US2800248A - Instrument housing - Google Patents

Description

y 1957 F. w. TRUESDELL ET AL 2,800,248

INSTRUMENT HOUSING Filed Nov. 8, 1954 Fig.6

United States Patent 6 2,800,243 INSTRUMENT HOUSING Francis w. Truesdell, Dover, N. H., and Carl F. Van Bennekom, Lynnfieid, Mass, assignors to General Electric Company, a corporation of New York Application November 8, 1954, Serial No. 467,404 i 4 Claims. (Cl. 220-55) on such housings may be selectively clamped in place or removed therefrom as desired.

In the art of instrumentation there are many applications for a housing including a receptacle and a .cover removably positioned over an opening in such a receptacle, and it is often desirable to provide simple and effective means in such a housing to permit ready removal of the cover. For example, in the time switch art, such devices are in many instances enclosed within a weatherproof housing and are provided with a removable cover to permit selective setting of the switch for any predetermined time of the day. In the case of those switches that have their control setting frequently changed, the structure utilized for assembly and removal of the cover should be as simple as possible to permit changes in setting with a minimum of difficulty.

Briefly, the invention contemplates in one aspect thereof an arrangement of a receptacle and cover and a pivotally mounted clamping member in the form of a wire handle or bail that is selectively movable between a non-clamping and a clamping position by simple-pivotal motion. The wire handle is preferably made of a resilient deformable material, such as a stiff steel, and positive locking of the cover is achieved through a special camming arrangement that automatically moves the clamping portions of the handle into a position directly over a portion of the cover, after which the handle maybe moved to its clamping position during which suificient forces are developed in the wire to forcibly press it downwardly into the cover. The handle is slightly deformed while held in the clamping position, but it immediately returns to its original form upon release of the clamping forces.

A gasket may be used with the housing and the clamping forces developed by the improved clamping arrangements are effectively used to give a weatherproof seal between the cover and the receptacle.

Another feature of the design is the arrangement whereby the handle has to be moved through nearly its entire pivotal path to be in proper position for removal of the cover, and until it is moved to that position there is no danger of the cover accidentally coming off.

For all usual installation positions of instrument housings embodying the novel clamping arrangement, the cover can be easily removed and replaced with only one hand, thereby facilitating adjustment and setting of the unit.

The benefits and advantages ,of the invention will be more fully understood upon reference to the detailed description set forth below when taken in conjunction with the single sheet of drawings annexed hereto, in which:

Figure 1 is a perspective view of an instrument housing showing one form of a receptacle and cover, together with the improved clamping arrangements forming therewith the subject invention. In this view, the parts are shown with the cover clamped in place on the receptacle.

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arrangement shown in Figure 1, illustrating the coaetionbetween the flange engaging portion and the mounting means therefor, The parts are shown in the nonclamping position.

Figure 4 is a view similar to that shown in Figure 3 but with the parts shown in the intermediate position just prior to initiation of clamping forces.

Figure 5 is a view similar to Figures 3 and 4 but with the parts shown in the clamping position. 7

' Figure 6 is a composite partial view, in elevation, of the parts shown in Figures 3, 4 and 5, showing the three positions of the flange engaging portions superimposed on one another.

Referring now to Figure 1, there is shown an instru ment housing including the receptacle 7 and the cover 8.

The receptacle is shown as a substantially cylindrical body having one of its ends open to permit installation of any suitable instrumentmechanism. The particular receptacle shown is used for a time switch, and the posts 9 are provided within the receptacle on which to mount the time switch mechanism. A conventional threaded conduit extension 11 projects downwardly from the receptacle to permit wiring of the device in the usual manner.

As best shown in Figure 3, the receptacle 7 is provided with a shoulder 12 surrounding its open end, and this shoulder has the seat 13 which may be provided with a groove 14 into which may be cemented a sealing gasket in the form of the sponge rubber ring 15.

The cover 8 has an outwardly extending flange 16 surrounding its open end, and this flange is adapted to fit onto the shoulder 12 and abut that portion of the receptacle forming the shoulder seat 13. The cover is thus substantially tangentially with respect to the side walls of the cover 8. The portions 19 have their extremities curving 'rearwardly to form small arcuate sections 22, which in turn have their tips 23 bent outwardly at right angles to I provide pivotal arrangements for the clamping member 17.

Thus, the clamping member 17 is a substantially U- shaped member, and being formed of a relatively stiff steel wire, it is resiliently deformable in that any slight changes in configuration caused during the clamping operation of the member do not permanently change the configuration but only for so long as the deforming forces, are applied. It is to be noted that the flange engaging portions are said to have their extremities curving rear- Wardly, and this results from the fact that when the handle moves ina coveraclamping direction, it is said to be moving forward, in which case the direction of curvature is properly designated as rearward.

