US1709772A

US1709772A - Latch for instrument casings

Info

Publication number: US1709772A
Application number: US571299A
Authority: US
Inventors: Bennet B Bristol; Edgar H Bristol
Original assignee: Foxboro Co
Current assignee: Schneider Electric Systems USA Inc
Priority date: 1922-06-27
Filing date: 1922-06-27
Publication date: 1929-04-16
Anticipated expiration: 1946-04-16

Description

April 16, 1929. B. ELTBRISTOL.- ET Al. 1,709,772

LATCH FOR INSTRUMENT CASINGS -Filed June 27. 1922 Inveno .f- Beh/ne? 11.137213@ o, Eagan 11132925630?,

Patented Apr.. 16, 1929.

UNITED STATES :BENNET B. BRISTOL AND EDGAR H. BRIST OL, F FOXBORO, IMASSACHUSETTS,l ASSIGN- OBS T0 THE 4E'OXIBOBO COMPANY, 0F FOXBORO, MASSACHUSETTS, AICORPORATION 0F MASSACHUSETTS.

v Application filed June 27,

VThis invention relates to casings of 'the type used, for example, to enclose the mechanism of recording gages and like instruments and the object is to provide certain improvements'more particularly relating to the closure or door of such instruments whereby they will be rendered more efficient and convenient in use.

The invention will best be understood by reference to the following description of an illustrative embodiment thereof shown by way of example in the accompanying drawings, wherein:

' F ig. 1 is a front elevation of a casing such as would be used for a recording pressure gage with parts broken away;

Fig. 2-'s an elevation of the closure fastening;

Fig. 3 is a section on the line 3 3 of Fig.

2o 2 with thepadlock omitted;

Fig. 4 is a similar section showing the lid or door about to close; and

Fig. 5 is a section on the line 5 5 of Fig. 1.

Referring to the drawings, we have there illustrated an instrument casing having the cylindrical body portion 7 adapted to'be secured to a vertical supporting surface by means of the llange 9 and on which is adapted to close the/glazed door or lid 11 having (see Figs. 3 and 4) a cylindrical flange provided with a rabbet'13 adapted to fit over the edge of the cylindrical body portion 7 of the casing. .The door or lid 11 may be mounted on one side of the casing by a hinge 15 and is secured at a -dianietrically opposite point by a fastening preferably in the form of a hasp.

We will next describe in detail the particular form of hasp -herein shown as an example of our invention and which is an instance of an automatically engaging fasteninfg for the lid 11. As seen from Figs. 4 and 3, as the lid 11 closes on its hinges the cylindrical surfaces of the body portion 7 of the casing and the flange of the hd 11 move to lie substantially in the line of approach between them. A hinge leaf 19 is mounted on the flange of the lid 11, preferably by means of screws 21 inserted from the interior of the casing and tapping into the hinge leat` 19, and on thisleat is hinged the vslotted hasp 23 having an outturned end 25 and adapted4 to latch over LATCH FOR INSTRUMENT CASIN GS.

1922. Serial No. 571,299.

casing 7 by means of the exterior and interior nuts 29, the end of the shorter leg being presented closely adjacent the body 7 of the casing. There is thus formed a U- shaped loop which may receive a padlock as shown in Fig. 2 and which presents an 4end rounded both on theside toward the cover 11 and on the side away therefrom. The first rounded "surface, of course, constitutes a cam to move the hasp 23 to the left viewing Fig. 4 and as the hasp passes the top of the U it will ride down'the other rounded surface under the influence, of the spring 29 with a camming action tending to draw the cover 11 tightl;v down into position.

In accordance with our invention we provide means for resilientlyholding the hasp- 23 projected substantially perpendicular to the face of theI lid 11 and inthe line of approach between the two cylindrical surfaces as shown in Fig. 4 and the outturned end thereof constitutes a cam permitting the hasp to be displaced to the lt't in Fig. 4 to latch over the catch 27. Herein we haveshown a spring 29 securedbetween the flange oithe lid 11 and the hinge leaf 19 and having a short end 30 projecting at the interior and forming a stop to limit counterclockwise movement of the hasp and this spring has a reduced portion rebent over the face y of the hinge 19 and resting against the outer face of the hasp 23, normally holding it pressed against the stop 30.

To prevent overstraining of the spring when the end of the hasp is seized by the hand to unlatch the same We preferably pro- \vide a stop limiting clockwise movement of the hasp and herein a U-shapedmember 31 is provided with feet secured by the ends of the screws 21 and has an offset cross-bar overhanging the end of the spring 29 and adapted to make contact therewith when the latter is moved-to the left in Figs. 3 and 4.

