Traveling thread-joining device

In a thread-joining device capable of traveling from spinning station to spinning station of a spinning machine having respective means for feeding sliver thereto, a device for measuring a dimension of the sliver at the respective feeding means of the spinning stations.

The invention relates to a traveling thread-joining or piecing device for 
spinning machines, especially rotor spinning machines. 
There are many causes for thread breaks at spinning machines. Included 
therein are causes of thread breaks wherein, from the very start, a 
joining attempt of a traveling joining device cannot succeed. Such causes 
are when the sliver can runs empty, when there is an interruption in the 
sliver feed, when feed of a sliver having too great a cross section 
occurs, for example, in the form of a double loop, with externally 
non-visible interruption of the sliver feed in the interior of the 
spinning station housing. 
It is accordingly an object of the invention to provide a traveling 
thread-joining device which is prevented from being activated from the 
very start in each of the foregoing cases. 
With the foregoing and other objects in view, there is provided, in 
accordance with the invention, in a thread-joining device capable of 
traveling from spinning station to spinning station of a spinning machine 
having respective means for feeding sliver thereto, a device for measuring 
a dimension of the sliver at the respective feeding means of the spinning 
stations. Such a measuring device can advantageously block the 
thread-joining mechanism or permit the thread-joining device to travel 
farther if the measuring result affords the expectation of a purposeful 
thread-joining attempt. 
In accordance with another feature of the invention, the thread-joining 
device includes means for actuating the measuring device during travel 
thereof for measuring the dimension of the sliver at the respective 
feeding means therefor. 
The measuring device need not be constructed so as to determine exact or 
absolute dimension values. It is sufficient, in accordance with a further 
feature of the invention, to provide the measuring device with means for 
differentiating at least the sliver dimension "normal cross section", 
"greater than normal cross section" and "smaller than normal cross section 
or absence of sliver altogether". 
In accordance with an added feature of the invention, the measuring device 
comprises mechanical sensing means displaceable on the sliver, and a 
channel member partly cut open for passage of the sensing means 
therethrough, the sliver being guidable in the channel member with 
established, substantially uniform dimensions. The sliver can be 
introduced, for example, from below toward the top into the spinning 
stations. As it travels past the thread-joining device, sensing means 
slide on and along the sliver sled-like transversely to the feeding 
direction of the sliver. The sensing means can also be rollable on and 
along the sliver, for example in direction of feed thereof, so that the 
sliver cannot be braked by the sensing means in feeding direction. The 
channel members are cut open partly only to an extent that the sensing 
means can be guided measuringly over the sliver in the slot formed 
thereby. 
In accordance with an additional feature of the invention, the mechanical 
sensing means are operatively connected to a three-position switch. The 
three switch positions correspond to the aforementioned three sliver 
characteristics that are to be determined. The traveling thread-joining 
device is constructed so that it is activated at a spinning station which 
has issued a demand for thread-joining only if the sliver has a normal 
dimension i.e. "normal cross section". Only then is there an adequately 
great likelihood that thread-joining attempts also will be successful. 
In accordance with yet another feature of the invention, one of the 
positions of the three-position switch corresponds to the sliver dimension 
"less than normal cross section" and another of the positions thereof to 
the sliver dimension "greater than normal cross section", and means are 
included for effecting signal connections of the one and another positions 
of the switch to a signaling device at a respective spinning station. 
These signal connections need not always be present and it is sufficient 
that they be present only when the thread-joining device travels past the 
respective spinning station. The signal connections can accordingly be 
formed, for example, of electrical connections employing proximity 
switches. It is recommendable to provide two signaling or indicating 
devices at each spinning station, one of which is responsive to the signal 
"smaller than normal cross section" and the other to the signal "greater 
than normal cross section". In a somewhat more simplified construction, 
one signaling or indicating device is sufficient and, correspondingly, 
only one signal connection for each spinning station. 
In accordance with a concomitant feature of the invention, the third of the 
positions of the three-position switch corresponds to the sliver dimension 
"normal cross section", and the thread-joining device includes a 
travel-mechanism motor for driving the thread-joining device, means for 
switching off the motor and simultaneously starting a thread-joining 
program of the thread-joining device, pawl means actuatable by the 
operative connection through the three-position switch to the mechanical 
sensing means of the measuring device for switching off the motor and 
starting the thread-joining program only when the switch is in the third 
position thereof and a signaling or indicating device at the respective 
spinning station signals or indicates "thread-joining required". This 
operative connection is also required to be present only when the 
thread-joining device travels past the respective spinning station. Also 
in this case, proximity switches, for example, can be employed. 
The advantages derived from the invention are especially that superfluous 
thread-joining attempts can be obviated from the start, the 
sliver-measuring device being provided only once for a major section of 
the spinning machine, namely as a part of the automatic thread-joining 
device. 
Other features which are considered as characteristic for the invention are 
set forth in the appended claims. 
Although the invention is illustrated and described herein as embodied in a 
traveling thread-joining device, it is nevertheless not intended to be 
limited to the details shown, since various modifications and structural 
changes may be made therein without departing from the spirit of the 
invention and within the scope and range of equivalents of the claims.

