Description

Combined Dipstick Breather Tube

—-• Technical..Field

This invention relates to dipstick devices and 5 in particular to a combined dipstick breather tube device.

Background Art

It is conventional in vehicles and the like hav¬ ing σrankcases or other housings holding liquid, such as lubricating oil, to provide a dipstick means for use in

10 measuring the level of the liquid or oil in the housing. It is further, conventional in connection with such dip¬ stick means to utilize a support tube through which the removable dipstick is inserted to have its lower end. ex¬ tend downwardly into the body of oil or liquid, thereby

15 to provide an indication of the level of the oil or liquid in the housing. Such structure is utilized to prevent .tur¬ bulence of the liquid from providing an erroneous reading of the level by effectively preventing such turbulence from . splashing or otherwise affecting the level of the liquid at

20 the dipstick.

In certain forms of dipstick devices, the dip¬ stick tube is further arranged to define a breather device. However, where the dipstick tube is so used, the lower end of the tube cannot be disposed below the normal level of

25 the liquid within the housing, otherwise the breather ac¬ tion is prevented. Where the tube is permitted to be dis¬ posed normally above the level of the liquid, a portion of ^' the dipstick is therefore- exposed to the turbulent movement of the liquid and erratic or erroneous readings are obtained.

30 Disclosure of Invention

The present invention comprehends an improved de¬ vice having means for measuring the level of liquid in a

housing notwithstanding- turbulence of the liquid therein and further defining breather means for passing gaseous fluids into and from the housing above the level of the liquid therein. More specifically, the invention comprehends providing such a device wherein a vent opening' is provided in the dipstick tube above the level of the liquid in the housing. The tube is preselected to have its lower end disposed within the body of liquid so that the dipstick extending downwardly through the tube is prevented from having the turbulently moving and splashing liquid from impinging thereon so as to effectively assure an accurate reading of the liquid level in the housing.

To prevent liquid passed inwardly through the ve opening from impinging on the dipstick within the dipstick tube, a baffle is provided therein inwardly of the vent opening. The baffle is arranged to define with the dip¬ stick tube a gaseous fluid flow passage between the open upper end of the dipstick tube and the vent opening so as to permit the desired breather action of the device. The baffle preventing the impingement of liquid passed through the vent opening onto the dipstick is further arranged to conduct that liquid back to the lower end of the tube and into the body of liquid in the housing. In the illustrated embodiment, the baffle define a tubular element. The tubular element extends downwardly within the dipstick tube to adjacent the level of the liqu in the housing so as to prevent impingement of the liquid passed inwardly through the vent opening onto any portion of the dipstick above the level of the liquid in the hous¬ ing being measured.

In the illustrated embodiment, the tubular eleme is centered coaxially within the dipstick tube by spacer means. In the illustrated embodiment, the spacer means comprise deformed portions of the baffle tubular element projecting outwardly into engagement with the dipstick tub wall.

Means may be provided for limiting the insertion of the baffle tube within the dipstick tube, and in the illustrated embodiment, comprise annular shoulder means on the dipstick, tube engaged by the lower spacing means 5 of the baffle tubular element.

The combined dipstick breather tube device of - - -the- present-invention is. extremely simple and economical of construction while yet providing the highly desirable features discussed above.

i0 Brief Description of the Drawing

FIGURE 1 is a fragmentary elevation of an appa¬ ratus including a housing containing a body of liquid and an improved combined dipstick-breather tube device embody¬ ing the invention for selectively determining the level of 15 the liquid in the housing;

FIGURE 2 is a fragmentary enlarged- diametric sec¬ tion of the combined dipstick-breather tube device; and

FIGURE 3 is a transverse section taken substan¬ tially along the line 3-3 of Figure 2.

20 . Best Mode for Carrying Out the Invention

In the illustrative embodiment of the invention as disclosed in the drawing, an apparatus generally designated 10 includes a housing 11 for holding a body of liquid L. Turbulence may be effected in the liquid by virtue of moving

25 elements 12, such as gears, etc. ^" Notwithstanding such tur¬ bulence, it is desirable to accurately measure the level of the liquid L at times.

The present invention comprehends an improved com¬ bined dipstick-breather tube device generally designated 13

30 for effecting such measurement and acting as a breather for the housing 11.

More specifically, device 13 includes a dipstick tube 14 having a first, lower end portion 15 extending down¬ wardly into the liquid L, an upper end portion 16 projecting

35 upwardly through a portion 34 of the housing 11, and a mid- portion 17 disposed within the housing above the level of the level L.

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A' dipstick generally designated 18 defines a low end portion 19 received within the lower end portion i5 of. the dipstick tube 14 so as to extend to below the upper level of the liquid L in the housing 11. The upper end 20 of the dipstick de ines a manipulating portion for faci itated movement of the dipstick into and outwardly from th dipstick tube, as desired. The dipstick further defines a midportion 21 disposed within the midportion 17 of the dip stick tube when the dipstick is installed in its normal inserted disposition within the dipstick tube, as shown in Figures 1 and 2.

