Pneumatic circuit arrangement

A pneumatic control for cyclic successive activation of a plurality of pressure fluid consumers and comprising a series of control modules abutting each other in side by side relation for controlling activation of respective ones of the consumers. Each control module comprises a logic plate containing an AND gate and an OR gate and supporting a bistable impulse valve. Each control module further includes a connection plate having connecting openings in its front and rear sides for communication between adjacent modules and means for connecting to the associated consumer. An intermediate seal plate interposed between the connection plate and logic plate has channels therethrough connecting the gates and bistable valve on the logic plate with the connecting openings and connecting means in the connection plate in a manner determined by the pattern of such channels in such intermediate seal plate. The end, or last, control module in the series has an intermediate seal plate differing in the arrangement of its connecting channels from the intermediate seal plates of the preceding control modules to assist in starting a new operating cycle of the plurality of control modules and their associated consumers.

The present invention relates to a pneumatic circuit arrangement, in 
particular in the form of a cyclic control, with logical circuit elements 
such as pulse stages containing AND gates, OR gates or the like, memories 
and/or the like. 
A circuit arrangement of this kind has been made known in the German 
Offenlegungsschrift No. 2,149,189. This known circuit arrangement is 
generally built up separately for a specific function and connected 
together separately. This is relatively complicated and thus expensive not 
only in the case of designing a new control arrangement, but also in the 
case of one or several elements becoming defective in an existing control 
arrangement. 
One object of the present invention is to produce a pneumatic circuit 
arrangement of the type described at the outset, said arrangement 
consisting of individual modules which can be easily exchanged and which 
can be connected together in practically any quantities in order to obtain 
a specific control. 
According to the present invention, this object is solved in that each 
pulse stage is designed as a module composed of a logic plate in which the 
logic elements are integrated, a connection plate with supply lines, that 
enable the logic plates to be connected to each other and to output and 
input modules provided with external pneumatic connections, and a standard 
type of impulse valve which has a memory function, and in that one 
connection plate, one logic plate, and one memory are placed in 
pressure-tight fashion one above the other in each pulse module. 
By integrating the logic elements in the logic plate, it is possible to 
rapidly exchange without much effort the entire logic plate if defects or 
some kind of malfunction should occur. Since the separate plates are only 
placed one on top of the other, it is possible furthermore to effect the 
exchange without undoing tubing or similar connecting elements. Because 
the memory and logic plate can be exchanged individually, maintenance of 
the circuit arrangement according to the present invention is simple and 
cheap; furthermore, this arrangement can be extended as desired. 
In a preferred embodiment of the present invention, a seal is situated 
between the connection plate and the logic plate in such a manner that it 
can be replaced and whose recesses determine the internal circuit of the 
pulse module. In this way it is possible, for example, to obtain two kinds 
of circuit within the pulse module with one and the same logic plate and 
the connection plate located beneath it. Exchanging the seal for another 
is especially advantageous for the pulse module of the last stage if one 
wishes to ensure that the module of the last pulse stage does not 
automatically, or alternatively only by applying an additional impulse, 
reset or prime the first stage of the cyclic control. It is thus in 
particular possible to provide the pulse module with a repetition inhibit 
function by simply exchanging the seal. 
In another preferred embodiment of the present invention, the connection 
plates and/or the input and output plates can be joined together by means 
of connector plugs which can be pressure-tightly plugged into the mutually 
aligned ends of the supply line sections. Both assembly and replacement of 
individual parts is thus made considerably simpler, and furthermore this 
is also a very cheap and distinctive means of connecting the separate 
supply line sections.

The circuit arrangement according to the present invention and shown in the 
drawing is a pneumatic cyclic control 11 which consists of several pulse 
stages each of which is constructed as a module 12, and also an end pulse 
stage constructed as a module 13 and one input and one output module 14 
and 15 respectively. A cyclic control 11 of this kind, which can be as 
long or can be expanded as desired, is used for timed or sequential 
triggering of various pneumatic operating units, or pressure-medium 
consumers which are not however described here, in one or several machines 
or the like and which perform operational steps in specific time sequence. 
