US2785258A - Test handle - Google Patents

Description

R. A. HAIGH TEST HANDLE March 12, 1957 I5 Sheets-Sheet 1 Filed Dec. 16, 1953 INVENTOR i/l #az'yfi.

March 12, 1957 R. A. HAIGH 2,785,258

TEST HANDLE Filed Dec. 16, 1953 s Shets-Sheet 2 INVENTOR I RA flaz yfi.

' i BY ATTo EY R. A. HAIGH TEST HANDLE March 12, 1957 3 Sheets-Sheet 5 Filed Dec. 16, 1953 United States Patent O 43 253 TEST HANDLE Ru n Hais was, APP iQafi n D cembe 26 5 e a No 398,492

' 7 9 Clai s- (or. 20.0-15.1)

This invention relates to a test handle structure for ground test boxes. I

Ground test" boxes now in conventional use embody a wheel supported housing within which are various electric devices including a transtormer and selector.

The housing is providedwith an electric plug-in cable and a pair of outlet cables, each of which is provided with a terminal handle by which contact is made with the'pa'rticular device to be tested.

Th'e'outle't cables are of substantial length and the handles arepermanently united with the cables.

The handles necessarily embody major portions which areof insulating" material and accordingly do not have the capacity to withstand substantial impact without breakage thereof.

Thereferred to ground test boxes are used in many places wliere the handles, are subject to substantial impact even under the usual care by an operator. On the other hand, such handles are carelessly dropped or otherwise roughly handled with the result that some are H broken.

Since such handles are permanently connected with the cables, breakage of a handle requires not only a new handle but a complete relatively long cable with a handle afttached. l

Thus, with the conventional test box construction, breakage of a handle entails considerablefinancial loss aswell as a'ldssj of time required for the replacement of a unitary cable and handle."

It is "accdrdinglya primary object of this invention to provide ahandle for an output cable of a ground test.

box which is detachabl'y connectable with the cable whereby upon 'breakage of the handle, a new handle may readily be substituted therefor'with a retention of the cable. i

A further object of the invention is toprovide a handle which not only has provision for detachable connectionwith anoutputcable of a ground test box but which of itself comprises readily separable parts, whereby upon breakage o f 'one or more parts, same may readily be replaced, withoutthe. necessity of providing an entire new l Other objects and advantages of the invention will become apparent in thecourse of the following detailed description, taken connection with the accompanying drawings, wherein:

Fig. 1; is; an axial sectional view of the tubular handle body.

BracketedFig. 2 is an isometric exploded view wherein the cooperating handle elements are shown in a designa'te'd'order' of assembly Within and upon the handle body.

Fig. 3-isia engagemen view of the complete haudle s'tructure in accordance with a preferred structural mbqdime t ls iof-v Fig; 4,v s. an end elevationalview asobserved from the.

lef t'o f Fig. 3.. "ivitlitth'ej cabl eibeing. omitted Patent M 2 ,95

ice

fig. 5 is a transverse sectional view as observed in the plane of 5T5 on Fig. 3.

Fig. 6 is a longitudinal axial sectional view of the improved handle.

Fig. 7 is a broken diagrammatic top plan view of a conventional test box with which the improved handle in accordance with the present invention is used.

Fig. 8 is an isometric View disclosing a slight modification of the invention.

For a better understanding ofthe purpose of the present invention, reference will first be made to Fig. 7 wherein the diagrammatically disclosed test box T. includes a generally rectangular control enclosing and supporting housing H which is supported on wheels W for transportation thereof from one testing position to another.

The control means includes selectors S and pilot lamps L.

The housing is provided with an electric plug-in cable C and is also provided with a pair of outlet cables C and which are provided with terminal handles h.

The purpose of a test box which is generally understood by those skilled in the art is to ground test structures, such as generators, electric fans and the like and in the testing operations, the handles provide the test leads which embody picks whose free ends are engaged with the structures being ground tested. a

The cables C indicated as broken in Fig. 7 are in practice of substantial length for unobstructed movement of the handles h to desired testing positions.

While the. handles, with which test boxes have heretofore been provided, satisfactorily fulfilled their functions so far as ground testing was concerned, it has been observed that such handles often receive rough usage and are often dropped resulting in same being broken and rendered unserviceable.

1n the test box structures now in use, the long cables- C are provided with handles which are in eifect unitary therewith whereby upon breakage of a handle, same together with the entire cable C mustbe replaced.

The improved handle. in accordance with the; present invention and; which wholly overcomes the above noted objections to existing handles, comprises a tubulan han: dle body 19 which, as indicated in Figs. l and 6, includes inner and outer, tubes 11. and 12 respectively which are of electrical insulating material and which are of equal length but of different diameters leaving a space therebetween, and a shorter metal tube 13 is disposed within the space between the tubes 11 and 12.

