The present invention is directed to a cable tensioner and method of maintaining tension for a cable conveyor system.
Conveyor systems, such as cable conveyor systems, are commonly used to move materials, such as articles in automated manufacturing facilities to desired locations, which articles being manipulated by dedicated machinery onto pallets. Cable conveyor systems often utilize endless belts or interconnected belt members that are drivingly moved and supported, such as by rollers or a track along a path. A drive unit, such as a motor rotatably drives a drive pulley that drivingly carries a cable positioned beneath the product being conveyed. An idler or idler pulley, sometimes referred to as a take-up idler, maintains the cable in tension for proper operation of the conveyor system. In some cases there is a drive unit with take-up included for longer cable runs (e.g., 1,000 ft) used along with a take-up idler, both work together to maintain the proper tension in the cable run.
As a result of wear or cable elongation or other reasons, cable tension can be adversely affected. If proper tension is not maintained, slippage between the cable, drive pulley and/or belt may occur, potentially resulting in surging, jamming, and extreme wear on the cable, belt and/or track, or the cable may twist into the drive unit and cause damage, or at the least a noticeable decrease or complete loss of performance may occur. In the case of cable conveyors, poor take-up may cause drive unit damage or may permit the cable to slip off or otherwise become disengaged from the cable conveyor system.
Unfortunately, it is generally not possible to easily determine whether the cable tension is proper, especially when the cable conveyor system is operating.
There is a need in the art for a tensioner and method for maintaining a cable conveyor system.
In an embodiment, a cable tensioner includes a spring having a first position, the spring operatively connectable to a cable conveyor system; and visually apparent indicia corresponding to a force applied to a cable of the cable conveyor system as a result of a spring deflection away from the first position, the force placing the cable of the cable conveyor system in tension.
In a further embodiment, a method of maintaining a cable conveyor system includes operatively connecting a spring to a cable conveyor system, installing a visually apparent indicia, and monitoring the indicia.
Other features and advantages of the present invention will be apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.
Referring to
Returning to
As further shown in
In one embodiment, the highly reflective surface of band 32 is visually apparent at at least 40 feet with an illumination source of 50 lumens such as emitted from a flashlight of a conventional cellular telephone, as the tensioner may be positioned in a non-illuminated area of a facility. In one embodiment, band 32 may include a self-contained illumination source, such as embedded flashlight or flashlight secured to band or tubular enclosure. In one arrangement, re-tensioning of the cable tensioner may be needed if the portion of the band protruding past end 24 away from indicia window 16 is visually apparent, such as shown in
When cable tensioner 12 is assembled, as shown in
Shim(s) 44 permit enhanced calibration of the tensioner. That is, manufacturing tolerances for springs may be +/−0.13 inch or more. Use of shims can reduce the error to +/−0.01 inch which translates into a reading error correction at the use point from plus/minus 20% to plus/minus 1.6%, which allows for more meaningful target set points for the technician setting and reading this device.
Referring to
In one embodiment, device 70 may be operably connected to a drive unit 98 of the cable conveyor system for discontinuing operation of the cable conveyor system in response to the cable tension being less than a first predetermined value or greater than a second predetermined value or in response to a predetermined change in cable tension within a predetermined time. That is, for example, if the cable conveyor system optimally operates with a cable tension between 5 and 10 pounds of cable tension, these differences in cable tension possibly being due to seasonal temperature differences, the device 70 could be set to discontinue operation, such as by deactivating drive unit 98 if the cable tension is less than 5 pounds or greater than 10 pounds, or drive unit 98 could be deactivated if a change in cable tension or more than several pounds within a few seconds or minutes, which is a possible indicator of a malfunction or failure of a cable system component. By virtue of these features, inadvertent damage to the cable conveyor system may be prevented. In one embodiment, device 70 is operably connected to spring 30 for selectively varying the spring deflection relative to an uncompressed position for maintaining the cable tension at at least a first predetermined value associated with proper operation of the cable conveyor system. In one embodiment, device 70 is operably connected to a drive unit 98 that is adapted to change the spring deflection to maintain the cable tension between a first predetermined value and a second predetermined value.
As further shown in
The cable tensioner of the present disclosure is configured to fit within the operating envelope of existing tensioning springs and idlers of conventional cable conveyor systems, and therefore may be seamlessly retrofitted in such systems.
Irrespective the form of indicia utilized (e.g., reflective band 32 visible in indicia window 16 or display 100) or the indicia monitoring arrangement utilized in step 120, i.e., manual adjustment (e.g., via jam nuts) or automated adjustment (e.g., via drive unit), the indicia corresponds to an amount of cable tension of the cable conveyor system. In step 122, which is a monitoring branch of a process loop from step 120, the amount of cable tension is compared to an acceptable range of cable tension associated with proper operation of the conveyor system. If the amount of cable tension is within this acceptable range (i.e., is “correct”), no action is taken, and the process loop returns to step 120 for subsequent monitoring of the indicia (cable tension). If the cable tension falls outside this acceptable range (i.e., is “not correct”), then in step 124, the amount of cable tension is compared to a maximum acceptable cable tension value. If the cable tension is greater than the maximum acceptable cable tension value, the cable is “too tight”, and the take-up or take-up drive is loosened in step 126 and the process loop returns to step 120 for subsequent monitoring of the indicia (cable tension). If the cable tension is not greater than the maximum acceptable cable tension value in step 124, then the cable tension is too low, and the take-up or take-up drive is tightened in step 128 and the process loop returns to step 120 for subsequent monitoring of the indicia (cable tension).
While the invention has been described with reference to one or more embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. In addition, all numerical values identified in the detailed description shall be interpreted as though the precise and approximate values are both expressly identified.
Number | Name | Date | Kind |
---|---|---|---|
4253343 | Black | Mar 1981 | A |
4539001 | Okabe | Sep 1985 | A |
4995506 | Langenbacher | Feb 1991 | A |
5030173 | Bryant | Jul 1991 | A |
5615775 | Barbaret | Apr 1997 | A |
5788697 | Kilpela | Aug 1998 | A |
6073755 | Hilliard | Jun 2000 | A |
6336550 | Muntener | Jan 2002 | B1 |
6439377 | Ellis | Aug 2002 | B1 |
6585109 | Beyer | Jul 2003 | B1 |
6594460 | Williams | Jul 2003 | B1 |
7374072 | Irwin | May 2008 | B2 |
7448491 | Tippery | Nov 2008 | B1 |
7520378 | Hansen | Apr 2009 | B2 |
7553248 | Busboom | Jun 2009 | B2 |
9033136 | Hesketh | May 2015 | B2 |
9809389 | Pauli | Nov 2017 | B2 |
10071862 | Barry | Sep 2018 | B1 |
Number | Date | Country | |
---|---|---|---|
20190256295 A1 | Aug 2019 | US |