As it will still be shown, the cyclic control 11 is constructed in such a 
way that a particular operating step can be executed only if the preceding 
operating step has been completed. In the described embodiment, this 
operating cycle can however only then be repeated if the last operating 
step has been completed and if repetition of the operating cycle is 
desired, and this is accomplished for example by the machine operator 
starting the new operating cycle by hand. 
Each module 12, 13 consists of a connection plate 16, a logic plate 17, and 
a memory 18, these elements being arranged one above the other or placed 
on top of each other and pressure-tightly joined together. To produce 
module 12 for the front pulse stages a seal 21 (or connecting plate of 
sealing material) is located between the connection plate 16 and the logic 
plate 17, whereas to produce module 13 for the end pulse stage another 
seal (or connecting plate of sealing material) 22 is inserted between 
connection plate 16 and logic plate 17. Seals 21, 22 which, as will still 
be demonstrated with reference to FIGS. 3 and 4, are provided with 
different recesses, result in a differing internal linkage between logic 
plate 17 and connection plate 16. 
In this embodiment, the connection plates 16 have four parallel irregularly 
spaced holes 26 to 29 each of which forms a section of the lines S, Z, P 
and Y which have yet to be described. Of these holes, the holes 26 and 28 
penetrate the entire width of the connection plate 16, whereas the holes 
27 and 29 are two blind holes going out from their two sides for the 
incoming part Z.sub.1 and Y.sub.1 and the outgoing part Z.sub.2 and 
Y.sub.2 of the relevant lines. The input and output modules 14 and 15 are 
made as plates which are provided with blind holes 31 to 34 which emanate 
from that longitudinal side which faces the holes 26 to 29 of the 
connection plates 16. The blind holes 31 to 34 join into holes travelling 
vertically downwards and not shown in the drawings, said holes being in 
line with connecting nipples for joining to external lines. Symmetrically 
shaped, hollow cylindrical connector plugs 36 are pressure-tightly 
inserted into the holes 26 to 29 and 31 to 34 of the input, and output and 
connection plates 14, 15, 16 such that the lines S, P and the line 
sections Z.sub.1, Z.sub.2 and Y.sub.1, Y.sub.2 are formed by the holes. 
Furthermore, the input, output and connection plates 14, 15, 16 are so 
constructed that they can be attached to a mounting frame 37 which 
consists of two parallel longitudinal and several transverse frame members 
38, 39. The length of the longitudinal frame members 38 depends here on 
the number of pulse stages 12, 13 which are to be used. 
As can be seen from FIGS. 3 and 4, which show a section in the region of 
the outgoing line parts Z.sub.2 and Y.sub.2, the throughholes 26 and 28 
and the blind holes 27 and 29 are each joined with one of the holes 41 in 
a specific plane vertical to them, said holes emanating from the top side 
42 of the connection plate 16 which is adjoined by seal 21 or 22 and logic 
plate 17. Furthermore, the connection plate 16 has another two 
throughholes 43, 44 which are parallel to the holes 41 and pass through 
connection nipples 46 on the underside and thus form part of an operating 
line A and an acknowledgement signal line X. 
The logic plate 17 has two pneumatic valves as integrated components, the 
one being constructed as an AND gate 47 and the other as an OR gate 48. 
Channels 49 and channels 50 are provided in the logic plate 17, and these 
are assigned to the AND gate 47 and to the OR gate 48 and extend to the 
upper side 51 or to the underside 52 of the logic plate 17 depending on 
which function the channels 53, 54 have to fulfill. In addition, the logic 
plate 17 has two parallel channels passing through from the underside 52 
to the upper side 51, of which the described channels 53, 54 join the 
pressure line P in the connection plate 16 with one input of the memory 
18, or the operating line A in the connection plate 16 with one output of 
the memory 18, through seal 21 or 22 respectively. The memory 18 is a 
standard type of air impulse valve which, in this embodiment, has five 
inputs and can assume two switching positions. The memory valve 18 which 
is attached to the upper side 51 of the logic plate 17 is provided with 
connecting holes or channels which are not described here and which are 
connected to the corresponding channels in logic plate 17. All connections 
between memory valve 18 and logic elements 47, 48 are shown fully in FIG. 
2. 
