US3929365A

US3929365A - Fluorescent tube changing device

Info

Publication number: US3929365A
Application number: US497877A
Authority: US
Inventors: Joe B Hunt; Nina E Hunt
Original assignee: Individual
Current assignee: Individual
Priority date: 1974-08-16
Filing date: 1974-08-16
Publication date: 1975-12-30
Anticipated expiration: 1992-12-30

Abstract

A fluorescent tube changing device comprising a semi-cylindrical tube gripper pivotally mounted to a pole by means of a wrist block and frame assembly which serves as a compound pivot joint between the gripper and the pole and allows the freedom of movement and the necessary degree of control required to render the device useful as a quick and effective means for removing or installing a fluorescent tube in its fixture from a remote position.

Description

1 Dec. 30, 1975 United States Patent [1 1 Hunt et al.

[54] FLUORESCENT TUBE CHANGING DEVICE 1/1958 Panzlca................................. 3,342,519 9/1967 Hunt et al....

[76] Inventors: Joe B. Hunt; Nina E. Hunt; both of 3,799,599 3 1974 Jordan..............1... ::::..1.:::... 294 20 3601 E. Orange Drive, Phoenix, Ariz. 85018 Primary Examiner-Robert S. Ward, Jr. Assistant Examiner.lohnny D. Cherry 22 Filed: Aug. 16, 1974 Attorney, Agent, or FirmWarren F. B. Lindsley 21 Appl. No.: 497,877

[57] ABSTRACT A fluorescent tube changing device comprising a semicylindrical tube gripper pivotally mounted to a pole by means of a wrist block and frame assembly which serves as a compound pivot joint between the gripper and the pole and allows the freedom of movement and [56] References Cited UNITED STATES PATENTS the necessary degree of control required to render the device useful as a quick and effective means for removing or installing a fluorescent tube in its fixture from a remote position.

Leibow 294/20 294/21 294/20 294/20 2 Claims, 4 Drawing Figures ma t. e "I "6 num df fen aw t BDS 5670 4445 9999 .1111 ll// 0 99 1 0022 20040 3 7 5374 00922 33 2222 US. Patent Dec. 30, 1975 FLUORESCENT TUBE CHANGING DEVICE BACKGROUND OF THE INVENTION Probably the most common type of artificial lighting employed today in factories, offices, stores and other large buildings is fluorescent lighting. Such installations commonly utilize large numbers of lamps with a single installation often utilizing several hundred fluorescent tubes.

As the individual tubes inthese large installations fail or lose their luminous intensity, they must be replaced. It has been found that the most efflcient maintenance practice in this connection is to replace all of the tubes in such an installation on a periodic basis as opposed to waiting for individual failures. The desirability of this practice rests on the inefficiency of changing only a few lamps at a time when the fluorescent tubes gradually lose their luminous efficiency and total light output and accordingly should be replaced periodically even though they havenot failed.

While such large tube replacement operations are often handled by maintenance personnel associated with the owners of the lighting installations, they are also quite frequently handled by small enterprisers who contract to perform these services for others.

In a typical installation the fluorescent lighting fixtures are several feet above the floor and are inaccessible except by means of a ladder or scaffold. Very often, the location of furniture or equipment directly below the flxture makes it inconvenient or even impossible to use ladders without moving the heavy furniture.

For these reasons and also because of the large numbers of lamps involved in a given installation, there is a need for a device which will permit an operator standing on the floor to remove and replace the tubes conveniently and quickly without the use of a ladder.

DESCRIPTION OF THE PRIOR ART Although US. Pat. Nos. 2,385,820; 2,504,152; 2,543,607; 2,589,642; 2,658,786; 2,669,478; 2,819,922; 3,lOl,2l2; 3,101,966; 9 3,129,970,

3,143,371 and 3,342,5l9 relate to lamp changing devices, none of them satisfy all of the requirements of the trade, and employ in some instances relatively complex mechanical assemblies. In many instances, no provision is made for rotating the lamps which are held by a twist-lock mechanism in the lamp sockets.

The mechanical structures of the prior art employ a number of fabricated metal parts which are expensive to manufacture and their designs have not been optimized for the best utilization of plastic molding and extrusion processes or for. the best use of plastic parts to insure the strength and durability of the working device.

