Physical-variable measuring, adjusting and displaying instrument

The measuring, adjusting and displaying instrument is of the type comprising a front panel and a pair of printed circuit cards, effective to be inserted into a box, said front panel comprising supporting and guiding means effective to support and guide said cards, and through openings provided for receiving driving and displaying elements. The two printed circuit cards or boards have the driving and displaying elements fixed at 90.degree. with respect to the card plane on the front end portion thereof, being bent parallely to said plane in such a position that, upon having inserted the cards into the supporting and guiding means of the front panel, said driving and displaying elements are effective to automatically insert into the provided openings, thereby being visible and accessible by the operator. On the front panel there are provided means for slidingly applying a handle for withdrawing the instrument from its box, in such a way that the handle can be brought to a retracted position as it is not used. The through openings provided for receiving the driving and displaying elements are so arranged and shaped as to permit said elements to be located both horizontally and vertically.

DESCRIPTION 
The present invention generally relates to measuring, adjusting and 
displaying instruments and, more specifically, to instruments of the 
aforesaid type effective to also provide a visual display of the adjusted 
or controlled variable or parameter and of the possible drifts thereof 
from a predetermined value. 
The instruments of this type as used so far and those recently constructed 
comprise, generally, a front panel therewith two printed circuit cards or 
boards are associated, the overall assembly being effective to be 
slidingly inserted into a box. In order to obtain a visual display and a 
control on the front panel it is necessary to provide said front panel 
both with warning lights or marks and driving or controlling elements 
accessible by the operator. In order to provide the front panel with said 
elements, it is necessary to provide for a central supporting element 
between the two printed circuit boards effective to support the 
controlling elements, while allowing for said elements to be connected to 
the terminals or "pins" of the printed circuit board. 
Furthermore, in order to be able of withdrawing from the box the front 
panel and the printed circuit boards coupled thereto, it is necessary to 
provide a handle or the like, projecting from the front panel by such a 
distance as to permit the operator to grip said handle by his fingers. 
Obviously the preceding needs cause the instrument to have a rather complex 
structure, frequently failing of meeting the user requirements. 
In addition, the presence of a handle projecting from the front panel has 
the drawbacks of a greater size of the instrument and possible failures of 
the handle in the case of collisions. 
Another drawback of these known instruments is that it is necessary to 
provide said central supporting element for the displaying and controlling 
elements, with consequent material and time expenses as required for 
making the different electrical connections. 
The task of the present invention is to obviate the drawbacks thereinabove 
cited by providing a measuring, adjusting and displaying instrument which 
is greatly simple and effective and able to met all the requirements of 
the users. 
Within said task, it is a specific object of the invention to provide a 
measuring, adjusting and displaying instrument which is rationally 
designed in such a way as to greatly simplify the structure of said 
instrument. 
Another object of the present invention is to provide a measuring, 
adjusting and displaying instruments so designed and constructed as to 
reduce to a minimum the steps required for assembling and electrically 
connecting said instrument. 
Yet another object of the present invention is to provide a measuring, 
adjusting and displaying device which is of great operative reliability. 
The thereinabove task and objects, as well as other objects which will 
become more apparent thereinafter, are achieved by a measuring, adjusting 
and displaying device, according to the invention, of the type comprising 
a front panel and a pair of printed circuit boards or cards, characterized 
in that said front panel is provided with supporting and guiding means 
effective to support and guide said boards, and through openings provided 
for receiving controlling and displaying elements, said printed circuit 
boards having the controlling and displaying elements fixed at 90.degree. 
with respect to said said board plane on the front end portion thereof and 
bent parallely to said plane at such a position that, upon having inserted 
said boards into said supporting and guiding means of said front panel, 
said controlling and displaying elements are able of automatically insert 
into said provided openings thereby being visible and accessible by an 
operator. 
According to an aspect of the present invention, on said front panel there 
are provided means for slidingly applying a handle for withdrawing the 
instrument from its box, said handle being effective to be brought to a 
retracted position, as it is not used, thereby obviating the drawback of a 
failure due to a possible collision, and of a great size for said front 
panel. 
According to another aspect of the present invention, said through openings 
provided for receiving said controlling and displaying elements are so 
arranged and shaped as to allow for said elements to be located both 
horizontally and vertically.