Cooperating with the clamping member 17 are the oppositely disposed mounting means 24 in the form of a pair of ears projecting upwardly from the receptacle 7 and formed integrally therewith, although such'integral construction is not necessary for. the proper functioning The portions 19 have straight sections 21 which in the clamping position are arranged of the mounting means. Here again, the mounting means are similar to one another, and like numbers have been assigned to the drawings to indicate similar elements. These mounting means are provided with suitable apertures 29 cooperating with the pivot shafts 23. As is best shown. in Figures 3, 4 and 5, the mounting means 2 5, which is the left hand means shown in Figure 1, has the first and second cam surfaces 25, 26, respectively, which cooperate in a unique manner with the flange engaging portions of the handle 17. The cam surface 25 is formed by a ridge member shown inclined downwardly toward the shoulder seat 13 from a point substantially opposite aperture 29 and the cam surface 26 gradually curves inwardly and rearwardly away from aperture 29 and continues until it issubstantially parallel to the side wall of the cover 8.

The manner of cooperation can be best described by following the coaction of the parts as the handle is retated from the non-clamping position shown in Figure 3 through the intermediate position shown in Figure 4 to the. final clamped position shown in Figure 5. These views are also shown in superimposed form in Figure 6. In the description of the mode of operation following, only one flange engaging section will be considered, it being understood that the two sections function in a similar manner.

Starting with Figure 3, we see that the arcuate section 22 is slightly above the cam surface 25, such that the tip 23 projects through the outside wall of the mounting means 24. In this position all parts of the clamping member overlie portions of .the receptacle and have no contact whatever with the cover 8, and the cover may be easily removed and the mechanism within the receptacle may be adjusted, serviced, repositioned, or the like.

When it is desirable to close the housing, the cover. may be repositioned on the receptacle such that its flange 16 rests upon the shoulder seat 13 and the clamping.

member is then rotated upwardly or forwardly in a coverclamping direction. For about the first 90 degrees of pivotal motion, the arcuate section 22 will be moving across the cam surface. 25, and since this cam surface is inclined inwardly towards the. flange lti, between it and the aperture 29, the effect of such motion will bring the arcuate section above the. cover flange 16. To accommodate this motion, the tips 23 will slide axially inwardly during the aforesaid pivotal motion. This position is shown in Figure 4, where the arcuate section 22 has just cleared the cam surface 25.

Continued pivotal motion of the clamp 1'7 through an angle of about 45 degrees will cause portions of the arcuate section '22 to move across the cam surface 26, and since this cam surface is inclined inwardly toward the side walls of the cover, the arcuate section will move further inward until it contacts the flange 16. In a like manner, the arcuate section on the opposite side of the cover will also contact the flange 16 and the cover side walls will be engaged by portions 22a of the handle. This point of engagement with the side wall will be slightly forward of the aperture 29 and will correspond to a distance between the side walls that is less than the distance between them taken across the aperture 2.9. The handle 17 is formed so that the normal distance between the side wall engaging portions 22a corresponds to the aforesaid lesser side wall spacing, so that any tendency for the portion 22a to move toward aperture .29 will cause the handle to be slightly spread by the cover side walls. With the handle forward so that its. outer ends are biased slightly toward each other, this action insures that the arcuate sections tightly grip the cover and align and center it on its shoulder seat. This is an important. advantage in that it permits a rather loose fit between the cover flange 16 and the shoulder 12 and prevents any possibility of the arcuate section getting between the edge of flange 16 and. the lower portion of the side wall. of. shoulder. 12.. Thus, we haveafirst, dc.- forming action that does some clamping but is primarily relied upon to align and center the cover on the receptacle. Since the rearmost portion 22b of section 22 is offset outwardly, as shown in Figure 2, continued pivotal motion adds to the aforesaid effect and enhances the aligning action.

The final clamping and positive locking takes place when the straight section 21-comes down on the cover. flange 16, and this position is best shown in Figures 5 and 6. A second. deforming action takes place during this phase of the clamping cycle and in this instance deformation takes place in the arcuate section 22 to generate forces in the wire that positively lock the cover in place. Thus, the normal ofiset spacing between the straight section 21 and the tip 23 is greater than the distance between aperture 29 and the top surface of cover flange ifi. When the handle comes down flat, the arcuate section must becompressed. to allow the parts to fit and this compressing force furnishes the. necessary clamping and locking forceto effectively. hold the cover inflplace.

