Abstract
A light bulb changing device with expandable fingers which can grasp all light bulbs within a size range between 1 inch and 6 inches diameter and all shapes of light bulbs including incandescent, compact fluorescent and LED having a screw thread base. The disclosed device is extendable to allow a person to install and remove light bulbs from an elevated ceiling without need for climbing a ladder. The device provides for a user to controllably expand the fingers to insert or remove a bulb at both the proximal (bottom)and distal (Ceiling) ends of the device so that a user can reach up to the ceiling, open the fingers to grasp the bulb using the proximal actuation, remove it, bring it down to reachable level, remove the used bulb using the distal actuation, insert a new bulb using the distal actuation, elevate the bulb to the ceiling screw it into the socket and using the proximal actuation open the fingers to complete the job. The disclosed device controls the torque with which the fingers grasp the bulb to prevent separation of the glass bulb from the metal base.
Claims
1) a light bulb changing device comprising: a) a rod having first and second ends; b) at least two flexible fingers connected to the rod adjacently to the first end; having a predetermined curvilinear shape and a predetermined length; c) a horn slidably disposed on the rod and covering at least part of the flexible fingers, the horn being movable between a first position at a first distance from the first end and a second position at a second distance from the first end; d) a compression spring biasing the horn towards the first position; e) a flexible tension member connected to the horn and extending adjacently to the rod said tension member may be any one or combination of tension members like cable, rope, ribbon, wire, belt or the like; and; f) actuation of the device at the first end of the rod and; g) actuation of the device at the second end of the rod
2) the light bulb changing device according to claim 1 further comprising: a) a set of at least 2 rods, the second rod having a first and second end, the first end being approximately adjoined to the second end of the first rod, said rods may be telescoping tubes
3) the light bulb changing device of claim 2 further comprising at a second end of the second rod or tube a) a take up reel b) a drum c) a torsion spring to apply torque to the drum
4) the light bulb changer of claim 3 further comprising cable gripping means
5) The light bulb changer of claim 2 further comprising at least one pulley to reduce the force required to actuate the device
6) The light bulb changing device of claim 3 further comprising at least one pulley to reduce the force required to actuate the device
7) The light bulb changing device of claim 4 further comprising at least one pulley to reduce the force required to actuate the device
8) The light bulb changing device of claim 5 further comprising cable gripping means
9) The light bulb changing device of claim 2 further comprising cable gripping means
10) a light bulb changing device comprising: a) a rod having first and second ends; b) at least two flexible fingers connected to the rod adjacently to the first end; having a predetermined curvilinear shape and a predetermined length such that the fingers will open to hold a bulb between approximately 1 inch diameter and 6 inches diameter c) a horn slidably disposed on the rod and covering at least part of the flexible fingers, the horn being movable between a first position at a first distance from the first end and a second position at a second distance from the first end; d) a compression spring biasing the horn towards the first position and providing a torque to grip the range of bulbs at a torque between approximately 5 to 25 inch pounds of torque; e) a flexible tension member connected to the horn and extending adjacently to the rod which may be any one or combination of tension members like cable, rope, ribbon, wire, belt or the like; and; f) actuation of the device at the first end of the rod and; g) actuation of the device at the second end of the rod
11) the light bulb changing device according to claim 10 further comprising: a) a set of at least 2 rods, the second rod having a first and second end, the first end being approximately adjoined to the second end of the first rod, said rods may be telescoping tubes
12) the light bulb changing device of claim 11 further comprising at a second end of the second rod or tube a) a take up reel b) a drum c) a torsion spring to apply torque to the drum
13) the light bulb changer of claim 12 further comprising cable gripping means
14) The light bulb changer of claim 11 further comprising at least one pulley to reduce the force required to actuate the device
15) The light bulb changing device of claim 12 further comprising at least one pulley to reduce the force required to actuate the device
16) The light bulb changing device of claim 15 further comprising at least one pulley to reduce the force required to actuate the device
17) The light bulb changing device of claim 14 further comprising cable gripping means
18) The light bulb changing device of claim 11 further comprising cable gripping means
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a view of the full length of the disclosed light bulb changer, (to be abbreviated subsequently as lbc) showing the distal end with flexible fingers shown in the retracted position and proximal end shown with the retraction reel and handle.
