Universal ground clamp

Claim 2

A universal ground clamp for independent attachment to and release from grounding electrodes and ground wires of different size comprising a strap sub-assembly for electrically engaging the grounding electrode and a bolt sub-assembly mounted on the strap sub-assembly and providing electrical contact with the ground wire of an electrical system, said strap sub-assembly including an elongated flexible strap and a generally U-shaped contact bracket securely and retainably mounting one end of said strap and having arcuate contact surfaces for providing electrical contact with the grounding electrode, the strap portion adjacent said contact bracket extending tagentially of said arcuate contact surfaces, said bolt sub-assembly consisting essentially of a single bolt having a fixed land with a platen intersecting the axis of the bolt at an intermediate position along its length, said platen having an elongated bearing surface facing a first end of the bolt and being convexly bowed in its transverse dimension, a wire-receiving aperture intermediate said bowed surface and a second end of said bolt opposite said first end, said wire-receiving aperture having an axis extending generally parallel to the axis of said convexly bowed surface for receiving the ground wire of an electrical system, a clamping cap mounted on said second bolt end and moveable toward said platen for clampably engaging a ground wire positioned within said wire-receiving aperture and retaining means on said bolt for movement toward said convexly bowed platen surface, said bolt sub-assembly being mounted on said strap sub-assembly upon encirclement of the grounding electrode by the elongated strap whereby the contact surfaces of the strap remote from the bracket conformably engages the convexly bowed bearing surface.

Claim 3

The clamp of claim 1 wherein said platen is generally rectangular and said land includes a sleevelike boss with said wire-receiving aperture extending therethrough.

Claim 4

The clamp of claim 1 wherein said platen is generally rectangular and the axis of said wire-receiving aperture extends along the longitudinal dimension of said platen.

Claim 5

The clamp of claim 1 wherein said retaining means includes first retaining means on said first bolt end independently operable to draw said platen portion toward said bracket when securing the clamp to a grounding electrode and second retaining means on said second bolt end independently operable for urging said clamping cap into clamping engagement with a ground wire within said wire-receiving aperture.

Claim 6

The clamp of claim 1 wherein said contact bracket has a planar base portion and a pair of upstanding side portions carrying said contact surfaces, said base portion securely and retainably mounting one end of said strap such that said strap extends forwardly therefrom tagentially of said contact surfaces.

Claim 7

The clamp of claim 5 wherein said side portions each have an upstanding forward edge with a radius of curvature sufficient to provide full surface contact with a grounding electrode of cylindrical design and with opposite ends of said concave edges being convex to provide multiple point contact with relatively larger diameter grounding electrodes.

Claim 8

The clamp of claim 1 wherein said bracket includes planar base portion retainably mounting one end of said strap whereby said strap extends forwardly therefrom, said base portion having an aperture therein for mounting said bolt sub-assembly.

Claim 9

The clamp of claim 7 wherein said first bolt end extends through the aperture in the bracket base portion and said retaining means includes means operable to draw said platen toward said bracket when securing the clamp to the grounding electrode.

Claim 10

The clamp of claim 1 wherein said elongated strap is of flexible metal and has a plurality of strap apertures spaced along the length thereof, said first bolt end extending through both a strap aperture in said remote strap portion and said bracket, said retaining means including means operable to draw said platen toward said bracket when securing the clamp to the grounding electrode.

Claim 11

The clamp of claim 1 wherein said platen is generally rectangular and said land includes a cylindrical sleeve-like boss coaxial with said bolt, said wire-receiving aperture extending through both the boss and the bolt with its axis extending along the longitudinal dimension of the rectangular platen.

Claim 12

The clamp of claim 1 wherein said contact bracket has a planar base portion and a pair of upstanding side portions, said base portion securely and retainably mounting one end of said strap such that said strap extends forwardly therefrom, said base portion having an aperture therein for mounting said bolt sub-assembly, said side portions each having a concave forward edge with a radius of curvature sufficient to provide full surface contact with a grounding electrode of cylindrical design and with opposite ends of said concave edges being convex to provide multiple point contact with relatively larger diameter grounding electrodes, said first bolt end extending through the aperture in the bracket base portion, said retaining means including means operable to draw said platen toward said bracket when securing the clamp to the grounding electrode.

