|Publication number||US2391076 A|
|Publication date||Dec 18, 1945|
|Filing date||Mar 4, 1942|
|Priority date||Mar 4, 1942|
|Publication number||US 2391076 A, US 2391076A, US-A-2391076, US2391076 A, US2391076A|
|Inventors||Stevens Daniel S|
|Original Assignee||Stevens Daniel S|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (3), Classifications (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Dec. 18, 1945. D. s. STEVENS 2,391,076
DEVICE FOR POSITiONING'COLORIMETER CELLS Filed March 4, 1942 I W 25. as
In venfol Patented Dec. 18, 1945 UNlTED STATES PATENT? OFFICE 2,391,016 DEVICE non POSITIONING ooLoRIMETEIt onus Daniel S. Stevens. Chicago, Ill. Application March 4, 1942, Serial No. 433,310
' This invention relates to a device for ing colorimeter cells.
One of the objects of this invention is to provide a simple means for properly positioning the colorimeter cell in the light beam of a photoelectric colorimeter.
Another object is to provide a means of securing the cell in place, once the proper position has been obtained.
A further object is to provide simple means for release of the cell after use. A, still further object is to provide means for ejecting the used cell into a suitable receptacle against future disposition.
One form of the device of this invention is illustrated by the attached figures, of which:
Figure 1 illustrates the device in front elevation showing the means for positioning and securing the cell.
Figure 2 is a plan view along line 22 of Figure 1.
Like numerals designate like parts throughout the several drawings.
The device consists of a holder member designated generally as l. The member I is pivoted at 2 to admit of circular motion. A handle 3 is grasped by the hand when it is desired to move the holder member about pivot 2. A stop post 4 is so positioned that it restricts the motion of I in a counter-clockwise direction. Arresting post 4 is provided with an adjustable screw 5, which may be screwed in or out, thus providing adjustable means for bringing holder member I into proper position when handle 3 is rotated in a counter-clockwise direction.
Holder member I is provided with an opening forming two sides of a square for receiving the colorimeter cell and bringing it into proper alignment. The side 6 of this square is given a sharp edge through beveling. Side 1 of the square opening need not be beveled.
A securing member 9 consists of a metal casting having substantial weight. An arm I extending from 9 co-operates with a stud ll, said stud acting as a pivot about which in may be turned. This securing member 9 serves to hold the colorimeter cell in place by exerting a side pressure on the cell. The edge of the securing member which contacts the colorimeter cell is also beveled, as indicated by [2. Member 9 is so suspended from stud II that the beveled edge l2 occupies the same horizontal plane as the beveled edge 6 of the holder member I.
If the beveled contact edges 6 and I2 were not in the same horizontal plane there would be a force tending to turn the colorimeter cell. Should position- 3 Claims. (01-. 88J-14) this occur the light path through the cell would be increased and an error in the reading 01 the instrument would occur. The beveled construction allows precise location of the holding force applied to the side of the cell.
A removable receptacle l3 provided in shelf I4 is so positioned that when securing member 9 is moved upward by turnin on stud Hand handl 3 is rotated in a clockwise direction, the cell th n in the device is ejected thereirom and drops into receptacle l3.
The many advantages of this device. particularly when used with colorimetric cells cover d by my U. S. Patent #2258973. become obvious on a description of its operation with a suitable ph toelectric colorimeter. 1
The light. source of such a colorimeter is a. small incandescent bulb I5 mounted on a movable platform [6. This bulb can be operated irom a storage battery.
The movable platform slides on posts I! and H by turning screw wheel I 8-. ".L'hisv screw wheel is mounted in threaded hub [9. Pressure from springs 20 and 20' gives a smooth motion to the movable platform 16.
Light from the bulb passes through conical opening 2! to reach the colorimeter cell 22. A small hole in the tip of hollow cone 23 allows light to enter and illuminate photocell 24. This photocell is connected to a galvanometer by leads 25 and 25'. Motion of the galvanometer cated by hairline 26 and a scale 21.
In using such an instrument, it is necessary to check frequently the zero position of the galvanometer, by cutting off the electric current through the galvanometer.
This is readily accomplished in the device of this invention by rotatingthe holding member I in a clockwise manner. When this is done, solid portion 28 of the holding member moves under the tip of the hollow cone, thus intercepting the light beam to the hotocell. Under these conditions the galvanometer hairline should return to zero, or the necessary adjustment can be made.