SUMMARY OF THE INVENTION In accordance with the invention claimed, an improved fluorescent tube changing device is provided 2 the type utilizing twist-lock as well as spring-loaded sockets.

A further object of this invention is to provide an improved fluorescent tube changing device having a compound pivotal joint which permits a twist-lock fluorescent tube to be rotated about its axis for removal or replacement which device may be operated from an oblique angle with respect to the longitudinal axis of the tube as opposed to directly below the tube.

A still further object of this invention is to provide an improved fluorescent tube changing device which is simple in structure and which may be manufactured inexpensively utilizing molded or extruded plastic parts.

A still further object of this invention is to provide an improved fluorescent tube changing device which permits the easy removal or replacement of large numbers of fluorescent tubes in a very short period of time.

Further objectsv and advantages of this invention will become apparent as the following description proceeds and the features of novelty which characterize this invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be more readily described by reference to the accompanying drawing, in which:

FIG. 1 is a perspective view of the disclosed fluorescent tube changing device shown in relationship to a fluorescent tube shown in dash lines during a removal or replacement operation;

FIG. 2 is a cross-sectional view of a pivot joint forming a part of the device shown in FIG. 1 taken along the line 22;

, FIG. 3 is a cross-sectional view of the device shown in FIG. 1 taken along the line 3-3; and

FIG. 4 is a front view of the device shown in taken along the line 4--4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawing by characters of reference, FIGS. 1-4 disclose an improved fluorescent tube changing device 10 comprising a semicylindrical fluorescent tube gripper 11 to which is fixedly attached two hinge joints, 12A and 12B, a two part frame assembly 13, a wrist block 14 and a handle 15, the gripper being pivotally attached to the frame assembly 13 by means of a cylindrical shaft 16 which passes through cylindrical openings in

hinge joints

12A and 12B and an aligned cylindrical hole in frame assembly 13. The frame assembly l3'is pivotally attached to wrist block 14 by means of a cap screw 17 and a knob 18, the wrist block 14 being detachably connected by means of a threaded coupling assembly 19 to handle 15.

The semi-cylindrical tube gripper 11 comprises an elongated partially closed cylinder having narrow flanges 21 extending radially outwardly from the longitudinal edges of the semi-cylindrical configuration of gripper 11. The inner surface of gripper 11 is lined by FIG. 1

a cushioning and friction affording material 22.

' of tube 23 and causing the semi-cylindrical gripper 11 to spread apart slightly as the tube 23 is forced into the gripper. i

The resilient cushioning and friction affording material 22 protects the fluorescent tube 23 against mechanical shock and prevents it from slipping radially or longitudinally within the gripper during the tube changing operations. Materials suitable for this use include any number of tacky resinous materials, leather, sponge rubber or the like.

Hinge joints

12A and 12B are molded or extruded plastic parts having a central hollow cylinder bore 24 and two supporting

feet

25 and 26. The inside diameter of hollow cylinder 24 is slightly greater than the outside diameter of shaft 16 so that shaft 16 fits snugly inside cylinder 24 but is free to rotate therein.

Feet

25 and 26 are projections running at least a part of the length of one side of cylinder 24 which rise a short distance as two parallel planes and then break abruptly outwardly and apart from each other proceeding inopposite directions along an arc of a radius corresponding to the radius of curvature of the outer surface of gripper 11. The

mounting surfaces

27 and 28 thus conform to the outer surface of gripper 11 and may be readily and securely bonded thereto by a suitable plastic bonding material such as methyl ethyl keytone.

Running longitudinally along the edge of cylinder 24 opposite the location of

feet

25 and 26 are two additional substantially parallelly arranged projections or

flanges

29 and 30. One or both of the

hinge joints

12A and 12B may be forced together to reduce the inner dimensions of cylinder 24 by a threaded bolt 32 passing through a pair of holes 33 running perpendicularly through

projections

29 and 30. A wing nut 34, washer 35 and spring 36 may be employed to draw

projections

29 and 30 together.