`This cross-bar thus-constitutes a stop preventing movement of the hasp too far and overstraining of the spring and it furthermore covers the end of the spring and serves as a protection for the hasp mechanism from blows from the exterior.

The lid 11 in constructions of this kind is heavy vand as the-instrument is usually supported in the vertical position the lid tends to sag. It is important that'the lid close accurately with the rabbet 13 fitting over the body 7 of the casing and in particular the alignment of the slot of the h-asp and of the catch 27 should be preserved and this is importantin the case of an automatically acting closure fastener suchas the one described. If the parts .are out of alignment the hasp will not engage over the catch as intended. The illustrated embodiment of our invention shows one suitable form of hinge 15. The two hinge leaves 'are preferably secured to the cylindricalsurfaces of the casing and lid by means of screws "33 tapped into the same from the interior of the casing and one of the leaves (see Fig. 5) is provided with a long central knuckle 85 while. the other leaf is provided with the lateral knuckles 37. The pintle 39 is in- )serted through the aligned leaves and has a close it inthe central knuckle 35 and` is free to turn in the knuckles 37 so that the lid is mounted as it were on trunnions. By-this construction the bearing surface for the ,pintle is coeX'tensive with the overall dimension of the hinge which it will be understood must be -relatively restricted on account of the circular contour of the casing. The lid 11 is thus swung on two points relatively far apart and the tendency of the door to sag is counteracted and the alignment of the hasp and its catch is preserved. The construction furthermore facilitates lubrication of the hinge as the bearings are disposed at the outside. At the same time the structure is simple and readily assem-v bled.

We have described in detail the particular embodiment of our invention shown by way of example inthe accompanying drawings but it will'be understood that all the detailsl Yillustrated and specifically referred t0 inthe description are not essential to the invention in its broader aspects but represent a preferred embodiment thereof. The features and combinations which we consider new and desire to secure by Letters Patentv we shall express in more definite manner by the following claims.'

Claims- 1. In combination with two closure members having surfaces located when closed substantially in the line of approach between them, a hasp on one member resiliently displaceable outwardly to snap over a catch on the other, and a catch on said other member having a `rounded portion remote from the line of closure over which the hasp is drawn ightly to bring together the closure mem- EI'S.

2. In combination with two closure members having surfaces located when "closed substantially in the line of approach between them, a `hasp on one member resiliently displaceable outwardly to snap over a catch on the other, and a catch on said other member comprising a loop of wire to receive a padlock or the like and having` a rounded end to cam said hasp outwardly and on entering the same to draw it downwardly to contribute to the tightness of the closure.

3. In a closure of two members having surfaces located when closed substantially in the line between them a hasp for one member displaceable outwardly to snap over a catch on the other member and comprising a securing hinge leaf, a slotted hinge leaf pivoted thereto, a 'spring underlying said first leaf and rebent over said slotted leaf and a stop overlying the free end of the spring yto limit movement ofthe slotted leaf .against the spring.

4. In a closure of two members having surfaces located when closed substantially in the line between them a hasp for one member displaceable outwardly to snap over a catch on the other member and comprising a securing hinge leaf, a second hinge leaf plvoted thereto and a member beneath said hinge leaf having an end projecting to form a stop for said secondP hinge leaf to limit the movement in one direction to a position substantially in alignment with the first leaf, said member having at the opposite end a resilient rebent extension bearing on the second leaf to press it toward the stop.

5. In a closure of two members havin surfaces located when closed substantial y in the line between them a hasp for one member displaceable outwardly to snap over a catch on the other member and comprising a securing hinge leaf, a second hingeleaf pivoted thereto, a member beneath` said hinge leaf having an end projectin to form a stop for said second hinge lea to limit the movement in one direction to a osition substantially in alignment with t e 'first leaf, said member having at the opposite end a resilient rebent extension bearing on the second leaf to press it toward the stop anda stop overhanging said second leaf limiting its movement in the other direction.

6. A closure for two members having surfaces located when closed substantially in the line between them, a catch on one member, a

hasp on the other member comprising av slotted tinge leaf to engage over the catch and a securing hinge leaf, a U-shaped member having an elevated cross-bar to protectthe linebetween them, a Catch on one memas a nut to retain the securing leaf and a ber, a hasp on the other member Comspring passing through said member and prising a slotted hinge leaf to engage over bearing on the slotted leaf to, resist outward the catch and a securing hinge leaf, a U- swinging thereof and adapted to seat on 5 shaped member having an elevated orosssaid cross-bar as a stop. 15

bar toprotect the hasp mechanism and feet In testimony whereof, We have signed our overlying the securing leaf, screws entered names to this specification.' from the interior of said other member passing through the securing leaf and tapping 4 BENN ET B. BRISTOL.

- 10 into said feet whereby said member serves EDGAR H. BRSTOL.