The purpose of the metal tube 13 is to reinforce the tubular handle body and render same immune to break ing upon impact with another body. Suitable insulating. collars 14 may be disposed between the inner and outer insulating tubes 11 and 12- at the opposite ends thereof and all described parts of the tubular handle body are suitably adhered into a unitary structure. The various elements entering into the. handle structure and which are operatively associated with the handle body will be The sleevelS: is provided with an arcuatenotch 16 which in assembled position with the handle bodyaligns- Witha corresponding-notch 17: inv the tubularhandle body.

The ,opposite, ends of? the. sleeve 15 provide positioningt.

shoulders 1.18 -and 19 fm? a.- purpose .to be referred to.

A dish; 29 is providerln with-.acentral aperture 21;:for.

' of the cable C.

receiving the tubular handle body and prior to the assembly of the disk same is provided with a microswitch 22 having a depressible switch button 23 and which is secured to the disk by means of a pair of screws 24 which extend through apertures 25 'in' the micro-switch and whose free ends are engaged in tapped apertures 26 in the disk. i

A finger engageable switch operating member 27 is pivotallysecured to the disk by means of a screw 28 extendable through a sleeve 29 disposed within an aperture 30 in the member 27 "and through an aperture 31 in the disk.

A retracting spring 32 has one end thereof secured to the switch operating member 27 and the opposite end of the spring bears on sleeve 15 in the assembled positionof the disk. A stop pin 27 projects from the disk and limits retraction of member 27.

With the micro-switch 22 and operating member secured to the disk 20 as above described, the disk is entered over the right hand end of the handle body 10 until the face of the disk surrounding the central aperture -21 therein engages the shoulder 18 on sleeve 15. V In the positioning of the switch equipped disk as above, a key 33 which is threaded into a tapped opening 34 in the handle body ltlis received within a keyway 35 open the handle for exposure of leads 38. 'With the cable then prepared, it is drawn through the handle body 10 from left to right with respect to Fig. 6 and is provided with a winding of tape 39 which upon subsequent drawing of the cable from right to left engages the inner end of sleeve 36 Which, together with the tape winding, precludes the handle from being withdrawn from the adjacent end With the cable in proper position, the exposed end wires 40 will project slightly in advance of .the right hand end of the handle body 10.

After the cable is thus positioned, the leads 38 are drawn through the aligned notches 16 and 17 and secured to the screws 24.

After the cable has thus been connected to the microswit-ch 22, a collar 41 is moved over the left hand end of the body It! until the advance edge thereof engages the,

disk 28, the collar being of a circumference to circumscribe the micro-switch 22 and the switch operating member 27 as is indicated in Fig. 5.

A second disk, 42, having a central aperture 42 is next moved over the left hand end of body 10 until it contacts the adjacent edge of collar 41 and shoulder 19 and thereafter a plurality of screws 43 are extended through countersunk openings 44 in the disk 42, and which screws have their threaded ends engaged within tapped openings 45 in the disk 20.

It will be observed from Fig. 5, that the three screws 43 are disposed externally of the collar 41 and since the collar and the disks are of insulating material, the screws are effectively insulated from the switch and the wiring, whereby the usual practice of directly insulating the screws is wholly overcome; Furthermore, the collar and the disks provide a housing for the switch which is prevented from axial movement by the sleeve 15 and from rotative movement by the key'33 and the cooperating keyreadily removable parts and which comprise a sleeve 47 '4 of insulating material receivable within the right hand end of the body 10.

The sleeve 47 is provided with tapped openings 48 in which are receivable the inner ends of a plurality of screws 49 which areextendable through countersunk openings 50 in the right hand end of the tubular body 10.

An externally threaded tubular member 51 has one end portion thereof threadedly engaged with the inner wall of sleeve 47 and the other protruding end portion is provided with diametrically opposed slots 52 through which the wire ends'40' are extended as indicated in Fig. 6.

A pair of nuts 53 are threaded onto the slotted end of member 51 with the wire ends 40 clamped between the same.

A pick member is threaded onto the member 51 externally of the outermost nut 53 and the same comprises a nut member 54 to the outer end of which is rigidly secured a pick 55.

In the modified construction shown in Fig. 8 the sleeve 15 is provided with an integral lug 56 which provides a key receivable within the keyway 35 in thedisk 20, which does away with the tapped opening 34 and the threaded key 33. i 7

While as indicated in Fig. 7, two handles h are provided and which are replaced by the handle of the present invention, only one of such handles isprovided with a switch, and the two handles being otherwise of like construction.