The two part frame assembly 13 has the general form of a common clevis, particularly when viewed in crosssection, as shown in FIG. 3, wherein cap screw 17 serves as the clevis pin running through the diametrically positioned

holes

37 and 38 in its parts 13A and 138. These parts are fastened together at clevis neck 39 by means of four rivets 41-44 or the surfaces may be bonded together. Just above neck 39, the two counterpositioned parts 13A and 13B of frame assembly 13.

right angles to the

shoulders

46 and 47 running parallel and immediately adjacent each other through neck area 39 whereupon they break abruptly outwardly following the contours of circular bore 45 until they meet and terminate at point 48' on the circumference of bore 45. The inner surface of bore 45 is thus cylindrical in form. Surrounding

holes

37 and 38 in parts 13A and 13B and rising from the outer surfaces of these parts are two raised circular projections or

hubs

48 and 49. Projection 49 has a cavity shaped to contain and confine the hexagonal head of cap screw 17 to prevent it from turning. Projection 48 also has a cavity which must provide clearance for the body of cap screw 17 but for the sake of economy in production this cavity may have the same form as provided for in projection 49 so that parts 13A and 138 may be identical parts.

As shown in FIG. 1, parts 13A and 13B are molded with rib or web backs to reduce the weight and material content while still providing the required strength. Five vertical ribs 58-62, uniformly spaced across the breadth of neck 39, continue upwardly around the structure forming bore 45 adding rigidity to this portion of assembly 13. Of these five ribs, the center rib 60 differs from the other four. While the other four

vertical ribs

58, 59, 61 and 62 are simply low profile ribs, rib 60 is an elongated cam-shaped projection having a purpose hereinafter described.

Wrist block 14 has a diamond-shaped head 63 and neck 64 which is terminated in threaded coupling assembly 19. A circular hole 65 centered in the diamondshaped head 63 has a diameter slightly greater than the diameter of cap screw 17. Head 63 is tilted slightly relative to the vertical center line 67 of neck 64 so that one edge 66 of the diamond-shaped contour of head 63 is approximately perpendicular to the center line of neck 64. The wrist block 14 has a thickness dimension 68 which is somewhat less than the separation distance 69 between the inner surfaces of frame assembly 13. Wrist block 14 including head 63 and neck 64 is molded in rib and web form to provide strength of structure simultaneously with light weight. The overall width dimension 71 of head 63 is slightly less than the overall width dimension 72 of frame assembly 13.

The various parts of device 10 are assembled as follows.

The two parts 13A and 13B of frame assembly 13 are placed back-to-back as shown in FIGS. 1 and 3 with shaft 16 inserted in bore 45 of frame 13. With shaft 16 centered in bore 45 so that equal portions of shaft 16 extend from bore 45 at both ends, rivets 41-44 or the bonding of the surfaces occurs. Shaft 16 is now fixedly and non-rotatably confined within bore 45 and forms a single unit with frame 13.

Hinge joints

12A and 12B are then slipped over the protruding ends of shaft 16. The

feet

27 and 28 of

joints

12A and 12B are then bonded to the undersurface of gripper 11 as shown in FIGS. 1, 3 and 4.

Gripper 11 is now pivotally mounted by means of

hinge joints

12A and 12B and shaft 16 to frame assembly 13. Wrist block 14 is then inserted between the parallel faces of parts 13A and 13B of frame assembly 13 with the wrist block hole 65 aligned with

holes

37 and 38. Two

circular friction washers

74 and 75 are inserted one on each side of wrist block 14 with their central holes aligned with

holes

37, 38 and 65. Cap screw 17 is then installed through

holes

38, 65 and 37. Coil spring 76 is then slipped over shoulder 48 of part 13A of frame assembly 13 with a cup washer 77 slipped over spring 76 as shown. Knob 18 is threaded over the protruding end of screw 17 which is tightened against cup washer 77 thereby compressing spring 76 against frame assembly 13. Two parts 13A and 13B of frame 13 thus are drawn together thereby increasing the pressure between the mating surfaces of frame 13,

friction washers

74 and 75 and wrist block 14. Wrist block 14 The completely assembled device is seen to have two pivotal axes which are mutually perpendicular, namely the rotation of gripper 1 1 about the axisof shaft 16 and the rotation of handle 19 and wrist block 14 about the axis of cap," screw 17 supported within frame 13. Resistance to rotation in both cases. is adjustable. As alreadydescribed, knob may be tightened or loosened to adjust freedom 'of r'otatiori of wrist block 14 about screw 17. The freedom, of rotation of gripper 11 relative to frame assembly 13 may similarly be adjusted by tightening or loosening wing-nut 34, thereby adjust- -ing the friction between hinge joint 12A and shaft 16. If

desired, hinge joint 12B also may be equipped with a screw 32, spring 36, washer 35 and" wing-nut 34 to provide additional frictional adjustment at that end of shaft 16. i

