Motor control center units with multi-purpose shutter cams and related units

Patent metadata

Field	Value
Publication number	US-10211606-B2
Application number	US-201715786248-A
Country	US
Kind code	B2
Filing date	Oct 17, 2017
Priority date	Nov 29, 2016
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

Motor control centers have units or buckets with multi-purpose shutter cams that slide shutters right and left to controllably block access to a portal of an isolation lead screw that can extend and retract power connectors and that provides one or more safety interlock engagement features that prevent certain actions depending on the operating state of the buckets.

First claim

That which is claimed is:

1. A bucket, comprising:
a bucket housing with laterally spaced apart sidewalls and at least one front panel;
an operator handle residing in front of the at least one front panel and having an inwardly extending drive shaft;
a shutter cam attached to the drive shaft, wherein the shutter cam comprises a first cam segment with a first curvilinear outer perimeter and a second cam segment with a second curvilinear outer perimeter, and one of the first cam segment and the second cam segment resides behind another of the first cam segment and the second cam segment, in a front-to-back direction of the bucket housing; and
at least one shutter positioned between the first and second cam segments of the shutter cam, the at least one shutter comprising a primary body with a shutter portal, the at least one shutter further comprising first and second laterally spaced apart outwardly projecting members that reside at a level below the shutter portal,
wherein the first cam segment of the shutter cam engages the first outwardly projecting member to laterally slide the at least one shutter in a first direction to a position that misaligns the shutter portal with a socket of a lead screw in the bucket when the operator handle is in a first position,
wherein the first cam segment of the shutter cam engages the second outwardly projecting member to laterally slide the at least one shutter in a second direction opposite the first direction to a position that aligns the shutter portal with the socket of the leadscrew when the operator handle is in a second position, and
wherein the second cam segment provides at least one interlock engagement feature for releasably engaging at least one of a cabinet lock pin, a manual key lock or a door latch that prevents the operator handle from rotating.

2. The bucket of claim 1 , wherein the at least one shutter comprises a lateral extension with a downwardly extending planar vertically oriented segment residing above the drive shaft and positioned between the first and second cam segments of the shutter cam in the front-to-back direction and projecting in a direction towards the first cam segment, the downwardly extending planar vertically oriented segment comprising the first and second laterally spaced apart outwardly projecting members, and wherein the second cam segment resides behind the first cam segment in the front-to-back direction of the bucket housing.

3. The bucket of claim 1 , wherein the first and second cam segments are joined at a neck portion that has a channel that receives the drive shaft, and wherein in a planar view of the shutter cam, the first cam segment has a portion of the first curvilinear outer perimeter facing an adjacent longitudinally and laterally spaced apart curvilinear perimeter portion of the second curvilinear outer perimeter of the second cam segment.

4. The bucket of claim 1 , wherein the shutter cam is a three dimensional single monolithic member, and wherein the shutter cam further comprises a first forwardly projecting segment attached to the first cam segment and a second forwardly projecting segment attached to the second cam segment.

5. The bucket of claim 1 , wherein the first cam segment has a distance that is less than a maximal radius of the second cam segment, the radius measured from a centerline of the drive shaft.

6. The bucket of claim 1 , wherein in a planar view of the shutter cam, the second cam segment has a portion of the second curvilinear outer perimeter that is adjacent to a portion of the first curvilinear outer perimeter of the first cam segment with a curvilinear gap space between the adjacent portions of the first and second curvilinear outer perimeters of the first and second cam segments.

7. The bucket of claim 1 , wherein the shutter cam further comprises at least one of:
(i) a first forwardly projecting segment attached to the first cam segment and a second forwardly projecting segment attached to the second cam segment;
(ii) at least one lug access aperture to thereby allow access to a phase A, B or C lug screw in an OFF position associated with non-conduction; or
(iii) a planar rear surface with the second cam segment having an outer perimeter wall that is orthogonal to the planar rear surface and projects rearward a distance from the planar rear surface of the second cam segment.

8. The bucket of claim 1 , wherein the shutter cam further comprises a planar rear surface with the second cam segment having an outer perimeter wall that is orthogonal to the planar rear surface and projects rearward a distance from the planar rear surface of the second cam segment, and wherein the second cam segment has a portion of the second curvilinear outer perimeter that faces a curvilinear gap space that has a circumferential angular extent, measured from a center of the shaft, that is between 90-270 degrees.

9. The bucket of claim 1 , wherein the at least one of the cabinet lock pin, the manual key lock or the door latch includes the cabinet lock pin, and wherein the cabinet lock pin extends laterally and resides behind the shutter cam in the bucket housing, the laterally extending cabinet lock pin attached to an actuator rod that slidably moves the cabinet lock pin between engaged and disengaged positions, wherein the actuator rod extends forward toward the operator handle a length sufficient to engage a first portion of the second curvilinear outer perimeter of the second cam segment of the shutter cam as a first of the at least one interlock feature of the second cam segment and block the operator handle from rotating to an ON position as the first position when the cabinet lock pin is in the engaged position.

10. The bucket of claim 9 , wherein a different second portion of the second curvilinear outer perimeter of the second cam segment of the shutter cam resides adjacent the actuator rod when the actuator rod is in the engaged position as a second of the at least one interlock feature and blocks movement of the actuator rod when the operator handle is in the ON position as the first position to thereby prevent the cabinet lock pin from being moved to the disengaged position.

11. The bucket of claim 9 , wherein the second curvilinear outer perimeter of the second cam segment comprises a straight portion adjacent a curvilinear outer portion, and wherein the actuator rod extends over the straight portion as the first portion to engage the second cam segment of the shutter cam and block the handle from rotating to the ON position when the cabinet lock pin is in the engaged position.

12. The bucket of claim 1 , wherein the second cam segment of the shutter cam has a lower interior recessed space as a door interlock feature as the at least one interlock feature and that releasably engages a spring-loaded arm to thereby block the shutter cam from rotating from an OFF position to an ON position when a door of a cabinet is open, the door of the cabinet opens to permit access to the bucket.

13. The bucket of claim 1 , wherein the at least one of the cabinet lock pin, the manual key lock or the door latch includes the door latch, and wherein the door latch is attached to the shutter cam and controllably engages a cabinet door to prevent the cabinet door from opening if the operator handle is any position other than a RESET position, the cabinet door opens to permit access to the bucket.

14. The bucket of claim 1 , wherein the at least one of the cabinet lock pin, the manual key lock or the door latch includes the door latch, and wherein the door latch is attached to the first cam segment of the shutter cam and extends laterally outward from the shutt

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Kroushl Daniel Boyd
• Beard Alfred Gregory
• Yee Edgar

Classifications

• H05K5/023

  Handles; Grips · CPC title

• H02B11/24

  Shutters or guards · CPC title

• H01H9/22

  for interlocking between casing, cover, or protective shutter and mechanism for operating contacts {(explosion-proof cases H01H9/045; built-in fuses and interlocking mechanisms H01H9/104; by automatic release of circuit breakers H01H71/126)} · CPC title

• H01H71/56

  actuated by rotatable knob or wheel · CPC title

• H02B1/36 Primary

  with withdrawable units · CPC title