US 2243106 A
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May 27, 94. R. J. LIMBERT 2,243,06
LAMP CHANGER Filed April 2, 1940 mwwwwww BY @m c?.
ATTORNEY Patented May 27, 151941 LAMP CHANGER Rollin J. Limbert, Conshohocken, Pa., assignor to Suction Cup Lamp Changer Co., Scranton, Pa..
Application April 2, 1940, Serial No. 327,421
This invention relates to lamp changers and has to do more particularly with lamp changers of the Vacuum cup type, and the invention has for its object the provision of an improved device of this character.
Suction cup lamp changers generally comprise a pole, at the upper end of which is a suction type gripping device for taking hold of -the lamp bulb which is to be removed or resockets which have been exposed to moisture or outdoor weather conditions. In this, and other similar cases, it sometimes requires much turning eiort to get the lamp out of the socket. Also when a suction cup and a lamp bulb are'rst pla-ced together for the purpose of attaching the lamp bulb to the suction cup, it is desirable that the suction cup be of such construction that it will not allow the lamp bulb to slip around in the cup before the process of rarefyng the air between the cup and the bulb has progressed suiiiciently to hold the bulb. Suction cup lamp changers heretofore manufactured have left much to be desired with reference to their torsional turning ability and their anti-slipping characteristics.
My invention contemplates the provision of an improved suction cup lamp changer.
A further object of my invention is to provide a suction cup for a lamp changer which will allow for a large amount of turning effort being expended on a lamp bulb being held by it.
It is a still further object of my invention to provide a suction cup for use with lamp changers which will not allow a bulb to slip on the suction cup when the bulb is being forced into the suction cup for purpose of rareflcation of air between lamp bulb and the cup.
Another object of my invention is to provide an anti-slip suction type gripping device.
In accordance with this invention in one form thereof a suitable suction cup is attached to one end of a pole and is arranged to have a gripping surface consisting of alternately placed smooth surfaces and roughened surfaces.
For a more complete understanding of this invention reference vshould be had to the accompanying drawing in which:
Figure 1 is an elevation of a suction cup lamp changer embodying my invention, parts being broken away to illustrate certain details of the construction;
Figure 2 is a sectional view of the suction cup shown in Figure 1, taken through the line 2--2 of Figure 1 and looking in the direction of the arrows;
Figure 3 shows an enlarged view of a portion of the gripping surface of the suction cup shown in Figure 1; y
Figure 4 shows a cross section taken through the line 4-4 of Figure 3;
Figure 5 shows an enlarged View of a portion of the gripping surface of a suction cup showing a modification of my invention; and
Figure 6 shows a cross section taken through line 6 6 of Figure 5.
Referring to the drawing, this invention has been shown in one form in Figures 1 to 4, inclusive, as applied to a suction cup lamp changer comprising a wooden pole I0 on the upper end of which is mounted a suction cup, shown generally vat II. The suction cup II is securely attached to the pole I0 by having a hole I2 into which pole I0 is securely fastened by means of screws I3. Cord I4 is attached to lip IS'and provides a means for releasing the grip of the suction cup Il Whenever this becomes desirable. It will be noted that the cord I4 extends. to the bottom of the pole I0 and is held in place by screw eyes I6.
The upper portion of the suction cup II, which may be made from any suitable exible material such as high grade rubber, is shown as having a deep gripping cavity I8, which I have chosen to show as being frustro-conical in form. The internal or gripping surface of this cavity I8 comprises alternately placed smooth portions 20 and roughened .or recessed portions 2|. It will be noted that the smooth surfaces 20, in the illustrated embodiment of my invention, take the form of a multiplicity of smooth concentricV rings. The roughened or recessed portions 2 I, in the illustrated embodiment of my invention takes the form of a multiplicity of knurled rings. I have chosen for the purpose of illustration to show these smooth rings 20 and knurled rings 2l as being alternately placed and as being concentric one with the other.
It is preferable, as shown best in Figure 4, to arrange the smooth surfaces 20 and the rough surfaces 2| insuch a manner, that the two types of surfaces 2|! and 2| which are adjacent to one another are not elevated with respect to one another. In fact, in the preferred embodiment of my invention, the knurled surface 2| and the smooth surface will be so positioned that when the linger is run over the internal surface of the suction cup Il, there will be felt no ridge or division in elevation between where the smooth surface 2i) ends and where the knurled surface 2| starts, and Vice versa. There will, however, pref-erably be felt a difference between the smooth surface 29 and the recessed surface 2|;
that is, the smooth surface 20 will feel smooth,
and the recessed surface 2| will feel rough.
In Figures 5 and 6 I have illustrated a modified form of my invention in which the roughened or recessed surface 2| is shown as comprising a multiplicity of small concave recesses 23. Also in this embodiment of my invention I have chosen to show a portion of the gripping surface of cavity I3 in which there is a difference in elevation between the smooth surface 2G and the roughened surface 2|. In fact, in this embodiment of my invention there will be felt ridges 24 is then'ger is passed over the surface of the gripping cavity I3. I have chosen, for purpose of illustration, to show the concave recesses 23 as beinghemispherical in shape, although manyother forms may successfully be used.