In operation to remove a twist-lock fluorescent tube, wing-nut 34 is preferably loosened to allow gripper 11 to rotate freely relative to frame assembly 13. In preparation for the removal of the lamp, the gripper is first allowed to fall into the starting position-78 shown in dash lines in FIG. 3, wherein gripper '11 rests against projection or stop 60 of frame assembly 13. The device 10 is then raised by means of handle and the gripper 11 is forced against the lamp until it snaps over the walls of lamp 23 containing it within the cushioning material 22. Gripper 11 at this time is still in the starting position 78. The top end of device 10 is then forced to move in direction 79, as shown in FIG. 3 by applying pressure to handle 15. As frame assembly 13 moves in direction 79, the restrained fluorescent tube 23 is r0- tated within its socket until its terminals become disengaged within its sockets. Tube 23 is then easily removed from its sockets and is lowered and removed from the gripper by the operator of the device.

To install a new tube, tube 23 is first snapped into gripper 11 by the operator, the gripper allowed to rest this time in position 81, shown in dash lines in FIG. 3. Device 10 and lamp 23 are then raised to the fixture and the pins of lamp 23 are slipped into the lamp sockets. Gripper 11 is still in position 81. Frame assembly 13 is then forced to move in direction 82, thereby rotating lamp 23 within its sockets to secure its pins therein. Device 10 is then drawn away to disengage gripper 11 from tube 23 and the operation is completed.

To change a single-pin type fluorscent tube, gripper 11 is locked in the upright position shown by the solid line illustration in FIG. 3. This is accomplished either by tightening wing-nut 34 or by utilizing screw 83 and slot 84 as shown in FIG. 4. Slot 84 is located on hinge joint 12A to receive the body of screw 83 as shaft 16 is moved longitudinally within

hinge joints

12A and 12B. The subsequent tightening of screw 83 within slot 84 secures shaft 16 within hinge joint 12A so that rotation of gripper 11 relative to frame assembly 13 is prevented.

To remove the single pin tube, gripper 11 is then slipped over the tube and the tube is forced by pressure applied to handle 15 to move along its longitudinal axis in the direction of its spring loaded socket until the opposite tube terminal is released from its socket. The tube is then removed from the spring loaded socket and lowered within gripper l 1 by the operator. A new tube is next snapped into gripper 11 and installed by inserting the first terminal into the spring loaded socket, compressing the spring loaded socket to insert the 0pposite terminal, etc.

6 The-pivptal action of the wrist block 14 within frame assembly 13 is an important convenience'factor incorporated into the design of device10. ln many instances furniture or equipment immediately below the fluoresthe .one shown by the solid line representation of FIG.

4 wherein handle l 5 is perpendicular to gripper 11, the other shown by the dash line image wherein handle 15 is oblique to the longitudinal axis of gripper 11 with edge. 66 of wrist block 44 bearing against inner surface 87 of frame assembly 13 to prevent further rotation. If such limits to rotation were not provided device 10 would be unwieldy and'awkward to operate.

A lightweight but'sturdy. device comprised almost entirely of molded plastic parts requiring almost no machining operations is thus provided. The design of the individual parts has been optimized to prevent over-stressing of individual parts without adding excessive weight to the device which would unnecessarily tire the operator.

Installation and removal of lamps is accomplished very quickly by an operator standing on the floor either directly below or from a position beyond one end of the fluorescent fixture. No time consuming cranking or lever moving operations are required, disengagement of the lamp being accomplished by nothing more than a quick sideward displacement of the head of the device applied by the operator through the handle. The total time saved in changing out large numbers of lamps by virtue of this and other operating features of the device is considerable.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

What is claimed is:

