TORQUE ARM ASSEMBLY FOR A BACKSTOPPING CLUTCH
A torque arm assembly for a backstopping clutch is provided that enables load sharing among multiple torque arm assemblies, controlled release of load on the torque arm assembly and load sensing. The torque arm assembly includes a head member that is connected to an outer race of a backstopping clutch and defines a pair of attachment points. One end of an arm member is pivotally connected to one attachment point of the head member while the other end of the arm member is connected to a stationary structure. A strut extends between the other attachment point of the head member and the arm member. Upon backstopping action by the clutch, the head member rotates slightly against the force of the strut allowing other torque arm assemblies to receive a portion of the system load. Movement of a strut seat then allows controlled release of the load tension.
1. Field of the Invention
This invention relates to torque arm assemblies for backstopping clutches and, more particularly, to a torque arm assembly that facilitates load sharing among multiple backstop assemblies within a larger system.
2. Disclosure of Related Art
In many motor driven systems, it is desirable to prevent or limit movement of system components in one direction. For example, and with reference to
Backstopping clutches 16 are typically used to prevent reverse rotation of rotating system components. Referring to
Referring again to
Conventional torque arm assemblies such as assembly 32 have several disadvantages. The rigid nature of the torque arm assembly 32 results in instantaneous engagement of the outer and inner races 18, 24 of clutch 16 and therefore requires that clutch 16 be designed to absorb the maximum load on the conveyor 10. Accordingly, the clutches 16 are relatively expensive. This is particularly problematic in systems incorporating multiple motors 14 and clutches 16. In large conveyor systems or in other applications, multiple backstopping clutches 16 may be disposed on a single shaft 20 and/or clutches may be required for multiple motor driven shafts 20. There is also no mechanism for indicating the load on clutch 16 and no mechanism for releasing load or tension on clutch 16. Some torque arm assemblies have been devised to enable load sharing among multiple clutches in large systems. Referring to
The inventors herein have recognized a need for a torque arm assembly for a backstopping clutch that will minimize and/or eliminate one or more of the above-identified deficiencies.
SUMMARY OF THE INVENTIONThe present invention provides an improved torque arm assembly for a backstopping clutch.
A torque arm assembly in accordance with one embodiment of the present invention includes a head member configured for connection to an outer race of the backstopping clutch, the head member defining first and second spaced attachment points. The assembly further includes an arm member configured for connection to a stationary structure proximate a first end of the arm member and pivotally connected to the first attachment point of the head member proximate a second end of the arm member. The assembly further includes a strut coupled at a first end to the second attachment point of the head member and at a second end to the arm member. In accordance with another embodiment of the invention, the assembly may include a sensor or a graduated load indicator scale disposed between the head member and arm member and configured to indicate the distance between the head member and arm member and, therefore, the load on the clutch and torque arm assembly. In accordance with my another embodiment of the invention, a strut seat on the arm member is adjustable along an axis of the strut to enable a controlled release of the load or tension on the clutch and torque arm assembly. In yet another embodiment of the invention, a damper is connected at one end to the head member and at a second end to the arm member and is used with the strut to tune the assembly for controlled reaction of system forces.
A torque arm assembly in accordance with the present invention represents a significant improvement relative to conventional assemblies. The assembly enables a controlled, limited motion of the outer race of the clutch thereby delaying clutch engagement and enabling load sharing among clutches and torque arm assemblies in large systems. Further, the assembly enables load sharing without requiring expensive modifications to existing systems. The assembly also provides an indication of load on each assembly and enables a controlled release of load or tension on the clutch and assembly. The assembly further enables tuning of the assembly to control reaction to forces in the system in which the assembly is employed.
These and other advantages of this invention will become apparent to one skilled in the art from the following detailed description and the accompanying drawings illustrating features of this invention by way of example.
Referring now to the drawings wherein like reference numerals are used to identify identical components in the various views,
Head member 42 is provided to couple the outer race 24 of clutch 16 and the remaining components of assembly 40. Member includes first and second clutch attachment plates 50, 52 and an arm attachment plate 54. Although plates 50, 52, 54 are shown as separate elements in the illustrated drawing, it should be understood that plates 50, 52, 54 could be integrated to form a unitary structure.