Thus, it is seen that a positive clamping action is achieved and that the clamping member is virtually selflocking in the clamped position. To enhance'the selflocking characteristic suitable .detents in the form of grooves 27 substantially parallel to the shouldered seat 13 are provided adjacent the forward extremity of the 'base of each of the mounting means, into which por-- tions of the member 17 snap. It is-to be noted that the forward extremity of the base of the. ears 2d curves inwardly slightly whereby its inner wall intersects the wire clamping member when it. moves into the clamping position; such intersection permits the member 17 to snap into the grooves 27 to form a detent therewith. It is to be noted further that the. clamping forces developed drive the flange 16 against the gasket 14 to thereby efiec tively seal the housing and make itsubstantially weatherproof.

As is best seen in Figure 1, the receptacle 7 is provided with an apertured ear 28 contiguous to the handle 17 when it is in the cover-clamping position. This arrangement' will permit. the use of a conventional instrument seal of the type that is used to indicate any tampering with the device.

The normal position for installing the aforementioned instrument housing is indicated in Figure 1, wherein the sealing ear28 isat the top of the device. Should anyone desire to remove the cover, it is only necessary to remove the seal and. grasp the clamping handle 17 with. one hand and pull downwardly until the member rests. upon the bottom section of shoulder 12. The cover. can then be grasped by the hand and removed. Upon reassembly of the parts the coven is placed in position overlying the shoulderiseat 13, and the clamping handle 17 is then pulled upwardly until the parts are securely and positively locked in place. Operation and use are thus .quite simple, and the cover may be removed and replaced Therefore, while a particular embodiment of the subject invention has been shown and describedherein, it is in the nature of description rather than limitation, and

it will occur to those skilled in. the: art that various changes,

modifications, and cornbinationsxmay be made within the provinceof: the. appended claims, and without departing either in spirit or scope from this invention in its broader aspects.

The covers in many instances are What we claim as new and desire to secure by Letters Patent of the United States is:

1. lAIl instrument housing comprising, in combination: a receptacle having an opening therein, a shoulder formed in said receptacle surrounding said opening, a rem-ovably mounted cover for said opening having side walls and an outwardly flanged portion resting on said shoulder, a pair of apertured ears projecting upwardly from said shoulder on opposite sides of said cover, and a substantially U- shaped clamping wire pivotally mounted on said ears, each of the ends of said wire including rearwardly curving arcuate sections which in turn have their tips bent outwardly at right angles thereto, said tips being rot-atably and slidably mounted in said apertures, said clamping wire having a non-clamping position out of engagement with said cover, said clamping wire having a clamping position upon pivotal movement from said non-clamping position, said ears having a first cam surface inclined downwardly between said aperture and said shoulder, said arcuate sec tion cooperating therewith to slidably move said tips toward said cover, said ears having a second cam surface inclined inwardly and rearward-1y from said apertures, said arcuate sections cooperating therewith to maintain a clamping pressure on said side walls when said wire is pressed downwardly in a cover clam-ping direction, said clamping pressure serving to align said cover on said receptacle.

2. An instrument housing comprising, in combination: a receptacle having an opening therein, a shoulder formed in said receptacle surrounding said opening, a removably mounted cover for said opening having side walls and an outwardly flanged portion resting on said shoulder, means for selectively clamping said cover to said receptacle, said means comprising a pivotally mounted handle including a pair of interconnected flange engaging wire sections arranged tangentially on opposite sides of said cover, said wire sections having rearwardly curving arcuate cam follower sections which in turn have their tips bent outwardly at right angles thereto, and apertured mounting ears fiormed on said shoulders for rotatably and slidably receiving said wire tips, said ears including a first cam surface inclined downwardly between said aperture and said shoulder and including a second cam surface inclined inwardly and rear-wardly from said apertures toward said shoulders, said arcuate cam follower sections cooperating with said cam surfaces upon pivotal motion of said wires whereby said flange engaging sections are moved inwardly over said cover flanges and downwardly onto said cover to clampingly engage said cover flanges and said cover side walls.

3. The combination defined by claim 2 wherein said shoulder has a groove therein underlying said cover flange and a resilient deformable sealing member is placed in said groove to cooperate with said cover flange to etfectively seal said housing.

4. The combination defined by claim 3 wherein said mounting means also includes a forwardly disposed groove cooperating with portions of said wire sections to form a detent therewith to retain said wire sections in said clamping position.

References Cited in the file of this patent UNITED STATES PATENTS 477,955 Patterson June 28, 1892 597,051 Danz Ian. 11, 1898 1,026,093 Johnson May 14, 1912 2,572,629 Kolell Oct. 23, 1951 2,666,092 Balzer Jan. 19, 1954

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