.1. A device for changing fluorescent tubes and the like comprising:

a generally semi-cylindrical head having interior surface means of the same size as the exterior periphery of a fluorescent tube arranged to be engaged therewith in response to transverse movement of said head toward the tube,

said interior surface means having a tacky resinous material thereon capable of sticking to the exterior periphery of the tube when contacted therewith so as to prevent sliding movement of said interior surface means with respect to the exterior periphery of the tube but to permit ready disengagement of said interior surface means from the exterior periphery of the tube in response to transverse movement of said head away from the tube,

and elongated handle connected with said head for effecting transverse movement of said head into engagement with the exterior periphery of a tube to be changed and a subsequent movement of said head with the tube engaged therewith to release the latter from its fixture and for effecting movement of a replacement tube engaged with said head into 7 securement with the fixture and subsequent transverse movement out of engagement with the secured tube in the fixture,

said elongated handle being connected with said head by means providing for a limited pivotal movement between said elongated handle and said head about a first axis parallel with the axis of said head and spaced closely to the periphery thereof to facilitate a partial rotational movement of said head about its axis when in engagement with a fluorescent tube of the type which is engaged and released from its fixture by a partial rotational movement of the tube with respect to its fixture,

said limited pivotal means comprising a pair of spaced cylindrical members fixedly secured to the center peripheral portion of said head,

a shaft means rotatably mounted within said cylindrical member and having an arm extending radially outwardly therefrom,

said shaft means being fixedly attached to said handle for rotation therewith,

said handle and said shaft means being movable arcuately a predetermined distance about said pair of cylindrical members until said arm engages the outer periphery of said head at which time partial rotational movement of said head about its axis occurs when in engagement with the fluorescent tube to release it from its fixture,

said limited pivotal means further comprising a pair of parallelly arranged juxtapositioned spaced surfaces connected along a common end to said shaft means,

stop means fixed to said handle and said handle being pivotally mounted between said spaced surfaces,

said stop means engaging said limited pivotal means upon rotation of said handle about the pivotal connection of said handle to said spaced surface, and

means for applying frictional force to said handle to control the ease of rotation of said handle between said spaced surfaces.

2. The device set forth in claim 1 wherein:

said means for applying frictional pressure to said handle comprises a spring bearing means mounted on the pivotal connection of said handle to said spaced surfaces for applying frictional pressure to the sides of said handle.

Claims

1. A device for changing fluorescent tubes and the like comprising: a generally semi-cylindrical head having interior surface means of the same size as the exterior periphery of a fluorescent tube arranged to be engaged therewith in response to transverse movement of said head toward the tube, said interior surface means having a tacky resinous material thereon capable of sticking to the exterior periphery of the tube when contacted therewith so as to prevent sliding movement of said interior surface means with respect to the exterior periphery of the tube but to permit ready disengagement of said interior surface means from the exterior periphery of the tube in response to transverse movement of said head away from the tube, and elongated handle connected with said head for effecting transverse movement of said head into engagement with the exterior periphery of a tube to be changed and a subsequent movement of said head with the tube engaged therewith to release the latter from its fixture and for effecting movement of a replacement tube engaged with said head into securement with the fixture and subsequent transverse movement out of engagement with the secured tube in the fixture, said elongated handle being connected with said head by means providing for a limited pivotal movement between said elongated handle and said head about a first axis parallel with the axis of said head and spaced closely to the periphery thereof to facilitate a partial rotational movement of said head about its axis when in engagement with a fluorescent tube of the type which is engaged and released from its fixture by a partial rotational movement of the tube with respect to its fixture, said limited pivotal means comprising a pair of spaced cylindrical members fixedly secured to the center peripheral portion of said head, a shaft means rotatably mounted within said cylindrical member and having an arm extending radially outwardly therefrom, said shaft means being fixedly attached to said handle for rotation therewith, said handle and said shaft means being movable arcuately a predetermined distance about said pair of cylindrical members until said arm engages the outer periphery of said head at which time partial rotational movement of said head about its axis occurs when in engagement with the fluorescent tube to release it from its fixture, said limited pivotal means further comprising a pair of parallelly arranged juxtapositioned spaced surfaces connected along a common end to said shaft means, stop means fixed to said handle and said handle being pivotally mounted between said spaced surfaces, said stop means engaging said limited pivotal means upon rotation of said handle about the pivotal connection of said handle to said spaced surface, and means for applying frictional force to said handle to control the ease of rotation of said handle between said spaced surfaces.

2. The device set forth in claim 1 wherein: said means for applying frictional pressure to said handle comprises a spring bearing means mounted on the pivotal connection of said handle to said spaced surfaces for applying frictional pressure to the sides of said handle.