Claim 13

A universal ground clamp for independent attachment to and release from grounding electrodes and ground wires of different size comprising a strap sub-assembly for encircling and electrically engaging the grounding electrode and a bolt sub-assembly mounted on the strap sub-assembly and providing electrical contact with the ground wire of an electrical system, said strap sub-assembly including an elongated flexible metal strap having a plurality of strap apertures spaced along the length thereof and a generally U-shaped contact bracket having a planar base portion and a pair of upstanding side portions, said base portion securely and retainably mounting one end of said strap such that said strap extends forwardly therefrom, said base portion having an aperture therein for mounting said bolt sub-assembly, said side portions each having a concave forward edge with a radius of curvature sufficient to provide full surface contact with a grounding electrode of cylindrical design and with opposite ends of said concave edges being convex to provide multiple point contact with relatively larger diameter grounding electrodes, said strap adjacent said contact bracket extending tagentially of the concave forward edges of said side portions, said bolt sub-assembly consisting essentially of a single bolt having a generally rectangular fixed land with a platen intersecting the axis of the bolt at an intermediate position along its length, said platen having an elongated bearing surface facing a first end of the bolt and being convexly bowed in its transverse dimension, said bolt having a wire-receiving aperture intermediate said bowed surface and a second end of said bolt opposite said first end, said wire-receiving aperture having an axis extending along the longitudinal dimension of the platen bearing surface and parallel to the axis of the grounding electrode for receiving the ground wire of an electrical system, a clamping cap mounted on said second bolt end and moveable toward said platen for clampably engaging said ground wire positioned within said wire-receiving aperture and retaining means on said bolt for movement toward said convexly bowed platen surface, said bolt sub-assembly being mounted on said strap sub-assembly whereby upon encirclement of the grounding electrode by the elongated strap the upstanding side portions of the bracket engage the grounding electrode and a portion of the strap remote from the bracket conformably engages the convexly bowed platen surface, said first bolt end extending through both a strap aperture in said remote strap portion and the aperture in the bracket base portion.

Claim 14

A universal ground clamp for independent attachment to and release from grounding electrodes and ground wires of different size comprising a strap sub-assembly for encircling and electrically engaging the grounding electrode and a bolt sub-assembly mounted on the strap sub-assembly and providing electrical contact with the ground wire of an electrical system, said strap sub-assembly including an elongated flexible metal strap having a plurality of strap apertures spaced along the length thereof and a generally U-shaped contact bracket having a planar base portion and a pair of upstanding side portions, said base portion securely and retainably mounting one end of said strap such that said strap extends forwardly therefrom, said base portion having an aperture therein for mounting said bolt sub-assembly, said side portions each having a concave forward edge with a radius of curvature sufficient to provide full surface contact with a grounding electrode of cylindrical design and with opposite ends of said concave edges being convex to provide multiple point contact with relatively larger diameter grounding electrodes, said strap adjacent said contact bracket extending tagentially of the concave forward edges of said side portions, said bolt sub-assembly consisting essentially of a single bolt having a generally rectangular fixed land with a platen intersecting the axis of the bolt at an intermediate position along its length, said platen having an elongated bearing surface facing a first end of the bolt and being convexly bowed in its transverse dimension, said bolt having a wire-receiving aperture intermediate said bowed surface and a second end of said bolt opposite said first end, said wire-receiving aperture having an axis extending along the longitudinal dimension of the platen bearing surface and parallel to the axis of the grounding electrode for receiving the ground wire of an electrical system, a clamping cap mounted on said second bolt end and moveable toward said platen for clampably engaging said ground wire positioned within said wire-receiving aperture and retaining means on said bolt for movement toward said convexly bowed platen surface, said bolt sub-assembly being mounted on said strap sub-assembly whereby upon encirclement of the grounding electrode by the elongated strap the upstanding side portions of the bracket engage the grounding electrode and a portion of the strap remote from the bracket conformably engages the convexly bowed platen surface, said first bolt end extending through both a strap aperture in said remote strap portion and the aperture in the bracket base portion.

Claim 15

The conduit of claim 12 wherein said land includes a cylindrical sleeve-like boss coaxial with said bolt, said wire-receiving aperture extending through both the boss and the bolt for receiving the ground wire of an electrical system.

Claim 16

The clamp of claim 12 wherein said retaining means includes first retaining means on said first bolt end independently operable to draw said platen toward said bracket when securing the clamp to the grounding electrode and second retaining means on said second bolt end independently operable for urging said clamping cap into clamping engagement with a ground wire positioned within said wire-receiving aperture.