[0025] FIG. 2 is a view of the distal end shown with the flexible fingers shown in the opened position
[0026] FIG. 3 is a view of the distal end shown with the flexible fingers in the retracted position.
[0027] FIG. 4 is a view of a portion of the internal mechanism located at mostly the distal end showing the compression spring and retraction cable and pulleys.
[0028] FIG. 5 is a view of the proximal end showing the cable retraction and gripping mechanism.
[0029] FIG. 5a is a cross sectional view of the cable gripper which is utilized to releasably grip the cable in a first direction while allowing release in a second direction.
[0030] FIG. 6 is a schematic view of the distal end with the flexible fingers in the retracted position and showing locations and directions of the forces which are applied to the flexible fingers by the compression spring.
[0031] FIG. 7 is a schematic view of the distal end with the flexible fingers in a first intermediate opened position and showing locations and directions of the forces which are applied to the flexible fingers by the compression spring.
[0032] FIG. 8 is a schematic view of the distal end with the flexible fingers in a second intermediate opened position and showing locations and directions of the forces which are applied to the flexible fingers by the compression spring.
[0033] FIG. 9 is a schematic view of the distal end with the flexible fingers in a fully opened position and showing locations and directions of the forces which are applied to the flexible fingers by the compression spring, and table 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0034] FIG. 1 shows, at a distal end of the disclosed light bulb changer, from here on to be abbreviated to lbc, flexible fingers 100, said fingers having a preferred curvilinear shape, said fingers shown in the fully retracted position, dimension A, a horn 110 which helps to control the position of the at least two flexible fingers, a tube 120 which encases a compression spring which is shown in FIG. 2. Also shown is a pulley housing 130, a small diameter extension tube 135, a small bushing 140 which provides a low friction sliding surface between said metal tubes such that metal does not slide against metal, an intermediate diameter extension tube 145, a large bushing 150 used to prevent metal-to-metal sliding, large diameter extension tube, said more than one extension tubes and said bushings combine to provide a set of at least two telescoping extension tubes to allow the user to expand or contract along an axial direction to provide for a greater or lesser axial length for the purpose of allowing the user to extend his reach to lower or higher positioned light bulbs, and at a proximal end of said lbc, a sliding handle which is fixedly connected to a take up reel 175, said sliding handle is slid in an axial direction opposite from the flexible fingers for the purpose of expanding the flexible fingers to a larger dimension suitable to grasp a variety of light bulb sizes, said bulbs having diameters between approximately 1.5 inches to approximately 5.5 inches, then said slide handle is released allowing said flexible fingers to grasp the light bulb at the preferred torque to assure bulb removal but limiting said torque to between approximately 5 and 25 inch pounds that will not cause the glass bulb to separate from the metal base of the bulb.
[0035] FIG. 2 illustrates said horn 110 shown expanded in an axially distal direction allowing said flexible fingers to be forced to a closed smallest dimension. Flexible fingers illustrated in FIG. 1 have a natural shape and a compressed shape. The compressed shape is of a dimension A to grasp the smallest of light bulbs. The natural shape of said flexible fingers is such that it is much larger than dimension A. Said horn is fixed to a tube 120. A compression spring 125 is shown in an axially largest condition. A connecting rod, 126 is shown, said connecting rod is fixedly connected to said flexible fingers on a central axis, said connecting rod also is fixedly connected to a pulley housing 130, said pulley housing encasing a moving pulley 124, a fixed pulley 121 and a pin 122. Said pin and moving pulley are moveable in a slot 128, provided in said pulley housing and said moving pulley and said pin are fixed to said tube. A cable 127, or any flexible tension member known in the art, having a first end and a second end is routed around said moving pulley, said fixed pulley and said second end is terminated at said pin. Said cable, said fixed and moving pulleys act together as a system to improve the mechanical advantage for an operator to more easily actuate said light bulb changer from the proximal end. Said cables first end is guided preferably through the annulus of tubes 135, 145, and 155 and guided to terminate said first end at said reel shown in FIG. 1. The function of adjusting said flexible fingers to a preferred dimension, dimension A or larger than dimension A, to allow the user to grasp a light bulb of a certain size is accomplished in a first method and a second method. The first method is utilized when an operator is removing a light bulb from a ceiling fixture. The operator first extends the telescoping pole to a preferred length to permit access to the bulb. He then grips the large extension tube with a first hand and grips the sliding handle with a second hand. He then pulls the sliding handle axially in a proximal direction which expands the flexible fingers to a preferred dimension to allow said fingers to grip the bulb. He then releases the sliding handle which allows the compression spring to force the horn in a distal direction to in turn apply force on the flexible fingers to grip the bulb. He then rotates the light bulb changer 10 and light bulb counterclockwise to unscrew the bulb. The second method is then used to extract the bulb from the grip of the flexible fingers and insert a new replacement bulb. The operator does this by placing the reel end against the floor of the room and with a first hand grips the tube 120 and with a second hand he grips the bulb. He then slides the tube in a direction toward the proximal, reel end of the light bulb changer thereby releasing the grip of the flexible fingers on the bulb.
