U.S. patent application number 12/234084 was filed with the patent office on 2009-04-02 for quick -action tensioning device.
This patent application is currently assigned to Bernstein AG. Invention is credited to Markus Finger, Joachim Ulfik, Werner Winkelhake.
Application Number | 20090083956 12/234084 |
Document ID | / |
Family ID | 38922560 |
Filed Date | 2009-04-02 |
United States Patent
Application |
20090083956 |
Kind Code |
A1 |
Ulfik; Joachim ; et
al. |
April 2, 2009 |
Quick -Action Tensioning Device
Abstract
A tensioning device for at least one cable control switch is
described. The tensioning device includes a holding element for
clamping and securing a cable thereto. A housing is connected to
the holding element. An adjustment device is disposed between the
housing and the holding element to permit adjustment between the
housing and the holding element, thereby permitting a predetermined
tension to be applied to the cable. The device also includes an
electronic device for detecting the tension in the cable and for
generating a signal indicative of the tension.
Inventors: |
Ulfik; Joachim; (Vlotho,
DE) ; Winkelhake; Werner; (Buckeburg, DE) ;
Finger; Markus; (Minden, DE) |
Correspondence
Address: |
BARNES & THORNBURG LLP
750-17TH STREET NW, SUITE 900
WASHINGTON
DC
20006-4675
US
|
Assignee: |
Bernstein AG
Porta Westfalica
DE
|
Family ID: |
38922560 |
Appl. No.: |
12/234084 |
Filed: |
September 19, 2008 |
Current U.S.
Class: |
24/68D |
Current CPC
Class: |
H01H 11/0062 20130101;
H01H 17/08 20130101; H01H 2003/323 20130101; G01L 5/047 20130101;
Y10T 24/2191 20150115; H01H 3/0226 20130101 |
Class at
Publication: |
24/68.D |
International
Class: |
A44B 21/00 20060101
A44B021/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 28, 2007 |
DE |
20 2007 013 591.2 |
Feb 14, 2008 |
DE |
20 2007 013 591 |
Claims
1-7. (canceled)
8. A tensioning device for at least one cable control switch,
comprising: a holding element for clamping and securing a cable
thereto; a housing connected to the holding element; an adjustment
device disposed between the housing and the holding element to
permit adjustment between the housing and the holding element,
thereby permitting a predetermined tension to be applied to the
cable; and an electronic device for detecting the tension in the
cable and for generating a signal indicative of the tension.
9. The tensioning device of claim 8, wherein the electronic device
comprises an optical sensor for detecting the tension on the
cable.
10. The tensioning device of claim 9, further comprising: a bracing
disposed between the housing and the cable, wherein the optical
sensor is disposed in the housing and detects movement of the
bracing.
11. The tensioning device of claim 10, wherein the bracing is
pivotally mounted in the housing.
12. The tensioning device of claim 8, wherein the electronic device
comprises a sensor that detects a direction of movement of the
cable.
13. The tensioning device of claim 8, wherein the electronic device
generates an error signal indicative of a deviation of the tension
from a predetermined setpoint.
14. The tensioning device of claim 13, wherein the predetermined
setpoint comprises a range of setpoints.
15. The tensioning device of claim 8, further comprising a
controller that receives the signal generated by the electronic
device.
16. The tensioning device of claim 15, wherein the controller
generates a signal concerning a deviation of the tension from a
predetermined setpoint based on the signal generated by the
electronic device.
17. The tensioning device of claim 15, further comprising: a
temperature sensor connected to the controller to detect a
temperature and to provide a temperature signal to the controller,
wherein the controller generates an error signal with respect to
the tension on the cable as a function of temperature.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a United States Non-Provisional patent application
that relies for priority on German Patent Application No. 20 2007
013 591.2, filed on Sep. 28, 2007, the contents of which are
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a quick-action tensioning
device for cable control switches, with a holding element to which
a cable can be secured in a clamping manner, and a housing which is
connected to the holding element, means for adjusting being
provided between the housing and holding element in order to set a
predetermined tension.
BACKGROUND OF THE INVENTION
[0003] U.S. Pat. No. 5,003,135 discloses a tensioning device for a
safety switch in which a cable control is secured to an eyelet. The
eyelet is connected to a threaded sleeve into which is screwed a
threaded bolt which is in turn coupled to the safety switch. For
setting the cable tension, an adjustment can be carried out between
the threaded bolt and eyelet. In mechanical quick-action tensioning
devices of this type, there is the problem that a drop in cable
tension or excess tension is detected only relatively late via
optical display means and therefore subsequent tensioning takes
place only when the cable control switch has usually already been
triggered, thus shutting down a machine or production plant. The
maintenance and attention that these quick-action tensioning
devices require are comparatively costly.
[0004] It is therefore the object of the present invention to
provide a quick-action tensioning device for cable control switches
that is easy to maintain and can signal a drop or rise in tension
in good time.
SUMMARY OF THE INVENTION
[0005] It is, therefore, one aspect of the invention to address one
or more of the deficiencies noted above.
[0006] According to the invention, the quick-action tensioning
device has an electronic device for detecting the tension, by means
of which device a signal can be generated to a controller if the
tension deviates from a range of setpoints. It can thus be detected
in good time if the tension of the cable becomes too great or too
slack. Long before a cable control switch is triggered, it is thus
possible to issue a warning in order then to adjust the cable
tension. There is no need optically to monitor the cable tension at
regular intervals.