Claim 17

A universal ground clamp for attachment to a grounding electrode and ground wire, comprising elongated strap means having an elongated, flat strap adapted to be wrapped about a grounding electrode to electrically connect the strap means to the electrode, said strap means, including the flat strap, having a plurality of longitudinally spaced apertures therealong to present a pair of generally opposed apertures in opposed segments of said strap means, including at least one segment of the flat strap, when the flat strap is wrapped about a grounding electrode, and a clamping fastener sub-assembly comprising an elongated threaded stud portion adapted to be received within a said pair of generally opposed apertures of the strap means with the flat strap so wrapped about a grounding electrode, and a pair of longitudinally spaced clamping head means on the stud portion having opposed inner faces for engaging said opposed segments of the strap means to claim the strap means to a grounding electrode, at least one of the clamping head means having at least a portion thereof threadably mounted on the threaded stud portion to selectively vary the distance between the clamping head means by relative rotation of the stud portion and said one clamping head means, thereby to selectively tighten and loosen the fastener sub-assembly, at least the other clamping head means having a rigid shoe portion with a said inner face with a convex, arcuate shape for engaging said one segment of the flat strap and forming said one segment into a conforming arcuate shape as the fastener sub-assembly is tightened to clamp the strap means to a grounding electrode, said convex, arcuate inner face of said shoe portion having a continuous convex curvature which extends in the direction of the flat strap, toward the grounding electrode when the flat strap is wrapped thereabout, from at least the centerline of said elongated stud portion, so that said one segment of the flat strap engaged by said inner face of said shoe portion is engaged along said continuous arcuate curvature of said shoe portion from at least approximately said centerline to minimize localized variation in stress in said strap segment, said other clamping head means having a transverse opening for receiving a ground wire and ground wire clamping means for clamping a ground wire within said transverse opening.

Claim 18

A universal ground clamp according to claim 15 wherein said shoe portion of said other clamping head means is fixed to the stud portion.

Claim 19

A universal ground clamp according to claim 15 wherein said ground wire clamping means provides for clamping a ground wire within said transverse opening after the fastener assembly is tightened to clamp the strap means to a grounding electrode.

Claim 20

A universal ground clamp according to claim 15 wherein said ground wire clamping means provides for clamping a ground wire within said transverse opening separately from said relative rotation of the stud portion and said one clamping head means.

Claim 21

In a ground clamp having elongated strap means with an elongated flat strap adapted to be wrapped about a grounding electrode to electrically connect the strap means to the electrode, said strap means, including the flat strap, having a plurality of longitudinally spaced apertures therealong to present a pair of generally opposed apertures in opposed segments of said strap means, including at least one segment of the flat strap, when the flat strap is wrapped about a grounding electrode, and a clamping fastener sub-assembly comprising an elongated threaded stud portion adapted to be received within a said pair of generally opposed apertures of the strap means with the flat strap so wrapped about a grounding electrode, and a pair of longitudinally spaced clamping head means on the stud portion having opposed inner faces for engaging said opposed segments of said strap means to clamp the strap means to a grounding electrode, at least one of the clamping head means being threadably mounted on the threaded stud portion to selectively vary the distance between the clamping head means, by relative rotation of the stud portion and said one clamping head means thereby to selectively tighten and loosen the fastener sub-assembly, the improvement wherein at least one of the clamping head means has a rigid shoe portion with a said inner face with a convex, arcuate shape for engaging said one segment of the flat strap and forming said one segment into a conforming arcuate shape as the fastener sub-assembly is tightened to clamp the strap means to a grounding electrode, said convex, arcuate inner face of said shoe portion having a continuous convex curvature which extends in the direction of the flat strap, toward the grounding electrode when the flat strap is wrapped thereabout, from at least the centerline of said elongated stud portion, so that said one segment of the flat strap engaged by said inner face of said shoe portion is engaged along said continuous arcuate curvature of said shoe portion from at least approximately said centerline to minimize localized variation in stress in said strap segment.