[0036] FIG. 3 illustrates the light bulb changer 10 with said horn moved axially toward the proximal end of the light bulb changer. Said horn is shown in its fully proximal position which compresses said compression spring to its fully compressed condition. Said horn when in said position allows the at least two flexible fingers to expand to their fully expanded position of preferably between 4 to 6 inches.
[0037] FIG. 4 illustrates the light bulb changer 10 with said horn moved axially toward the distal end of the light bulb changer. Said horn is shown in its fully distal position which compresses said compression spring to its least compressed condition. Said horn when in said position forces the at least two flexible fingers to close to their fully closed position of preferably between 1 to 3 inches.
[0038] FIG. 5 illustrates the proximal end of said lbc. Slide handle 160 is fixedly connected to take up reel 175 which encases drum 180, said drum encases a torsion spring on a common axis, said torsion spring is commonly known as a clock spring, said torsion spring 182, having a first and second end, the first end is attached to the inside diameter of said drum said second is attached to a slot 186, in a spring axle 185 which may be molded as part of take up reel. Said reel also encases a cable gripper 190 shown in greater detail in FIG. 5a. Cable 127, being preferably fed through said annulus of said small medium and large diameter tubes from said distal end of the lbc is then guided through said cable gripper, then guided around said drum at least one full circumference and said first end of said cable is fixedly terminated on said drum. When the lbc is in a first condition of the extension tubes at their most fully extended axial length said drum will have a preferred at least one full circumference of said cable wrapped around said drum. In this condition said torsion spring will be at its most fully wrapped condition. When the lbc is in a second condition of the extension tubes being at their smallest axial dimension, said torsion spring forces said drum to rotate thereby wrapping said cable around said drum, and said torsion spring is at its least wrapped condition. When the operator locks said pole at a preferred pole extended dimension, said cable gripper is in its gripping position so that when the operator actuates said sliding handle said cable gripper will grip said cable so that said cable will actuate said pulleys and horn and flexible fingers at said distal end of said lbc.
[0039] FIG. 5a illustrates detail function of said cable gripper. Cable gripper 190 is comprised of a tapered housing 195, which has a conically shaped internal lumen. At least 2 spherical balls ride on said internal conical lumen and are forced to a smallest end of said conical lumen by a compression spring 201. An annular shaped sleeve 205, with a length and inner diameter and an outer diameter is placed around said cable. The purpose of said cable gripper is to prevent the cable from unwrapping from said drum when said first method of adjusting said flexible fingers to a preferred dimension is being used. As said slide handle is moved in an axial direction toward the proximal end of said lbc said balls are forced toward the smallest end of said conical lumen thereby gripping said cable and preventing said cable from unwrapping from said drum.
[0040] When an operator wishes to utilize said second method of adjusting the dimension of said flexible fingers, said cable gripper is in the condition where said balls are gripping said cable. The operator grips said tube with a first hand and axially slides said tube and horn in a proximal direction which moves moving pulley 124 and pin 122 to a reduced axial dimension to said fixed pulley 121 thereby making said cable to have slack since said pulleys have been moved closer together. The slack cable is then wrapped around said drum due to the torque imparted to said drum from said torsion spring.
[0041] When the operator wishes to extend said extension tubes to a longer axial dimension, said slide handle and reel and cable gripper are pulled in a minimally axially distal direction by the force of the operator extending said extension tubes until said cable gripper is stopped from said axial movement by wall 176 which pushes said sleeve 205 which in turn push balls 200 thereby releasing the balls' grip on said cable. Wall 176 may be molded as an integral part of said reel.
