US2300563A - Grounding device - Google Patents

Description

Nov. 3, 1942. I

0. J. GAUB 2,3005563 GROUNDING DEVICE.

Filed Oct. 29, 1941 Patented Nov. 3, 1942 l uN Eo" STATE T v, OFFICE 1 GROUNDING DEVICE Otto J. Gaub, 01a Bridge, N. J. Application October 29, 1941, Serial No. 417,006 (01. 173-273) 3 Claims.

such materials. Manygrounding devices for this purpose are available but in practical use have demonstrated several serious defects which reduce their effectiveness and otherwise make them of doubtful utility. For example, in many such devices difliculty is experienced in attaching and removing the clamp and this fault appreciably retards production. operations. Contact surfaces on previously available devices are arranged so as-to make electrical contact on the inside of the container and thus become contaminated with the container contents, thereby reducing the effectiveness of the contact. Also, the contact surfaces on the conventional clamp are fixed points andthesepoints soon become dull due to the drag encountered in traveling over the edge of the container when the device is attached and removed and this also reduces the certainty of proper contact.

In the improved grounding device of the pres ent invention, these and other defects of previously available ground clamps are eliminated and its ready acceptance in the industry reflects the urgently needed advantages offered in the new device.

This invention has as an object the provision of an improved portable ground clamp which is simple in construction and which is readily attachable and removable. Another object is the provision of a ground clamp which provides contacts outside the container to be grounded. Another object is the provision of an improved ground clamp in which contact is made by means of a rotatable element having sharp edges, thus insuring more certain conduction of static charges. A further object is the provision of an improved ground clamp in which contact is made through a roller construction, thus affording long life for the contact element. A still further object is the provision of an improved ground clamp which hugs the side of the container due to the contact being below the center of the rim or edge. A still further clamp which is particularly adapted for use with I containers having a beaded ,top edge. Other objects will appear as the description of the invention proceeds.

These objects are accomplished by means of animprovedground clamp which comprises essentiall y a rigid. non-sparking metal member offset in opposite directions to provide a hook at one end and a hand grip at the other and a non-sparking spring pressed roller grip element afiixed to, the rigid member and nested within the hook. 1

In the accompanying drawing which illustrates the. preferred embodiment of my invention: I

, Figure 1 is a sectional side view of the improved device showing the specific arrangement of the various elements disposed in their proper position. 1

Figure 2 is a front .view of the device which illustrates the construction and position of the roller contact in relation to the supporting element- V I Figure 3, shows thedetail of the roller contact.

Fig. 4 is a sectional side View of the device illustrating its utility as a ground clamp for a container with a beaded top edge.

Referring specifically to the drawing: In Figure 1, the roller contact 1, the rotatable shaft of which .is enclosed .by,t he turned end 2 of the spring supporting element 3 attached to the rigid metal member t by screws 5, is nested within thehook 6. The spring supporting element 3 preferably consists of two fiat flexible or semi-rigid members adjacently disposed. The hook 6, which comprisesv an essential element of the rigid member l, is-oifset in opposite direction to the hand grip I and preferably consists of a ghard portion 8, a stop 9 and a lip I0. The lip I0 also preferably terminates at a point directly opposite the center of the rotatable roller contact shaft. The lug II is attached to the rigid element part of the device by the screws l2 and carries the ground wire I3.

As previously stated, Figure 2 represents a front view of the device which illustrates the disposition of the knife edge roller contact in relation to the spring and contact holder. The identifying numerals correspond in their meaning tothose referred to above for Figure 1.

Figure 3 shows the detail construction of the knife edge roller contact comprising two knife edge members fixed at opposite ends of a rotatobject is the provision of an improved ground able shaft.

In Figure 4, the device is shown properly the clamp is difficult and such arrangement also causes undue flexing in the spring member. If the hook terminus is above the axis of the shaft of the roller contact, there is a tendency to force the clamp away from the container side and thus become loose or completely detached. l

The device is also preferably completely fabricated from a non-sparking metal such as beryllium, copper or bronze. Phosphor bronze is satisfactory for constructing the device and has been found to be particularly adapted for the roller contact element and the spring supporting element.

In using the device, it is merely gripped by the hand grip l and pulled down. over the rim of a container so that the hook terminus or lip l0 engages the inside of the container. At the same time the knife edge roller contacts in traveling over the edge of the outside of the container cut through any coating or other non-conducting material on the outside surface of the container, thus insuring positive contact with the metal of the container, To remove the device it is only necessary to lift up with slight pressure on the hand grip.

The improved ground clamp is useful generally for grounding static electricity, particularly for grounding metal containers which contain inflammable materials. It is especially adapted for containers which have a beaded top edge.

The advantages of the new grounding device are several and commercially important as refiected by the immediate and rapidly growing acceptance in the industry. The device is simple in construction and in use is more readily attached and removed than in such devices heretofore available. Contacts are outside the con tainer rather than on the inside as provided by older ground clamps and this is important in containers for paint materials where contamination of contact points and resultant uncertain contact is obviated. The device provides sharp knife edge rotatable contacts, thus insuring more certain contact and conduction of static charges. The roller construction of the knife edge contacts affords long life for the contact element. The preferred embodiment of the invention which provides contact below the center of the rim or edge of the container causes the device to hug the side of the container and prevents accidental loosening or dislodgement of the device. The new clamp is of particular advantage for grounding containers which have a beaded top edge, a type of container for which grounding devices heretofore available have not been satisfactory,

It is apparent that many widely different embodiments of the invention may be made without departing from the spirit and scope thereof; and, therefore, it is not intended to be limited except as indicated in the appended claims.

'I claim:

1. A portable non-sparking metal ground clamp, particularly adapted for use with containers having a beaded top edge, comprising a rigid metal member with a hook at one end and a hand grip ofiset in opposite direction at the other end and a springpressed roller grip element afiixed to the rigid member and nested within the hook, said roller grip element consisting of a rotatable shaft carrying knife edge circular contact members at each end of the shaft and mounted at the free end of the spring element.

2. A portable non-sparking metal ground clamp, particularly adapted for use with containers having a beaded top edge, comprising a rigid metal member with a hook at one end and a hand grip offset in opposite direction at the other end and a. spring pressed roller grip element afiixed to the rigid member and nested withinthe hook, said roller grip element consisting of a rotatable shaft carrying knife edge circular contact members at each end of the shaft and mounted at the free end of the said spring element so that the axis of the rotatable shaft is disposed directly opposite the end of the hook.

3. A portable non-sparking metal ground clamp, particularly adapted for use with containers having a beaded top edge, comprising a rigid metal member with a hook at one end and a hand grip offset in opposite direction at the other end and a phosphor bronze spring pressed roller grip element afiixed to the rigid member and nested within the hook, said roller grip element consisting of a rotatable shaft carrying knife edge circular contact members at each end of the shaft and mounted at the free end of the spring element.

OTTO J. GAUB.

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