To make a colorimeter reading the holding member I is rotated, against stop 4, and a colorimeter cell 22 is placed in the square opening of I, while securing member 9 is held to one side by hand. The securing member is then released, bringing the colorimeter cell into correct position in the light beam by forcing the cell against beveled edge 6 through side pressure from edge I2. The colorimeter cell is thus positioned with little effort, which is a great convenience when many readings are required.
is indiunder test, is introduced into the colorimeter cell from a pipette. The colorimeter cell being of small dimensions retains the liquid by capillary action. -";'I ;'lie;g'alvanometer now has asmaller dieflectiondetermined by the amount of light absorbed by the liquid in the cell.
such position to aifect the light-beam intensity for a reading on the meter, said body portion being movable upwardly and away from the sample holder for release of the latter, and said holder means being mounted for movement parallel to said platform and across the aperture therein to move a, positioned sample-holder away from said aperture. h
j ":2. ma colorimeter having a meter, a source of light to project a light-beam in a path and means responsive to the intensity of the light- During this filling operation, the cell is held portingand positioning a sample holder in the securely in position, by pressure, between the se-v curing member and the holding" member, 517-1 released by raising securing" Upon completing a reading, the colorimeter cell can be instantly member 9 by hand. The used cell can then be, drawn directly out of the instrument with the other hand. However, a more convenient method ofdisposal is toejectthe cell into receptacle 13, This is accomplished by raising securing member 9 with, one. handand rotati ng holding member I with the other hand in'a clockwise direction. The colorimeter cell,whichjmay be of non-fragile plastic material, then drops into receptacle l3. This receptacle is held iniplatform H by a friction fit in tapered hole 29. After the receptacle is filled with cells, itis'readily removed and the cells, which are inexpensive, can be discarded.
As previously mentioned," each time a cell is ejected in the above manner the zero point of the galvanometer is automatically checked by interception of the light beam to the photocell.
.The novel features of; this invention provide a simple and convenient means for holding and ejecting colorimeter cells ina photoelectric colorimeter, especially when these cells are of small size and constructed from non-fragile, plastic materials. .r
What is claimed as new and useful and to be secured to me through Letters Patent, is given by thev appended claims.
1. In a colorimeter which has a light affected meter, a light-beam projecting light and a platform with an aperture in the path of the lightbeam adapted to carry a sample holder thereon, means for acting on a' sample holder to position and releasably retain the holder in a predetermined location on the platform in alignment with the aperture andin the path of the light-beam, said means including in combination holder means on said platform on one side of said lightbeam path, securing means having a body'portion, and means mounted above said platform pivotally supporting said body portion in a manner to permit pivotal movement thereof downwardly on the other side of the light-beam'path and toward said holder means toengage and position a sample holder in the light-beam path against said holder means and retain .the sample holder in beam for operating the meter, means for sup- "light-beam path, said supporting and positioning means including in combination an apertured platform with the aperture positioned in the light-beam path, holder means on the platform for retaining a sample holder supported by said platform in alignment with said aperture against movement in one direction, securing means pivotally supported above the platform in a position to move downwardly and toward the light-beam path to bear against the sample holder and urge the latter toward the holder means, a sampleholder disposal receptacle mounted in the platform, and means pivotally supporting the holder means for movement in a direction substantially parallel to the platform and across the aperture therein to project-the used sample holder into the receptacle.
3. In a colorimeter, the combination including a meter having a no-light reading, a source of constant light projecting a light beam in a path, photo-cell means responsive to the intensity of the light in the light-beam for operating the meter, a platform having an aperture in the light-beam path, walled hollow means mounted between the aperture and the photo-cell means to shield said photo-cell means from extraneous light, said walled means permitting the passage of light therethrough from the aperture, to the photo-cell means and spaced from the platform sufiiciently to permit the insertion of a sample holder therebetween, movable sample-holder-positioning-and-securing means having a portion on each of two opposite sides of the light-beam path and each portion being movable toward and across the light-beam path, one of said portions having an opaque part movable upon movement of said portion substantially parallel to the platform and between the platform and walled means into a position to shut off the light-beam com pletely prior to insertion of a sample holder in the colorimeter and to permit the operator to observe the no-light reading of the meter, and the other of said portions being mounted for movement away from the aperture and out of the path of said one portion to permit movement of said one portion and the opaque part thereof into said position for intercepting the light-beam.
DANIEL S. STEVENS.
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