FIGS. 1, 2, 3 and 4 show the front panel of a temperature adjusting 
instrument or device, according to the present invention. As shown in 
these figures, the instrument comprises a frame, overally indicated at 1, 
of rectangular shape and having at the rear portion thereof a pair of 
upper arms 2 and a pair of lower arms 3 as projecting perpendicularly 
therefrom. Through its wall there are formed, as shown at the left portion 
of FIG. 1, four holes 4 provided for receiving controlling or driving and 
displaying elements, at the right portion being formed a plurality of 
small holes 5 provided for receiving a corresponding plurality of LED 
diodes. The controlling and displaying elements may consist, for example, 
of warning lights 8, effective to provide a warning indication or signal 
as the temperature is exceedingly passed, and of potentiometer 7 (FIG. 
11). The LED diodes indicated at 6 in FIG. 11 provide a drift parameter 
indicative of the drifting or offsetting from an adjusted value, the 
potentiometer 7 (FIG. 11) being for the calibration adjusting. As it is 
shown in FIG. 11, both said LED diodes 6 and the other elements 7 and 8 
are applied to the printed circuit boards S, S', at 90.degree. with 
respect to the laying plane of said boards; the connection wires are bent 
through 90.degree. in such a way that all the thereinabove cited elements 
lay in a plane which is substantially parallel to said boards plane. The 
arms 2 and 3 of the frame are provided on the outside thereof, at a side, 
with guiding slots 10 for slidingly receiving said printed circuit boards. 
Two vertical slots or grooves 12 (FIG. 4) extend between the two upper arms 
2 and the two lower arms 3 and act to receive therein the front edges of 
said boards S and S'. Upon having inserted said boards S and S' into said 
side slots 10 of said arms 2 and 3 and into the slots 12 between said arms 
2 and 3, said boards are fixed in position by means of screws engaged in 
the holes 11 of said arms. Upon having fixed in position said boards, the 
LED diodes 6 will be precisely inserted into the holes 5 therefor, and the 
controlling and signalling elements 7 and 8 will be precisely inserted 
into the holes 4. 
From the above description the great advantage provided by the invention is 
clearly evident, since it is possible to do away with the central 
supporting element bearing said elements 6, 7 and 8 and the related 
operations for electrically connecting said elements to the boards S and 
S'. 
The frame 1 is furthermore provided with a cross-shaped opening 13, having 
four like arms, provided for receiving or housing a digital setter having 
a rectangular shape with the small side equal to the small side of the 
cross arms and the great side equal to the spacing between the ends of the 
two aligned arms of the cross. Owing to the shape of said opening, said 
setter (not shown) may be located either horizontally or vertically 
thereby providing the possibility of locating the temperature adjusting 
instrument either vertically or horizontally. The lower arm of the opening 
13 is provided with a rectangular notch 14, aligend between the lower arms 
3, each said lower arm being provided, on the inside side thereof, with a 
shallow slot 15, said slots acting as sliding guides for a handle 16. 
The handle 16 is approximately of T-shape, the vertical stem of the T being 
provided with two fins 17, projecting from opposite sides, and having, at 
the ends thereof, two recessed portions 18 effective to be inserted in 
said shallow slots 15 formed in the arms 3. Thus the handle 16 is able of 
sliding in said slots thereby, if it is necessary, the handle can be 
withdrawn and easily gripped by the fingers of a hand in order to pull out 
from the box the frame-printed circuit board assembly. Upon having 
inserted into the box the frame-printed circuit assembly, the handle 16 
may be displaced inwardly, screwing in said handle in order to not project 
from the instrument as this latter is used. 
The instrument also comprises a front plate 19 (FIG. 8) having holes 24 
corresponding to the holes 4 of said frame, holes 25 corresponding to the 
holes 5 of the frame, and a rectangular opening 23 provided for receiving 
said setter and corresponding to the opening defined by two aligned arms 
of the cross-shaped opening 13. At the bottom the plate 19 is provided 
with a rectangular notch 20 effective to enclose the stem of the handle 
16, thereby, as the plate 19 is fixed at the front to the frame 1 and the 
handle is inserted into the notch 14, the handle being prevented from 
disengaging from the thus formed housing. 
FIGS. 5 and 6 show the frame 51 effective to be used in a temperature 
comparing instrument. The frame 51 is of the type of the frame 1 in FIG. 1 
and is provided with two upper arms 52 and two lower arms 53, two holes 54 
each provided for receiving a respective signalling element, guides 60 for 
slidingly receiving the printed circuit cardboards S and S', and holes 61 
for fixing in position said boards. In this case there are provided two 
cross-shaped openings 62 and 63, equal to the opening 13 of the frame 1, 
provided for receiving both horizontally and vertically controlling 
devices, and the notch 64 for receiving the handle 16. For the remaining 
elements, the frame 51 is equal to the frame 1. 
FIGS. 9 and 10 show a frame 71 effective to be used in a digital voltmeter. 
This frame 51 is also of the type illustrated in FIGS. 1 and 5 and is 
provided with two upper arms 72 and two lower arms 73 the guides 80 for 
slidingly inserting the boards S and S' and the holes 81 for fixing into 
position said boards. In this case there are provided a rectangular 
central opening 83 and the notch 84 for receiving the handle 16. With 
respect to the remaining elements, the frame 71 is like the frames 1 and 
51. 
From the above description the great flexibility afforded by the front 
panel according to the invention is self evident, since said front panel 
may be used in a number of different applications and, by varying the 
holes provided on the front plate, the frame may be used in multiple 
different ways thereby providing the possibility of making a great number 
of instruments. 
In addition it has the great advantage of providing a retractable type of 
handle, in all the embodiments thereof. 
It should be particularly pointed out the rationality of the structure of 
the thus obtained instrument, which permits to obviate all of the 
drawbacks of the known instrument of this type. Finally the maintenance of 
the instrument is greatly facilitated thereby helping forward the user. 
In practicing the invention, the used materials, provided that they are 
compatible with the provided use, and the size and specific shapes will be 
any depending on the needs.