It should be appreciated from the foregoing disclosure,

that by the present invention, a handle for ground test boxes is provided which provides for ready replacement of an entire handle or one or more of the several removable elements entering into the handle construction.

While I have disclosed my invention in accordance with a single specific structural embodiment thereof, such is to be considered as illustrative only, and not restrictive, I the scope of the invention being defined in the sub-joined claims. a

What I claim and desire to secure by U. S. Letters Patent is:

1. A handle for a ground test box having a relatively I 'long outlet cable, comprising an elongated insulating tubular body for receiving one end of the cable, means at one end of the tubular body for restraining same against movement toward the end of the cable, a pick removably secured to the opposite end of the body, a

switch supported externally of the body. and intermediate cable, a switch supported by thetubular body externallythereof, said tubular body being provided with a-notch receiving leads from the cable for connection to said switch, said switch being supported within a housing dis-i posed externally of said tubular body, and a'finger receiv ing opening in a wall of said housing for access to'saidr switch.

3. A handle for a ground test box having a-relatively long outlet cable, comprising an elongated tubular body; for removably receiving one end of the cable, means removably secured to the tubular body for securing same to the cable, said tubular body comprising radially spaced inner and outer tubular members of insulatingmaterial,

an intermediate reinforcing tubular member of metal whose opposite ends are disposed axially inwardly of the corresponding ends of the tubular members, and an insulating collar disposed between said tubular members at each end thereof.

4. A handle for a ground test box including a relatively long cable having the outer insulation layer thereof removed for a predetermined distance from thefree end thereof for exposing a pair of leads spaced from the free end and bare wires at the free end; comprising a relatively long tubular body throughout the length of which an end portion of said cable is extended, a micro-switch supported by the body intermediate its ends and externally thereof and to which said leads are removably connected, a unit removably secured to one end of said body to which said bare wires are secured, said tubular body comprising a pair of equal length insulating tubular members disposed in telescoping relation with a space therebetween, and a reenforcing metallic tubular member of less length than said insulating tubular members disposed within said space and having its ends equally spaced from the ends of said insulating tubular members.

5. A handle for a ground test box including a relatively long cable having the outer insulation layer thereof removed for a predetermined distance from the free end thereof for exposing a pair of leads spaced from the free end and bare wires at the free end; comprising a relatively long tubular body throughout the length of which an end portion of said cable is extended, a micro-switch supported by the body intermediate its ends and externally thereof and to which said leads are removably connected, a unit removably secured to one end of said body to which said bare Wires are secured, a sleeve disposed within the other end of said tubular body, and a winding of tape on said cable engageable with the inner end of said sleeve for precluding removal of the handle from the cable.

6. A handle for a ground test box including a relatively long cable having the outer insulation layer thereof removed for a predetermined distance from the free end thereof for exposing a pair of leads spaced from the free end and bare wires at the free end; comprising a relatively long tubular body throughout the length of which an end portion of said cable is extended, a micro-switch supported by the body intermediate its ends and externally thereof and to which said leads are removably connected, a unit removably secured to one end of said body to which said bare wires are secured, a tubular sleeve surrounding said tubular body intermediate its ends, said sleeve and said tubular body being provided with aligned notches through which said leads are extended, a pair of disks surrounding said tubular body, one engaged with each edge of said sleeve, said micro-switch being removably supported by one of said disks, a switch operating member pivoted to said last disk and the other disk being provided with an opening for receiving a finger for actuating said switch operating member.

7. The structure according to claim 6, together with a collar disposed between said disks adjacent their peripheries, and a plurality of circumferentially spaced screws extended through said disks in engagement with the outer periphery of said collar.

8. A handle for a ground test box including a relatively long cable having the outer insulation layer thereof removed for a predetermined distance from the free end thereof for exposing a pair of leads spaced from the free end and bare wires at the free end; comprising a relatively long tubular body throughout the length of which an end portion of said cable is extended a microswitch supported by the body intermediate its ends and externally thereof and to which said leads are removably connected, a unit removably secured to one end of said body to which said bare wires are secured, said unit comprising an insulating sleeve removably supported within said one end of said body, an externally threaded metallic member having one end portion thereof threaded into said sleeve and the other end portion projecting from the sleeve and said one end of the body, said projecting end having diametrically opposed slots through which said bare wires are extended, a pair of nuts on said projecting end in clamping engagement with said wires, and a pick member removably secured to said metallic member outwardly of said nuts.

9. The structure according to claim 8, wherein said pick member includes a nut member threadedly engaged with said metallic member and a pick rigidly secured to said nut member.

References Cited in the file of this patent UNITED STATES PATENTS 1,970,232 Hady Aug. 14, 1934 2,450,597 Karnoski Oct. 5, 1948 2,641,630 Goldberger et al. June 9, 1953

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