Plates 50, 52 are coupled to opposite sides of outer race 24. Plates 50, 52 may include a plurality of aligned apertures 56 disposed in a circular pattern and configured to receive fasteners 58 extending through plates 50, 52 and outer race 24. Plates 50, 52 may be annular to provide clearance for driven shaft 20 and portions of clutch 16. Plates 50, 52 may be generally bell shaped and may define a space therebetween extending outwardly from clutch 16 and configured to receive plate 54 (as best shown in
Plate 54 is disposed between plates 50, 52 and is coupled to plates 50, 52 through fasteners 64. Referring to
Arm member 44 transmits the load on clutch 16 and assembly 40 to a stationary structure, such as structure 39 shown in
Referring again to
Nut assembly 80, fasteners 82 and strut seat 84 provide a means for releasing load or tension on clutch 16 and arm assembly 40. Referring now to
Referring again to
Referring to
Referring now to
A torque arm assembly 40 in accordance with the present invention represents a significant improvement relative to conventional assemblies. The assembly 40 enables load sharing among multiple assemblies 40 by allowing a limited, controlled reverse rotation of the outer race 24 of backstopping clutch 16 to thereby provide time for other clutches 16 and assemblies 40 to absorb a portion of the load. Moreover, load sharing is accomplished without the need for expensive modifications to the system support structure (e.g., support structure 39 of conveyor 10). The inventive assembly further enables a controlled release of load or tension on the clutch and assembly 40 by permitting movement of one seat 84 of the strut 46. The assembly further enables sensing of the load on the clutch 16 or assembly 40.
While the invention has been shown and described with reference to one or more particular embodiments thereof, it will be understood by those of skill in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
Claims
1. A torque arm assembly for a backstopping clutch, comprising:
- a head member configured for connection to an outer race of said backstopping clutch, said head member defining first and second spaced attachment points;
- an arm member configured for connection to a stationary structure proximate a first end of the arm member and pivotally connected to said first attachment point of said head member proximate a second end of said arm member; and,
- a strut coupled at a first end to said second attachment point of said head member and at a second end to said arm member.
2. The torque arm assembly of claim 1, further comprising a damper connected at one end to said head member and at a second end to said arm member.
3. The torque arm assembly of claim 2 wherein said damper is arranged substantially parallel to said strut.
4. The torque arm assembly of claim 1 further comprising a sensor configured to generate a signal indicative of a distance between said head member and said arm member.
5. The torque arm assembly of claim 4 wherein said sensor comprises a linear voltage displacement transducer.
6. The torque arm assembly of claim 1, further comprising a graduated load indicator scale disposed between said head member and said arm member.
7. The torque arm assembly of claim 6 wherein said strut comprises a spring and said scale is located on a shaft arranged coaxially with said spring.
8. The torque arm assembly of claim 6 wherein said scale is located in parallel to said strut.
9. The torque arm assembly of claim 1 wherein said arm member includes a strut seat against which said second end of said strut reacts, said strut seat adjustable along an axis of said strut.
10. The torque arm assembly of claim 1 wherein said second end of said strut is connected to said arm member intermediate said first and second ends of said arm member.
11. A backstopping clutch and torque arm assembly, comprising:
- a backstopping clutch comprising: an inner race configured for connection to a driven shaft; an outer race disposed radially outwardly of said inner race; and, a plurality of rollers disposed between said inner and outer races, said plurality of rollers configured to engage said outer race and inhibit rotation of said inner race and said driven shaft in a first rotational direction; and,
- a torque arm assembly, comprising: a head member configured for connection to said outer race of said backstopping clutch, said head member defining first and second spaced attachment points; an arm member configured for connection to a stationary structure proximate a first end of the arm member and pivotally connected to said first attachment point of said head member proximate a second end of said arm member; and, a strut coupled at a first end to said second attachment point of said head member and at a second end to said arm member.
12. The backstopping clutch and torque arm assembly of claim 11, further comprising a damper connected at one end to said head member and at a second end to said arm member.
13. The backstopping clutch and torque arm assembly of claim 12 wherein said damper is arranged substantially parallel to said strut.
14. The backstopping clutch and torque arm assembly of claim 11, further comprising a sensor configured to generate a signal indicative of a distance between said head member and said arm member.
15. The backstopping clutch and torque arm assembly of claim 14 wherein said sensor comprises a linear voltage displacement transducer.
16. The backstopping clutch and torque arm assembly of claim 11, further comprising a graduated load indicator scale disposed between said head member and said arm member.
17. The backstopping clutch and torque arm assembly of claim 16 wherein said strut comprises a spring and said scale is located on a shaft arranged coaxially with said spring.
18. The backstopping clutch and torque arm assembly of claim 16 wherein said scale is located in parallel to said strut.
19. The backstopping clutch and torque arm assembly of claim 11 wherein said arm member includes a strut seat against which said second end of said strut reacts, said damper seat adjustable along an axis of said strut.
20. The backstopping clutch and torque arm assembly of claim 11 wherein said second end of said strut is connected to said arm member intermediate said first and second ends of said arm member.
Type: Application
Filed: May 3, 2007
Publication Date: Nov 6, 2008
Inventor: David Pearson Stoltze (Brighton, MI)
Application Number: 11/743,894
International Classification: F16D 15/00 (20060101);