Referring now to the drawing and first, particularly, to FIG. 1 thereof, 
there is shown a spinning station 11 and a traveling thread piecing or 
joining device 12 that has stopped in front of the spinning station 11 and 
has clicked into suitable engagement therewith. A block diagram of a 
measuring device 13 constructed in accordance with the invention is also 
illustrated in FIG. 1. 
As is further shown in FIG. 1, a sliver supply 16 for the spinning station 
11 is provided with a sliver-guiding channel member or gutter 19, 19a 
having a notch 18 formed therein. Two proximity switches 20 and 21 are, 
furthermore, provided at the spinning station 11. A line 22 leads from the 
proximity switch 20 to a signaling device 23, and a line 24 from the 
proximity switch 21 to another signaling device 25. The signaling device 
23 serves for signaling "sliver cross section too small" and the signaling 
device 25 "sliver cross section too large" to the servicing or operating 
personnel. Another signaling device 26 formed of an electromagnetic drive 
27 with a switching armature 28 serves to signal "joining or piecing 
required" to the joining or piecing device 12. 
In the somewhat simplified top plan view of the spinning stations 11, 14 
and 15 according to FIG. 2, it is apparent that the sliver 17 at the 
spinning station 11 has a normal cross section, the sliver 29 has run into 
the channel 30 of the spinning station 14 with approximately three times 
the normal cross section, such as that of the sliver 17, and the channel 
31 of the spinning station 15 contains no sliver at all. 
The piecing or joining device 12, which is of conventional construction and 
requires no detailed description herein since the specific construction 
thereof forms no part of the invention of the instant application, has two 
sets of supporting drive rollers 32, 33 disposed on rails 34, 35. The one 
drive roller 33 has a shaft 36 which carries a gear 37 that is connected 
by an endless chain 38 to another gear 39 which is seated on a driven 
shaft of a travel-mechanism motor 40. 
A support beam 41 on which the rails 34, 35 are fastened has a stop or 
detent 42 located in front of the spinning station 11. Similar stops are 
also disposed in front of each of the other spinning stations. As shown in 
FIG. 1, a pawl 43, which is pivotable about an articulating joint or pivot 
pin 44 and is actuatable by a switching armature or plunger 45 of an 
electromagnet drive 46, is in engagement with the stop 42. 
The measuring device 13 is articulatingly fastened to a bracket or console 
47. It is formed of a lever 48 with a slide or cradle-like sensor 49 and 
another lever 50 with a contact vane 51. Depending upon the position or 
setting of the sensor 49, the contact vane 51 engages one of the three 
contacts 53, 54 and 55 of a three-position switch 52. A lead 56 extends 
from the contact 53 of the switch 52 to an electromagnet drive 57, and a 
lead 58 from the contact 55 to an electromagnet drive 59. A line or lead 
60 extends from the middle contact 54 of the three-position switch 52 to 
an input of an AND-gate 61. Another lead 62 extends from a proximity 
switch 63 likewise to an input of the AND-gate 61. The output of the 
AND-gate 61 is connected by a line 64 to a switching device 65. 
Since the sensor 49 of the measuring device 13 due to the relatively great 
projection thereof on both sides, has already determined the normal 
structure of the sliver 17, as shown in FIG. 2, even before the stop 
position has been reached, the contact vane 51 is already disposed on the 
contact 54 when the proximity switch 63 comes into the vicinity of the 
outwardly driven switching armature 28 of the electromagnet drive 27 as 
the piecing or joining device 12 travels past. Since, in this instant, a 
signal has reached the AND-gate 61 both over the lead 60 as well as over 
the lead 62, the AND-condition has been fulfilled, and the switching 
device 65 receives a command over the lead 64 to stop the travel-mechanism 
motor 40, to engage the pawl 43 with the respective stop and to start the 
conventional thread piecing or joining program. The command to stop goes 
over the lead or line 66 to the travel-mechanism motor 40, the 
pawl-engagement command over the line 67 to the electromagnet drive 46 of 
the pawl 43, and the start command for the piecing or joining program over 
the line 68 to a conventional non-illustrated program switching mechanism. 
The electromagnet drives 57 and 59 are not switched on at the existing 
setting or position of the three-pole switch 52, and the switching 
armatures 69 and 70, respectively, of the electromagnet drives 57 and 59 
are accordingly withdrawn. The proximity switches 20 and 21 have, 
therefore, not responded, and a disturbance or disruption signal is not 
received. 
The course of the rails 34 and 35 along the spinning machine is apparent 
from FIG. 2. The piecing or joining device 12 travels in direction of the 
double-headed arrow 71.