Claim 22

In a ground clamp having elongated strap means with an elongated flat strap adapted to be wrapped about a grounding electrode to electrically connect the strap means to the electrode, said strap means, including the flat strap, having a plurality of longitudinally spaced apertures therealong to present a pair of generally opposed apertures in opposed segments of said strap means, including at least one segment of the flat strap, when the flat strap is wrapped about a grounding electrode, and a clamping fastener sub-assembly comprising an elongated threaded stud portion adapted to be received within a said pair of generally opposed apertures of the strap means with the flat strap so wrapped about a grounding electrode, and a pair of longitudinally spaced clamping head means on the stud portion having opposed inner faces for engaging said opposed segments of said strap means to clamp the strap means to a grounding electrode, at least one of the clamping head means being threadably mounted on the threaded stud portion to selectively vary the distance between the clamping head means, by relative rotation of the stud portion and said one clamping head means thereby to selectively tighten and loosen the fastener sub-assembly, the improvement wherein at least one of the clamping head means has a rigid shoe portion with a said inner face with a convex, arcuate shape for engaging said one segment of the flat strap and forming said one segment into a conforming arcuate shape as the fastener sub-assembly is tightened to clamp the strap means to a grounding electrode, said convex, arcuate inner face of said shoe portion having a continuous convex curvature which extends in the direction of the flat strap, toward the grounding electrode when the flat strap is wrapped thereabout, from at least the centerline of said elongated stud portion, so that said one segment of the flat strap engaged by said inner face of said shoe portion is engaged along said continuous arcuate curvature of said shoe portion from at least approximately said centerline to minimize localized variation in stress in said strap segment.

Claim 23

In a ground clamp having elongated strap means with an elongated flat strap adapted to be wrapped about a grounding electrode to electrically connect the strap means to the electrode, said strap means, including the flat strap, having a plurality of longitudinally spaced apertures therealong to present a pair of generally opposed apertures in opposed segments of said strap means, including at least one segment of the flat strap, when the flat strap is wrapped about a grounding electrode, and a clamping fastener sub-assembly comprising an elongated stud portion adapted to be received within a said pair of generally opposed apertures of the strap means with the flat strap so wrapped about a grounding electrode, and a pair of longitudinally spaced clamping head means on the stud portion having opposed inner faces for engaging said opposed segments of said strap means to clamp the strap means to a grounding electrode, at least one of the clamping head means being mounted on the stud portion to selectively vary the distance between the clamping head means, thereby to selectively tighten and loosen the fastener sub-assembly, the improvement wherein at least one of the clamping head means has a rigid shoe portion with a said inner face with a convex, arcuate shape for engagement with said one segment of the flat strap to form said one segment into a conforming arcuate shape as the fastener sub-assembly is tightened to clamp the strap means to a grounding electrode, said convex, arcuate inner face of said shoe portion having a continuous convex curvature which extends in the direction of the flat strap and which is generally symmetrical about the centerline of said elongated stud portion so that said one segment of the flat strap engaged by said inner face of said shoe portion is engaged along said continuous arcuate curvature of said shoe portion from at least approximately said centerline to minimize localized variation in stress in said strap segment.

Claim 24

In a ground clamp having elongated strap means with an elongated flat strap adapted to be wrapped about a grounding electrode to electrically connect the strap means to the electrode, said strap means, including the flat strap, having a plurality of longitudinally spaced apertures therealong to present a pair of generally opposed apertures in opposed segments of said strap means, including at least one segment of the flat strap, when the flat strap is wrapped about a grounding electrode, and a clamping fastener sub-assembly comprising an elongated stud portion adapted to be received within a said pair of generally opposed apertures of the strap means with the flat strap so wrapped about a grounding electrode, and a pair of longitudinally spaced clamping head means on the stud portion having opposed inner faces for engaging said opposed segments of said strap means to clamp the strap means to a grounding electrode, at least one of the clamping head means being mounted on the stud portion to selectively vary the distance between the clamping head means, thereby to selectively tighten and loosen the fastener sub-assembly, the improvement wherein at least one of the clamping head means has a rigid shoe portion with a said inner face with a convex, arcuate shape for engagement with said one segment of the flat strap to form said one segment into a conforming arcuate shape as the fastener sub-assembly is tightened to clamp the strap means to a grounding electrode, said convex, arcuate inner face of said shoe portion having a continuous convex curvature which extends in the direction of the flat strap and which is generally symmetrical about the centerline of said elongated stud portion so that said one segment of the flat strap engaged by said inner face of said shoe portion is engaged along said continuous arcuate curvature of said shoe portion from at least approximately said centerline to minimize localized variation in stress in said strap segment.