[0042] FIG. 6 illustrates said flexible fingers in a condition of being forced to their smallest dimension A by said Horn by contacting said flexible fingers at point 110b. Compression spring 125 produces a force F1 in an axially distal direction on said horn through an angle alfa which is the angle of said spring finger to said axis of lbc. Force F1 acting through said angle alfa produces a force Fb on said flexible fingers in a direction perpendicular to the axis of said lbc. Said flexible fingers then produce a force Fa on the perimeter of the light bulb. Force Fa is a normal force on the perimeter of the light bulb which causes a force of friction acting through the coefficient of friction between the light bulb and said spring finger. A stated object of this invention is to control the torque applied to said light bulb so as to not cause failure of the glass light bulb to metal base connection. Torque is a function of the following dimensions and angles illustrated in Table 1. Force F1, Force Fa, Force Fb, radius of bulb Rb, distance La-b, distance La-c and coefficient of friction between flexible fingers and light bulb.
[0043] FIG. 7 illustrates said flexible fingers in a condition being forced to an intermediate dimension B by said Horn by contacting said flexible fingers at point 110b. In this intermediate position of said horn, said compression spring is in a state of greater compression as compared to the position illustrated in FIG. 6 thus force F2 is higher than said force F1. Said Force F2, Force Fa, Force Fb, radius of bulb Rb, distance La-b, distance La-c are all different than illustrated in FIG. 6 as they change continuously as said horn to said flexible fingers position changes.
[0044] FIG. 8 illustrates said flexible fingers in a condition being forced to an intermediate dimension C by said Horn by contacting said flexible fingers at point 110b. In this second intermediate position of said horn, said compression spring is in a state of greater compression as compared to the position illustrated in FIG. 7 thus force F3 is higher than said force F2. Said Force F3, Force Fa, Force Fb, radius of bulb Rb, distance La-b, distance La-c are all different than illustrated in FIG. 7 as they change continuously as said horn to said flexible fingers position changes.
[0045] FIG. 9 illustrates said flexible fingers in a condition being forced to an intermediate dimension D by said Horn by contacting said flexible fingers at point 110b. In this position of said horn, shown in its most axially retracted position, said compression spring is in a maximum state of compression as compared to the position illustrated in FIG. 8 thus force F4 is higher than said force F3. Said Force F4, Force Fa, Force Fb, radius of bulb Rb, distance La-b, distance La-c are all different than illustrated in FIG. 7 as they change continuously as said horn to said flexible fingers position changes. Using the geometry and forces illustrated in FIG. 6 through FIG. 9 exemplary calculations are illustrated at said four positions of said horn to said flexible fingers resulting in predicted torques applied to light bulbs of dimensions A, B, C and D.
TABLE-US-00001 TABLE 1 The object is to calculate the torque applied to tighten of loosen the bulb Referring to FIG. 6 the spring force increases as it is compressed the force that the horn applies to the fingers changes due the angle alfa and the ratio of Lb-c/La-c the torque applied to the bulb increases as the bulb diameter increases Spring force is measured a the 4 different points Fb is calculated by dividing it by the tangent of Alfa Fa is calculculated by doing the sum of moments about C Fb Lb-c Fa La-c = 0 Fa = Fb(Lb-c/La-c) Torque applied to bulb = Fa coefficient of friction radius of bulb ANGLE ALFA RATIO FRICTION TORQUE SPRING FORCE ALFA RADIANS Fb La-c Lb-c Lbc/Lac Fa Rb Coefficient ON BULB F1 11.0 15.0 0.3 42.2 5.0 4.5 0.9 38.0 0.9 0.3 10.0 F2 14.6 20.0 0.3 41.3 5.0 3.6 0.7 29.7 1.4 0.3 12.3 F3 17.7 20.0 0.3 50.0 5.0 3.0 0.6 30.0 1.8 0.3 15.8 F4 21.0 17.0 0.3 70.6 5.0 2.1 0.4 29.7 2.3 0.3 20.6
[0046] Thus, the object of the invention to control the torque applied to the light bulb is demonstrated. The invention may have greater or lesser dimension, forces and angle alfa and are still within the scope of the invention
