US3637159A

US3637159A - Automatic carrier box latch of reduced dimensions

Info

Publication number: US3637159A
Application number: US860308A
Authority: US
Inventors: Luigi Caramella
Original assignee: Individual
Current assignee: Individual
Priority date: 1968-12-12
Filing date: 1969-09-23
Publication date: 1972-01-25
Anticipated expiration: 1989-01-25
Also published as: DE1956962B2; ES153924Y; ES153924U; FR2025969A1; BR6914984D0; DE1956962A1

Abstract

An automatic latch device for suspended bodies, such as electric light pendants and the like, comprising: a spherical segmentshaped box symmetrical about a plane passing through the center, the two shells comprising said box meeting on said plane and, in addition to being effective as containers, said shells being internally shaped so as to form a seating for members comprising the mechanism and forming part of said members as well. Inside the shell is a cylindrical cup drum, the carrying cable being externally wound thereon, for internally containing a coil spring, a disc having a central pin adhering to said spring, and a clutch plate wherein suitable seatings are formed for the clamping members with said drum. A pin fast with the rear shell has a diametrical slit for coupling the inner end of the spring about which said drum idling rotates, as well as a transverse pin for deviating said carrying cable. Outside the front shell a screw with a resilient washer is arranged and screws down in the pin of the disc adjacent said clutch plate; and a suitably shaped element is also provided for anchoring at the bottom both said carrying cable and the helical driving cable.

Description

United States Patent Caramella [451 Jan. 25, 1972 [54] AUTOMATIC CARRIER BOX LATCH OF REDUCED DIMENSIONS [72] Inventor: Luigi Caramella, Zona lndustriale Roc- [30] Foreign Application Priority Data Dec. 12, 1968 Italy ..24968 A/68 521 u.s.c1 ..242/107.3 51] 1m.c1 ..B65h75/48 [58] Field of Search ..242/107,107.1,107.11,107.12,

FOREIGN PATENTS OR APPLICATIONS 168,962 9/1951 Austria ..242/107.3

Austria.... ....242/107.3 Germany ..242/l07 Primary ExaminerStanley N. Gilreath Assistant Examiner-Werner H. Schroeder Attorney-Young & Thompson [57] ABSTRACT An automatic latch device for suspended bodies, such as electric light pendants and the like, comprising: a spherical segment-shaped box symmetrical about a plane passing through the center, the two shells comprising said box meeting on said plane and, in addition to being effective as containers, said shells being internally shaped so as to form a seating for members comprising the mechanism and forming part of said members as well. Inside the shell is a cylindrical cup drum, the carrying cable being externally wound thereon, for internally containing a coil spring, a disc having a central pin adhering to said spring, and a clutch plate where-in suitable seatings are formed for the clamping members with said drum. A pin fast with the rear shell has a diametrical slit for coupling the inner end of the spring about which said drum idling rotates, as well as a transverse pin for deviating said carrying cable. Outside the front shell a screw with a resilient washer is arranged and screws down in the pin of the disc adjacent said clutch plate; and a suitably shaped element is also provided for anchoring at the bottom both said carrying cable and the helical driving cable.

5 Claims, 7 Drawing Figures AUTOMATIC CARRIER BOX LATCH 01F REDUCED DIMENSIONS This invention relates to an automatic latch device having both extremely reduced overall dimensions and highly desirable construction details.

The dimensions and compact form thereof allow the use of concealment decorative closure plates, the overall size of which is not larger than that of common decorative closure plates as used for electric light pendants not fitted with latch means. Therefore, the use of the automatic means according to the present invention will not lead to any adverse result from an aesthetical standpoint.

As to the structural construction, the members comprising the mechanism have been reduced to the smallest possible size, giving such forms and shapes thereto as to allow for a correct operation of the device notwithstanding the reduced dimensions thereof.

The symmetrical shell shape of the box substantially facilitates the latch-assembling operations and the inner walls thereof form integrating parts of the device in addition to being effective as seatings for the other members.

Another member which has required particular care in designing is the clutch disc or plate which, by using three suitably proportioned rollers assures the mechanism operation notwithstanding the restricted dimensions of the drum wherein said clutch plate is inserted.

The characteristics, as above set forth in short, permit reducing the number and dimensions of the mechanism components and making the several assembling steps extremely simple, and allow a convenient mass production of the mechanism with resulting low costs.

The present invention also comprises, as an integrating part thereof, the joint terminal for the helical cable to the overhung body, the particular shape of which facilitates the coupling thereof and prevents the helical cable from coming out of the sleeve.

More particularly, the device comprises two shells almost equal and symmetrical to the vertical matching plane and which, besides containing the other mechanism components, are internally shaped so as to form a part ofthe mechanism.

Internally, a cylindrical cup drum is mounted on the external periphery of which is wound the carrying cable and the cup is adapted to hold a coil return spring, a disc fast with the central pin and a shaped clamping member with three stop rollers. The braking action is provided by the friction developing on the outer sides of the clamping member as a result of the pressure being exerted on one side by the disc fast with the pin and on the other side by a suitable washer. This clamping member is adjustable by tightening or unloosening a screw on the shell outside and the stem of which is screw threaded within the pin provided with said disc.

In the more detailed description of the invention, reference will be had to the accompanying drawing, wherein the preferred embodiment of the device is shown and which, how ever, is to be construed only as exemplary and not in a limiting sense.

