bearing tape are slightly different lengths of 
transportation which have a very unfavorable effect particularly when 
prior to being dispensed from the manual labeler the labels are to be 
printed. The exact positioning of the imprint on the label depends on the 
exact length of transportation of the tape, i.e. each label to be printed 
must be positioned in exactly the same place within the device, after 
performance of one advancing cycle. 
The invention is concerned with the problem of designing a device of the 
initially described type so that with simple construction a very precise 
and, above all, an exactly reproducible length of tape advance is 
achieved. 
According to the invention, this problem is solved in that the clamping 
face of the latch is covered with abrasive paper. With this embodiment of 
the device of the invention there is substantially no relative movement 
between the carriage and the tape, after the latch has come into 
self-locking engagement with the tape. Very soon after commencement of 
self-locking engagement between the clamping face and the tape surface the 
clamping face is fully in contact with the tape so as to exclude relative 
movement therebetween. Any still possible relative movement can take place 
only between the instant when the tips of the abrasive particles of the 
clamping face start to contact the tape and the instant when the abrasive 
particles fully cut into the tape surface. Since the abrasive particles 
are of very small height, the still possible relative movement is so 
slight that it may be fully neglected for practical purposes. 
Preferably the abrasive paper is an aluminous abrasive paper which is 
especially resistant to wear and thus ensures a long lifetime of the 
clamping face.

The manual labeler shown in FIG. 1 serves to print adhesive labels and to 
provide them on articles for sale. The labeler includes a housing 1 
provided with a handle 2. In the top of the housing a cavity 3 is provided 
for receiving a supply roll 4 of a backing tape 5 with adhesive labels 6 
adhering thereto. The tape 5 in the labeler runs from the cavity 3 first 
downwardly and then forwardly to a dispensing edge 7 where the backing 
tape 5 is deflected and passed through a transporting device 8 to the rear 
end of the housing. In front of the dispensing edge 7 an applicator roll 9 
is mounted for rotation in the housing in order to permit adhesion of a 
label 6' separated from the tape and ready in dispensing position to be 
adhered to an article. 
Below the handle 2 there is an operating lever 10 mounted for rotation 
about the shaft 11. Between the handle 2 and the operating lever 10 there 
is a spring 12 constantly tending to urge the lever into the inoperative 
position shown in FIG. 1. In the housing 1 there is also a printer lever 
13 likewise mounted for rotation about the shaft 11. The printer lever 13 
carries a printer 14 by means of which an adhesive label 6 resting on a 
printing platen 15 can be printed. Between an arm 16 of the operating 
lever 10 and the printer lever 13 a spring 17 is provided which serves to 
transmit to the printer lever 13 the movement of the operating lever 10 
toward the handle 2. In the inoperative position shown in FIG. 1 the 
printer lever 13 is held in its lifted position by a projection 18 at the 
operating lever 10. 
The transporting device 8 is so positioned in the housing 1 that it can 
move between a rearward end position and a forward end position. In FIG. 1 
the transporting device 8 is in its rearward end position. The 
transporting device 8 includes a carriage 19 at the rear end of which two 
pins 20 extend toward the respective sidewalls of the housing 1. Said pins 
20 slide in elongate slots 21 in sidewall panels of the housing 1. The 
elongate slots 21 limit the path of the transporting carriage 19 forwardly 
and rearwardly. Moreover, the transporting device 8 comprises a latch 22 
mounted for rotation about a shaft 23 provided in the carriage 19. A 
torsion spring 24 provided on the shaft 23 tends to rotate the latch 
clockwise in the view of FIG. 1. In this way a clamping face 25 provided 
at the latch 22 is held in frictional engagement with the tape 5 passed 
through the carriage 19, while the tape 5 is supported by an abutment 
surface 26 provided at the carriage 22. The clamping face 25 is covered 
with abrasive paper, preferably with aluminous abrasive paper. A synthetic 
resin-bonded aluminous abrasive paper with abrasive particles embedded in 
synthetic resin is especially favorable. 
Near the exit 27 of the tape 5 from the housing 1 there is a further latch 
28 which likewise has an aluminous abrasive paper covered clamping face 
28a and cooperates with an abutment surface 29 at the housing. This latch 
28 is under load of a torsion spring 30 so that it is held in contact with 
the backing tape 5 resting on the abutment surface 29. The latch 28 
permits movement of the backing tape 5 toward the exit 27 while it 
prevents movement of the backing tape in the opposite direction. 