[0007] For precise detection of the cable tension, the electronic
device preferably comprises an optical sensor. The optical sensor
can in this case be arranged and protected in a housing and can
detect the movement of at least one bracing coupled to the cable.
In this case, the bracing can be pivotably mounted on the housing,
thus allowing a suitable ratio to be set between the cable tension
and pivoting movement.
[0008] According to a further configuration of the invention, the
direction of movement of the cable can also be detected by means of
the sensor. It is thus possible to issue a signal indicating
whether the cable is tensioned too much or too little.
[0009] Preferably, the controller is connected to a temperature
sensor and an error signal with regard to the tension is output as
a function of temperature. Especially in production plants,
temperature fluctuations can occur, so that when a cable is
tensioned for a long time, changes in tension can occur as a result
of fluctuations in temperature. Such changes in tension as a
function of the temperature can be compensated for via the
controller using a temperature sensor, so that changes in tension
based on changes in temperature can be detected but classified as
harmless.
[0010] Other aspects of the invention will be made apparent from
the description that follows and from the drawings appended
hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be described hereinafter in greater
detail based on an exemplary embodiment and with reference to the
appended drawings, in which:
[0012] FIG. 1 is a perspective view of a quick-action tensioning
device according to the invention;
[0013] FIG. 2 is a view of the quick-action tensioning device when
installed; and
[0014] FIG. 3 is a detailed view of the means for detecting the
cable tension of the quick-action tensioning device.
DESCRIPTION OF EMBODIMENT(S) OF THE INVENTION
[0015] While one or more embodiments of the invention are described
herein, the invention is not intended to be limited thereby.
Instead, there are equivalents and variations, as should be
appreciated by those skilled in the art that are also intended to
fall within the scope of the invention.
[0016] A quick-action tensioning device 1 for a cable control
switch comprises a holding element 2 to which a cable 3 can be
secured. For this purpose, the cable 3 is tensioned between a plate
4 and the body of the holding element 2, wherein the plate 4 can be
secured via a screw 5, thus clamping deflection of the cable 3
between the plate 4 and holding element 2.
[0017] Also provided, for fine adjustment of the tension of the
cable 3, is a knurled nut 10 which can be used to vary the distance
between the holding element 2 and a housing 8. The knurled nut is,
in this case, connected to a shank 9 via a thread. An optical
display 11 for the cable tension can be provided on the housing 8,
a marking being attached to a viewing window 12. The mark can be
displayed via a movable strip 13 to indicate whether the tension of
the cable is too high or too low.
[0018] Also provided is a housing 14 of a cable control switch. The
housing 14 has a triggering button 15, so that switching can take
place in the event of the tension of the cable 3 deviating from a
range of setpoints. Switching also can take place manually by
pressing the switch 15.
[0019] FIG. 2 shows the quick-action tensioning device when
installed. The cable 3 is guided via a plurality of eyelets 6 which
are each secured to a holder 7, wherein the cable 3 can, for
example, be tensioned around a machine. Provided at the end of the
cable 3 is a further quick-action tensioning device with a holding
element 2 having a knurled nut 10 for fine adjustment and also an
eyelet 16 which is coupled to a pulling element 17. The pulling
element 17 is connected via a spring 18 to a holder 19 which is
secured to a fixed attachment or a wall 20.
[0020] Provided in the housing 14 of the cable control switch is an
electronic device for detecting the tension, by means of which
device a signal can be generated to a controller 22 via a line 21
if the tension deviates from a range of setpoints. If, for example,
the tension of the cable 3 is increased as a result of an accident,
the corresponding machine is switched off via the cable control
switch 14. It can, however, also occur that during operation, as a
result of an extension of the cable 3 and other factors, the cable
tension drops but there is no emergency situation. Then, if the
cable tension drops out of a range of setpoints, a signal can be
issued to the controller 22 in good time via the electronic means,
indicating that the cable tension should be adjusted. For this
purpose, the controller 22 can be connected to a display device
23.
[0021] In addition, the controller 22 can be coupled to a
temperature sensor, thus allowing a change in length as a result of
deviations in temperature to be detected, wherein the range of
setpoints can then be adjusted accordingly on the controller as a
function of the temperature.
[0022] FIG. 3 shows in detail the device for detecting the cable
tension. A bracing 30 is mounted so as to be able to pivot about an
axis 31 and coupled to the cable 3 via various components, so that
the bracing 30 is moved in the event of a change in the cable
tension. In the tensioned state, an optical gap is interrupted by
the bracing 30. If the tension of the cable 3 changes, the optical
gap is cleared and a signal is issued to the controller 22. In this
case, an optical sensor 33 is provided on a holding device 32. A
plurality of gaps in the form of recesses, windows or the like can
also be provided in the bracing 30, wherein the direction of
triggering can in addition also be seen. Furthermore, corresponding
markings can also be used to detect the extent of the movement of
the bracing.
[0023] With a second bracing, a redundant system can also be
constructed with a separate gap.
[0024] In the illustrated exemplary embodiment, the optical
detection system is shown merely schematically. It is of course
also possible to provide other optical or magnetic sensors for
detecting the cable tension.
* * * * *