To permit the dipstick tube i4 to further serve as a breather tube, a vent opening 22 is provided in dip¬ stick tube midportion 17 so as to cooperate with the. upper open end 23 of the dipstick tube 14 in defining a gaseous fluid flow passage communicating between the ambient atmos phere exteriorly of the housing 11 and the space 24 within housing 11 above the level of liquid L therein. Thus, tub 14 may serve as a breather tube for passing air inwardly into the space 24 and vapors outwardly therefrom, as may occur in the normal ^• operation of the apparatus 10.

As shown in Figure 1, the dipstick may include a breather cap 25 carried on its outer end portion 20 over¬ lying but spaced from the upper end 23 of the breather tub in the conventional manner.

The invention comprehends providing means within dipstick tube 14 for preventing impingement of liquid whic may inadvertently pass inwardly through vent opening 22 against the dipstick 18, or more specifically, against the dipstick portion 21 inwardly of the opening 22 and extendi downwardly therefrom to the upper level of the liquid L.

In the illustrated embodiment, the means for pre venting such impingement comprises a baffle generally desi nated 26 having a portion 27 disposed inwardly of the vent opening 22. As shown in Figure 2, the baffle extends down wardly from the level of the vent opening 22 to adjacent

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the upper level of the liquid L. In the illustrated embodi¬ ment, the baffle comprises a tubular element which is posi¬ tioned longitudinally coaxially within the dipstick tube. 14. More specifically, spacer means generally designated 5 .28 may be .provided at the _. upper end of.±he....b.affie..tube, above the level of opening 22 to center that end of the tube in the dipstick tube 14. The lower end of the baffle tube may be centered within the dipstick tube by lower spacer means 29. Thus, the spacer means 28 and 29 cooperate to

10 center the entire baffle tube within the dipstick tube so

^• as to define an annular liquid flow passage 30 therebetween. As shown in Figure 3, the spacer means 29 comprise integral portions of the lower end of the baffle tube pro- • r jecting- outwardly therefrom, into engagement with the wall

15 17 defining the midportion of the dipstick tube. The spacer means 29 are annularly spaced to define therebetween a plur¬ ality of openings 31.

Thus, any liquid which inadvertently passes through the vent opening 22 to within the dipstick, tube 14 is pre-

_-O vented from impinging on- the dipstick 18 and instead is caused to flow downwardly through space 30 and through the openings 31 back to the body of liquid L in the lower por¬ tion of housing 11.

In the illustrated embodiment, the dipstick tube

25 14 is inclined to the vertical so that such liquid is caused to flow along the lower side of the tube below the lower end of the baffle tube in returning to the liquid body L. As will be obvious to those skilled in the art, the baffle tube may. be arranged to extend fully downwardly to below

30 the upper level of the liquid if desired.

^• The ^" spacer" means 28 -is- reversely identical to the spacer means 29 and, thus, defines a plurality of openings 32 similar to openings 31. Openings 32 provide communica¬ tion between the ven passage 22 and the open upper end 23

35 of the dipstick tube 14 so as to provide for the desired breather action discussed above. The upper end of the baffle

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tube is disposed above the- level of the vent opening so as . to effectively preclude impingement of the liquid passing through opening 22 onto the upper end of the dipstick.

The baffle tube 26 may be positioned within the dipstick tube by means of an annular shoulder (33) formed in the dipstick tube adjacent the upper level of the liquid body L. Spacer means 29 may project into abutment with the shoulder 33 to limit the downward movement of the baffle tube to the position shown in Figure 2, thereby providing an automatic positioning means in the assembly of the device 13. As will be obvious to those skilled in the art, any suitable means may be provided for effecting the desired retention of the baffle 26 in the desired disposition with¬ in the dipstick tube. In the illustrated embodiment, the spacers 28 and

29 are formed integrally from the baffle tube. As will be obvious to those skilled in the art, any suitable spacing means may be provided in association with the baffle tube, as desired, the formed spacing means being illustrative of one novel arrangement only. Similarly,- any suitable means may be provided on -the dipstick tube 14 for cooperation with the baffle tube in effectively locating the baffle tube therein.' Alternatively, the baffle tube may be located within the dipstick tube by suitable apparatus and then fixed in such disposition as by welding, etc.

Industrial Applicability

The invention comprehends that the combined dip¬ stick-breather tube device be useful in all forms of indus¬ trial applicationswherein sensing of the level of a body of liquid within a container is to be effected with the measure ment being accurately made notwithstanding turbulence in the liquid being sensed.

^' The improved dipstick-breather tube device 13 may be utilized illustratively for determining the level of lubricating oil in a.gearbox, such as in the. illustrative

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embodiment 10 of apparatus embodying the invention. Further illustratively, the device 13 may be utilized in determining the level of lubricating oil in a crankcase, such as pro¬ vided in conventional vehicles, including tractors and the like-.- ^{1 "} The- improved-level measuring'-and -breather device is extremely simple and economical of construction and, thus,, may advantageously be utilized in a wide range of industrial applications.

Other aspects, objects and advantages of this in- vention can be obtained from a study of the drawings, the disclosure and the appended claims. The foregoing disclosure of specific embodiments is illustrative of the broad inven¬ tive concepts comprehended by the invention.

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