When the operating lever 10 is pulled toward the handle 2 against the force 
of the spring 12, the movement of the operating lever 10 counterclockewise 
about the shaft 11 is transmitted to the printer lever 13 by way of the 
arm 16 and the spring 17. The printer lever 13 therefore likewise rotates 
counterclockwise about the shaft 11 thereby lowering the printer 14 in the 
direction of the arrow 31 onto the printing platen 15. By way of a lever 
connection, not shown, the transporting device 8, in the view of FIG. 1, 
is shifted along the backing tape 5 to the left upon the movement of the 
printer lever 13. The latch 22 slides on the surface of the backing tape, 
while the latch 28 grips the backing tape 5 so that it cannot be carried 
along by the transporting device 8. When next the operating lever 10 is 
released it returns to its initial position shown in FIG. 1. By the action 
of the projection 18 on the printer lever 13 the latter is returned to its 
lifted position. At the same time the lever connection, not shown, returns 
the transporting device 8 to its starting position on the right-hand side 
in FIG. 1. During said movement the latch 22 held in contact with the 
backing tape 5 by the torsion spring 24 urges the tape against the 
abutment surface 26, and in the course of said movement the latch 22 comes 
into self-locking engagement with the backing tape 5 so that the tape 5 is 
carried along with the transporting device 8. The term "self-locking" as 
used in this context means that the engagement between the latch 22 and 
the backing tape 5 becomes the firmer the more tension is exerted by the 
transporting device 8 on the backing tape 5. Due to the sharp deflection 
of the backing tape 5 at the dispensing edge 7 the adhesive label 6 just 
printed by the printer 14 separates from the backing tape and arrives in 
the dispensing position, i.e. the position of the label 6' shown in FIG. 
1. In this position the adhesive label 6' can be applied on an article by 
rolling the applicator roll 9 over the article. 
FIG. 2 shows the transporting device 8 in its rearward end position which 
it assumes after it has transported into the dispensing position an 
adhesive label previously printed on the printing platen 15. In FIG. 3 the 
transporting device 8 is in its forward end position which it assumes when 
the operating lever 10 is fully drawn toward the handle 2 and the printing 
head 14 is just printing an adhesive label on the printing platen 15. The 
length of movement of the transporting device 8 determined by the length 
of the elongate slots 21 exactly corresponds to the length of one adhesive 
label 6 plus an overstroke allowed for safety's sake. 
When the operating lever 10 is released and the transporting device 8 
returns from its end position shown in FIG. 3 to the initial position, the 
latch 22 moves from its released position shown in FIG. 3 in which it 
freely slides over the backing tape surface to its clamping position shown 
in FIG. 2. The torsion spring 24 takes care that immediately after the 
reversal of movement of the transporting device 8 the latch 22 assumes the 
self-locking clamping position for advance of the backing tape by exactly 
the length of one label. As mentioned above, the clamping face is covered 
with abrasive paper which ensures very precise engagement between the 
clamping face and the backing tape surface. The use of abrasive paper on 
the clamping face permits perfect engagement between the clamping face and 
the backing tape in a very short time because the abrasive particles 
project only little above the surface of the abrasive paper. Therefore, 
after initial contact between the tips of the abrasive particles and the 
surface of the backing tape there is very little movement of the clamping 
face relative to the backing tape so that said full engagement during 
which the backing tape is in intimate contact with the abrasive paper is 
reached very quickly. Consequently, during the movement of the 
transporting device in the direction of advance, i.e. from the forward end 
position into the rearward end position, only very little relative 
movement between transporting device and backing tape can take place. This 
ensures very high positioning accuracy of the adhesive labels on the 
printing platen. 
The abrasive paper covering the clamping face 25 hardly tends to pick up 
any of the adhesives normally used for adhesive labels. Therefore, 
residual adhesive which may build up on the abutting surface 26 in the 
course of operation of the labeler and which may be present also on the 
back side of the backing tape 5 coming into contact with the clamping face 
25, will hardly soil the clamping face 25. Since thus no residues of 
adhesive build up on the clamping face 25, it cannot happen that the 
clamping face 25 sticks to the abutment surface 26 when the device is 
empty and contains no backing tape. Such adhesion would be highly 
undesirable because then label tape refill could not be readily inserted 
into the device. 
Although the label tapes presently in use have relatively smooth surfaces, 
the wear occurring at the clamping face due to friction must not be 
neglected. The abrasive paper cover on the clamping face 25 has proved to 
be very resistant so that a thus equipped manual labeler remains operable 
for a long period of time without loss of the positioning precision due to 
abating engagement between the clamping face 25 and the backing tape 5.