US 3835549 A
A level having a working surface provided with a machined opening so that a level vial mounted with its axis coincident with the central plane of the web of the level frame is visible through the opening from directly above the level. A window having downwardly depending bifurcated legs which straddle the web closes the opening and is secured in place by engagement with a pair of vial retaining caps which are fixed on the sides of the web. The outermost surfaces of the legs of the window are serrated to interlock with mating serrations of the inner walls of the vial retaining caps to accommodate dimensional variations of the machined opening and the window.
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Description (OCR text may contain errors)
[4 1 Sept. 17, 1974 LEVEL VlAL STATION ASSEMBLY Great Britain 33/381 Inventors: Maarten C. De Jong, Canton;
Antoni P. Gutowski, New Britain, both of Conn.
Primary ExaminerLouis R. Prince Assistant Examiner-Charles E. Phillips Attorney, Agent, or FirmPrutzman, Hayes, Kalb & Chilton  Assignee: The Stanley Works, New Britain,
T C A R T S B A H 5 3 7 9 l 3 3 8 7 W9 S3 0 N .ml 0. m0. FA NH 7.2
A level having a working surface provided with a machined opening so that a level vial mounted with its axis coincident with the central plane of the web of the level frame is visible through the opening from directly above the level. A window having downwardly depending bifurcated legs which straddle the web  Int.
 Field of Search 33/379, 381
References Cited closes the opening and is secured in place by engage- UNITED STATES PATENTS ment with a pair of vial retaining caps which are fixed 6/1973 on the sides of the web. The outermost surfaces of the legs of the window are serrated to interlock with mat- 2.8 .mm m0 m .m m e 5 a w .m W l omw m m n wmmm m m r e D .1 m u 1 a m hd um mmC m SOC 4 w w .1% t d a m m et-l S m wla .mCm 91111 7000000 BBBB 3333 S3333 N HUN 0 W I T m m A m..m C I: I L mmmm Di "nu" M mmmm W YMVZH mmma S m mm T rwhrm N ewef GSGG T A0328 P2355 9999 NHHHH G H l E 00620 08772 F 9444 2640 3 0000 LEVEL VIAL STATION ASSEMBLY This invention relates to levels used by carpenters, masons, and other artisans and is particularly concemed with a top-viewing level.
A primary object of this invention is to provide a topviewing level of rigid construction and simple design.
A further object of this invention is to provide a level having an opening in the working surface of the level above the vial and a window for closing the opening.
A still further object of this invention is to provide a top-viewing level having an aperture mounting a transparent window adjustably held in place by opposed vial retaining caps on the sides of the web of the level frame to form a dust tight enclosure for a level vial.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth.
BRIEF DESCRIPTION OF THE DRAWING The DRAWING is an exploded perspective view, partly in section and partly broken away of a portion of a level embodying the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown a level frame having a rigid I-beam configuration with two flanges 12 and 13, having parallel working surfaces 16 and 18, respectively, connected by a central web 14. The frame 10 is preferably made of metal so as to be warp free, and where light weight is desired, the metal employed may be one of the available alloys of aluminum, magnesium, or the like.
The web 14 is preferably provided with a plurality of longitudinally spaced apertures 20 each of which is dimensioned to receive a level via] 22. Each aperture 20 is provided with precisely and accurately aligned notches 24 and 26 for receiving the precision formed (to the same dimension as the notches) cylindrical ends 28 of the vial 22. The level vial 22 is shown as being mounted in the notches 24, 26 coincident with the plane of web 14 and parallel to the working surfaces 16 and 18, although any other predetermined angle may be selected.
As shown, a generally rectangular top viewing open ing 30 is machined through the flange l2 and is framed by the side margins 15 thereof so that the flange 12 is uninterrupted for strength and rigidity. The opening 30 is centered on the web 14 and is shown as having arcuate Shaped ends 32 formed in part as at 34 in the flange l2 and continuing on the web 14 as at 35 to intersect aperture 20 adjacent the notches 24 and 26.
It can be seen that the opening 30 with its arcuate shaped ends 32 can be readily made with a variety of circular cutting tools such as a milling cutter having a desired width and radius.
According to this invention a top viewing window 36 having novel mounting means is provided to cover and seal the opening 30.
As shown, the window 36 is a substantially rectangular member having a central transparent viewing section 38 flanked by non-viewing, knurled surface end areas 40. The ends 42 of the rectangular lens 36 are arcuately shaped so as to mate with the arcuate surfaces 32 of the opening 30. Adjacent these ends 42 are two pair of integrally formed downwardly depending legs 44.
The window 36 is inserted in the top viewing opening 30 (the width of the opening 30 and the lens 36 being substantially the same) with its bifurcated legs 44 straddling the web 14 (the space between legs 44 being substantially greater than the thickness of the web 14) and the arcuate ends 42 of the window bottomed on the arcuate surfaces 32.
An important feature of this invention is the means for seating and securing the window in the opening 30 so that it is flush with or below the working surface 16 despite manufacturing variations and tolerances.
As shown, the window is retained against the surfaces 32 by a pair of mating retaining caps 50. The caps have a viewing window 52 framed by a U-shaped channel 54 of the cap 50.
The wall of the cap 50 is provided with a pair of semi-circular recesses 62 to receive and engage the cylindrical ends 28 of the vial 22 when the caps 50 are assembled to the web 14. Walls 58 and 60 of the caps 50 also define pockets 64 for receiving the legs 44 of the window 36 and integral retaining lugs 68 having serrations 70 which are provided within the pockets 64 to engage serrations 46 of the legs 44 to secure the window 36 in place with the window bottomed on the arcuate surfaces 32.
During assembly, the window36 is inserted into the top viewing opening 30 with its legs 44 straddling the web portions 35 and the arcuate ends 42 of the window bottomed on the arcuate surfaces 32 to position the lens flush with or below the working surface 16. Thereafter, the vial 22 is mounted with its cylindrical ends 28 positioned in the notches 24, 26 and retaining caps 50 are assembled on the web 14 so that the semi-circular recesses 62 engage with the vial ends 28.
Self-tapping screws 72 are then inserted through clearance holes 74 in the retaining caps 50 and recesses 76 in web 14 to secure themselves in screw receiving bosses 78 formed integrally with the retaining caps 50. When so assembled, the serrations on the lugs 68 engage the serrations 46 on the legs 44 to secure the window firmly in place to form with the caps a dust proof chamber for the vial 22. As described above, the legs 44 have a clearance with web 14 so that the natural resiliency of legs 44 will cause the lugs 68 to resiliently engage the legs 44.
As will be apparent to persons skilled in the art, various modifications, adaptations and variations of the foregoing specific disclosure can be made without departing from the teachings of the present invention.
1. A level comprising a 'rigid frame provided with parallel working surfaces and a web interconnecting said surfaces, an elongated vial, said web having an aperture for mounting said vial with its axis substantially coincident with the plane of the web, an opening through one of the working surfaces and intersecting said aperture to expose said vial, a transparent window closely received in said opening and a pair of vial retainers overlying said aperture on opposite sides of said web for retaining said vial in said aperture, each of said retainers engaging said window to secure the same to said web, said window being provided with downwardly depending legs engaged by said retainers.
3 4 2. The device of claim 1 wherein said downwardly pair of downwardly depending legs which straddle said depending legs are provided with serrations which enweb and are resiliently engaged by said retainers for gage serrations formed on said retainers to adjustably locking said window in place mount said window thereby to accommodate manufac- 4. The level of claim 3 wherein said window and said turing variations and tolerances. 5 retainers form a dust proof enclosure for said vial.
3. The level of claim 1 wherein said window has a