In the operation of this apparatus; if it is desirable to remove a lamp bulb from a socket in an elevated position, the suction cup is elevated to the bulb by means of pole I0. Then the surface of the gripping cavity I8 is placed in contact with the convex portion of the lamp bulb and the pole Il! is pressed toward the bulb until the air which was trapped between the bulb and the bottom of the cavity I3 is partly expelled. This rareiies the air in the bottom of cavity IS, thus causing the suction cup II to hold rmly the bulb.
When the cavity I8 is rst placed against the bulb it often happens that the axis of the bulb and the axis of the suction cup and pcgo I0 are not in the same straight line. When the suction cup II is forced against the bulb in this out-of-line manner there is developed a component of force which tends to slide the suction cup l sideways on the surface of the lamp bulb. This component of force, of course, becomes larger with an increase in the"outofline or the angle between the axis of the bulb and the axis of the suction cup II and pole It). In the lamp changer embodying my invention, I have chosen to provide recessed or roughed portions 2| on the gripping surface of cavity I8 of my suction cup II. These roughened surfaces 2| increase the frictional resistance between the bulb and the suction cup and thus help considerably to overcome any tendency of the suction cup II to slide sideways on the lamp bulb. Also the roughened or recessed portions 2| act as auxiliary suction cups and grip the lamp bulb before the main suction cup has a chance to get a good hold on the lamp bulb. |Thus it can be seen that my lamp changer is superior to ones heretofore manufactured, in that it will not slip sideways on a lamp bulb when it is pressed against the lamp bulb.
It should be noted at this pointthat the multiplicity of smooth surfaces 2G shown in the' form of rings are placed close enough togetherv so that at least one of them will contact any size lamp bulb placed into cavity I3 and thusinsure a good seal for the rarefied air trapped between "also at least one of the roughened surfaces 2| will come in contact with the surface of the bulb. When the pole I0 is turned in a manner so as to unscrew the lamp bulb from the socket the suction cup I| also turns. The turning of the suction cup II turns the lamp bulb, and the g turning or torsional effort delivered to the lamp bulb by my special suction cup is greatly increased due to the roughness of the surface 2| which is in contact with the bulb. Two reasons are set forth to explain this. First, the coefcient of friction between the lamp bulb and the suction cup I| is increased by the roughened portion 2| which contacts the bulb, and second, the small recesses in the recessed or roughened portions 2| act as auxiliary suctions cups and thus increase the adhesion between the bulb and my special suction cup. `Tests with my suction cup as compared to other suction cups not having my combination of roughened surfaces 2| and smooth surfaces 29 have borne out the above.
The operation of the embodiment of my invention shown in Figures 5 and 6 is similar to that described for Figures l to 4, and is obvious from the above description. The roughened surfaces 2I by means of the concave recesses 23 Y increase the cup to bulb friction and also act as auxiliary suction cups. At the same time smooth surfaces 20 act to trap the rareed air confined in the bottom of main gripping cavity I8. The ridges 24 do not materially interfere with the operation of surfaces 2B and 2| because the material of the suction cup is very iiexible. In fact, the ridges 24 help to keep the suction cup I from slipping sideways on the bulb.
From this it can be seen that my lamp changer is superior in anti-slipping characteristics and in torsional turning ability to suction cup lamp changers heretofore generally used.
What I claim as new and desire to secure by Letters Patent of the United States, is:
l. A lamp'changercomprising a pole, a suction cup of flexible material attached to one end of said pole, and a gripping surface on said suction cup, said gripping surface comprising rough and smooth surfaces placed alternately.
2. A gripping surface for suction cup lamp changers comprising alternate smooth and rough surfaces, these surfaces being elevated with respect to one another.
3. A lamp changer comprising a pole, a suction cup of flexible material attached to one end of said pole, and a gripping surface on said suction cup, said gripping surface consisting of two different types `of rings alternately placed.
4. A gripping surface for suction cup lamp changerscomprising smooth portions, and roughened portions placed alternately.
5. A gripping surface for suction cup lamp changers comprising a multiplicity of smooth rings, and a multiplicity vof recessed rings.
6. A gripping surface for suction Cup lamp changers comprising a multiplicity of concentric smooth' rings, and a multiplicity of concentric knurled rings.
7. A gripping surface for suction cup lamp changers comprising a multiplicity of smooth rings, and a multiplicity of rough rings, said rings being alternately and concentrically placed.
8. A gripping surface for suction cup lamp changers comprising a multiplicity of smooth rings, and a multiplicity of recessed rings, the recesses in said recessed rings consisting of concave spherical depressions.
9. A gripping surface for suction type gripping apparatus comprising a combination of smooth contact surfaces, and roughed anti-slipping sur-y faces.
10. A lamp changer comprising a pole, a suction cup of iexible material attached to one end of said pole, and a gripping surface on said suction cup, said gripping surface consisting of a multiplicity of smooth rings placed alternately with a multiplicity of recessed rings.
ROLLIN J. LIMBERT.