US 2893563 A
Description (OCR text may contain errors)
E. W. BOTTU M Jilly 7, 1959 STRAINER Filed July 12. 1954 Fus. 1O
IN V EN TOR. E DWHED W. BOTTUM MpveM k/(m:
United States Patent STRAINER v Edward W. Bottlnn, Detroit, Mich. Applicatioululy 12, 1954,.Seiial No. 4 42,804 1 can. or. 21044113 This invention relates to an improved strainer construction. One of its applications is in refrigeration tubes.
An important part of the cost of providing a strainer in a tube or shell or the like is that devoted to mounting the strainer in place. If the mounting cost can be reduced it follows that the total costof the strainer is correspondingly reduced. V
It is an object of this invention to reduce thecost of strainer construction by reducing the mounting cost thereof. 1
More specifically it is ,an object to reduce the cost of mounting the strainer by avoiding the use of the conventional binding normally employed in the mounting operation.
As a further aid in reducing the cost of mounting the strainer it is an object to do away with the clinching operation normally employed when a conventional binding is utilized and substitute therefor a mechanism wherein the screen is merely set in the tube by hand and allowed the expand into gripping engagement with the sides of the tube under the influence of an ingeniously contrived spring mechanism.
Another object is to provide for quick and easy insertion of the screen and spring mechanism within the tube by the employment of a novel tool of such character that by a twisting motion thereof the spring will automatically be compressed for its subsequent expansion against the screen.
Beside the cost problem there exists the further problem of cleaning or replacing strainers after they have become worn or clogged with dirt.
It is an object of this invention to overcome this problem by providing a novel construction and arrangement for removably mounting the strainer in its tube, whereby it may be easily removed and replaced when desired.
Other objects of this invention will appear in the following description and appended claim, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.
In the drawings:
Figure 1 is a longitudinal cross sectional view of a tube which has positioned therein a strainer constructed according to the present invention,
Figure 2 is an end view of one form of mounting ring employed to mount the strainer in the tube,
Figure 3 is a side view of the ring shown in Figure 2,
Figure 4 is anend view of another form of mounting ring,
Figure 5 is a side view of the ring shown in Figure 4,
Figurefi is an end view of still another form of mounting ring,
Figure 7 is a side view of the ring shown in Figure 6,
Figure 8 is an end view of a further form of mounting ring,
Figure 9 is a side view of the ring shown in Figure 8, and
Figure 10 is a side view of a tool used to insert the mounting ring and screen shown in Figure 1 into the tube.
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings,
- since the invention is capable of other embodiments and of being practiced or carried out in various Ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
With more particular reference to the drawings and to Figure 1 specifically the construction there illustrated is seen to include a tube 1, a cone shaped screen 2, and a coil shaped mounted spring 3 having a radially projecting end portion 4 formed on the left end thereof. If desired tube 1 can be provided with a projection 5 at the inner end of spring 3 and a second projection (not shown) at the outer end thereof for preventing longitudinal movement of the spring and for assisting the spring to releasably hold screen 2 at its desired longitudinal location against the inside face of tube 1. However these projections are usually unnecessary since spring 3 alone will in most cases lock the screen in place.
Assembly of spring 3 and screen 2 into the body of tube 1 may be made in a number of ways. One method of assembly is to grip projection 4 with a tweezer and slide spring 3 into the screen. In order to facilitate entry thereof into the screen, spring 3 is tapered from left to right. After the spring is positioned in the screen and while projection 4 is still in the grip of the tweezers, the spring and screen can be inserted in tube 1 with a twisting motion. Initially the screen and wire will catch on the end portion of the tube, but as the twisting motion is continued the left end of the spring will be decreased in diameter enough to permit entry of the spring and screen into the tube to the position shown in Figure 1. When the tweezers are released from gripping engagement with projection 4, spring 3 will expand into tight and gripping engagement with the inside of screen 2. Removal of the spring and screen from the tube can be effected by twisting the spring as before and withdrawing the spring and screen.
If desired, assembly of the spring and screen within the tube can be accomplished with the tool shown in Figure 10. As there shown, the tool includes a body or handle portion 7 and a finger 8 having an arcuate notch or recess 9 therein. In the use of the tool, finger 8 is inserted through the body of spring 3 until projection 4 of the spring becomes seated in recess 9, after which the tool, spring and screen can be inserted in tube 1 with the same twisting motion that is employed when using a tweezer.
Although spring 3 has been found to perform effectively as a mounting means for screen 2 it is contemplated that other types of springs could be used. For example, a fiat leaf spring sudh as that shown in Figures 2 and 3 could be employed. If desired the leaf spring could be provided with projections 10 at its ends as shown in Figure 4. By squeezing the projections together the diameter of the leaf spring can be decreased for easy insertion thereof into the screen.
As another alternative to coil spring 3, ring 13, shown in Figures 6 and 7, could be employed. This ring is cup-shaped and cut away to form spring tongues 11 and circular aperture 12, the purpose of which is to allow passage of fluid into the tube and through the screen. As shown in Figure 7, ring 13 is tapered from left to right for easy insertion into the open end of screen 2. After the screen is in place on ring 13, the screen and ring can be moved into the tube with a straight line motion until tongues 11 force the screen into gripping engagement with the inside surface of the tube.
'The modified form of mounting ring shown in Figures 8 and 9' is similar to the ring shown in Figure 4 except that it is slit at points around its periphery to form a series of tabs 15. By bending out the tabs a series of sharp gripping edges 16 are formed. When the ring is in place edges 16 bite into the screen to hold it firmly against the tube.
In the course of the foregoing specification the'mount ing' rings have been described as associated with aconeshaped screen but it is obvious that other shapes of screen could be employed therewith.
The mounting rings constructed according to the instant invention are considered advantageous in thatthey can be produced at low cost and serve to eliminate the costly clinching operation normally employed in mount,- ing a strainer.
Another advantage of these mounting rings is the ease and speed with which they can be positioned their gripping positions within the tube or =s'hell.
A further advantage of these mounting rings is that they permit speedy removal and replacement of the strainer screen should it become clogged or worn.
In a strainer construction including a fluid flow tube, the combination comprising a screen including a strainerforming wall portion and a cylindrical wall portion extending therefrom in engagement with the tube interior surface; a coil spring Within said cylindrical screen portion and 'torsionally stressed to act expansively' in out,- wardly radiating directions so as to frictionally lock the screen within the tube; said coil spring having a plurality of convolutions, with the endmost convolution adjacent the strainer-forming wall portion of the screen being slightly smaller than the other endmost convolution; the extreme end portion of said other endmost convolution being turned inwardly toward the tube interior to form a tool-engageable arm; said spring being located in the screen with said arm turned from the position it occupies when out of screen so as to torsionally stress said other endmost convolution and reduce its size for accommodation of the spring; inthe screen and expansion of said screen against the tube interior surface.
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