In the drawing:

FIG. 1 is a front view ofthe device;

FIG. 2 shows the device in FIG. 1 as rotated through 90;

FIG. 3 shows the shell in FIG. I as seen from the inside with the lower associated elements removed;

FIG. 4 shows the rear shell with the inner elements;

FIG. 5 is a sectional exploded view showing all the elements comprising the device;

FIG. 6 is a view showing the coupling-shaped member for the helical cable at its lower end; and

FIG. 7 is a top view ofFIG. 6.

As shown in the drawing, box 8 is in the form of a segment of a sphere symmetrical to the plane passing through the center, the two

shells

9 and 9 comprising the box meeting on said plane and being kept together by an upper screw 10 located sidewise of the slot II for hanging the device to the ceiling, the slot being formed with two flanges l2 projecting at the top from said two shells 9 and 9', at the bottom having a threaded cylindrical extension 113, on which the knurled ring 141 is screwed, holding the decorative closure plate (not shown) and beneath it the cylindrical sleeve 15, the helical driving cable (not shown) leading therefrom. The latter two elements complete the closure for box 3.

Internally, shell 9 has an annular groove 16 concentric with the central square hole 117 externally associated with the cylindrical seating 18 for accommodating the resilient washer l9 and screw 20.

In the threaded extension 13 an axial through hole M is provided as formed by two semicylindrical grooves 21, one in each shell, and two cylindrical seatings 22 displaced to the right of the vertical axis (as seen in FIG. 4) for accommodating, when assembling, the cylindrical pin 23 about which the carrier wire 24) departs from the axis of hole 21. On the opposite side to seatings 22, the extension halves 13 have two millings 25 involving the entire extension up to the box curve; by bringing the two millings together, the passage is provided (FIG. 2) for the driving cable (not shown).

In turn, shell 9 has, in addition to the above-mentioned details, a cylindrical seating 26 coaxial with the central pin 27, the pin 27 being integral with the shell and having a diametrical slit 27 Reference will now be made to FIG. 5 for describing the inner members: the cup drum 28 has a flanged hole 28' for receiving said pin 27, whereby drum 28 is accommodated within seating 26. The carrying cable 2% is coiled over the external periphery of the drum, while internally the outer end of the coil spring 29 is attached, the inner end 29' of said spring being adapted to be inserted into the slit 27' and hence to be secured to pin 27. Disc 30 is adjacent said spring and provided with a pin 31 having acoaxial threaded hole 32. The end portion of said pin is of a square cross section and fits in the square hole 17 in shell 9. The clutch plate 33 is adjacent said disc 30 and adapted for idling movement on pin 31 and has the shape shown in FIG. 4. This clutch plate 33 has three suitably shaped seatings M accommodating the springs 35 and rollers 36 which in their inoperative condition bear tangentially against the inner periphery of the drum. When the drum rotates anticlockwise, the rollers offer no resistance due to the convenient slope of the seating, while when tending to rotate clockwise, the rollers will lock the drum and make it fast with disc 33. Therefore, at the traction step for cable 24 the friction provided by tightening said screw 20 must be overcome. Thus, when so operating, the clutch plate 33 rotates between disc 30 and washer 37, while the resilient washer I9 is also stressed.

The mechanism of box 8 is completed by tube 38 having curved end flanges and which is inserted into the two grooves 21', to facilitate the slidingof cable 24.

The provision is also made for an anchoring member of the helical driving cable and carrying cable, as shown in FIGS. 6 and 7. This member 39 is screwed in a sleeve 15' equivalent to the upper sleeve 15 and, in turn, having at the bottom a coaxial hole 40 for screwing to the electric light pendant or the like and for the passage of the driving cable, said hole mating with the central slot M in the member and connected with a helical toric groove 42 which is necessarily very deep at the connection area with said slot 41 and reducing to zero as it reaches the top by going about the member.

Member 39 also has an axial hole M, the lower end of the carrying cable 24 passing therethrough and being knotted for fastening to the inside of slot 41.

This particular shape for member 39 aids in connecting the conduct cable end, preventing it from coming out of the sleeve.

What is claimed is:

1. An automatic latch device for suspended electric lights, comprising a circular box divided into two mating shells, a hollow cylindrical drum disposed in said box, a coil torsion spring disposed in said drum, one end of said spring being secured to one of said shells, the other end of said spring being secured to said drum, a carrying cable for an electric light wound about said drum and extending from the lower end of said box, a disc having a central pin disposed in said drum next to said spring, a clutch plate disposed in said drum next to said disc on the side opposite said spring and surrounding said pin, said clutch plate having members thereon engageable with the interior of said drum to permit rotation of said drum relative to said clutch plate in one direction and to prevent rotation of said drum relative to said clutch plate in the other direction, a screw extending through the other of said shells and screwthreadedly received within an axial hole in said pin, and a resilient washer between said screw and said other shell whereby upon tightening said screw against the action of said resilient washer, the force is varied which must be exerted in order to unwind the carrying cable.

2. A device as claimed in claim 1, and a pin secured to said one shell and having a diametrical slit therethrough, said one end of said spring being disposed in said slit.

3. A device as claimed in claim 1, and a pin parallel to the axis of said drum and carried between said shells adjacent the lower end of said box, said carrying cable extending from said drum about a portion of the periphery of the last-mentioned pin and then downwardly to a said electric light.

4. A device as claimed in claim 1, said box having a flat upward extension having a central hole therethrough for suspending said box and a threaded hole beside said central hole for receiving a screw to secure together said shells.

5. A device as claimed in claim 1, said box at the bottom having a cylindrical extension externally screw threaded and having an axial hole therethrough for said carrying cable, said shells together defining between them the last-mentioned axial hole.