As can be seen from FIG. 3, in the module 12 seal 21 is provided with holes 
and slots 58, 59 in such a way that the reset line S is connected to the 
pressure line 50' and the outgoing section Z.sub.2 of logic connection 
line Z is connected to the other pressure line 50" of the OR gate 48. The 
output 50'" of the OR gate 48 leads to one control input of the memory 
valve 18. Channel 53 of the pressure line P leads to a memory valve input 
and channel 54 of the operating line A leads to a memory valve output, and 
in one switching position of the memory valve 18 such input and output are 
connected together. The section Y.sub.2 of the logic connection line Y 
leading to the next stage, in other words the outgoing section, is 
connected to the channel 49' which leads to an output of the AND gate 47, 
while its input leads through a channel 49" in a way which is not 
described, or within the valve 18, to the operating position A. Here too, 
input and output are connected together in one switching position of the 
AND gate 47. One control input of the AND gate 47 leads through channel 
49'" to the acknowledgement signal line X, whereas the reset input is 
formed by a spring 61 in which position the logic connection line section 
Y.sub.2 is separated from the operating line A. The sections Z.sub.1, 
Y.sub.1 of the logic connection lines Z and Y respectively coming from the 
preceding pulse stage 12 are connected to the operating line A through a 
curved slot in the seal 21 or they are connected to the memory valve 18 
through a seal hole and a throughhole in the logic plate 12. 
In module 13 for the end pulse stage, as shown in FIG. 4, only the seal has 
been exchanged when compared with module 12 in FIG. 3. Seal 22 is provided 
with holes and slots 58', 59' in such a manner that the incoming section 
Y.sub.1 of logic connection line Y is connected with one input and the 
reset line S is connected with the other input of the OR gate 48 whose 
output also leads to the memory valve 18 in a manner which is not 
described here, although to the other control input as shown in FIG. 2. 
Furthermore, the outgoing section Z.sub.2 of the logic connection line is 
connected to the one control input of the memory valve 18 through a 
throughhole 60 shown by dotted lines. With respect to the pressure line P, 
the acknowledgement signal line X, the operating line A, the outgoing 
section Y.sub.2 and the incoming section Z.sub.1 of the respective linkage 
connection line, seal 22 is constructed in the same fashion as in FIG. 3, 
i.e. like the seal 21. 
As can be seen in FIGS. 2 and 3, the operating line A leads through the AND 
gate 47 to the upper side 51 of the logic plate 17 to the aperture of 
which a pressure indicating device 56 is provided. With this pressure 
gauge 56, one can monitor to ensure that the pressure exists or has built 
up in each pulse stage 12, 13 and in the proper sequence. The air impulse 
valve 18 has furthermore a manual control which is not described here, and 
this allows the status of the memory 18 to be determined. 
Essentially, the cyclic control 11 according to the present invention 
functions as follows: The memory valve 18 is set through the logic 
connection line Y whenever the AND gate 47 of the preceding pulse stage 
delivers an output signal. This setting signal at memory 18 of one pulse 
stage 12 first initiates the control signal in the operating line A 
through the operating unit concerned for the next pulse stage 12, secondly 
resets the memory 18 of the one pulse stage 12 through the associated OR 
gate 48, thirdly enables the AND gate 47 of said next pulse stage 12 or 
13, and fourthly visually indicates the operating signal on the pressure 
gauge 56. If completion of this first switching step, or execution of the 
stroke or similar of the operating unit concerned is acknowledged by a 
signal occurring in the acknowledgement line X, then the AND gate 47 of 
said next pulse stage 12 receives its second input signal after the 
operating signal A, i.e. in this case it receives its control signal X, 
and thus the AND gate 47 is switched and a signal is produced in the 
outgoing logic connection line Y.sub.2. This pulse which passes through 
from pulse stage to pulse stage and which can be dependent on the speed or 
a similar variable of the operating unit concerned passes on up to the end 
pulse stage 13. As already mentioned, this end pulse stage 13 is triggered 
in such a manner that the cyclic control 11 repeats its operating cycle 
only if the operator actuates a pushbutton 57 which is connected in the 
external return line of the logic connection line Y from the end pulse 
stage 13 to the first pulse stage 12. Cancellation of the final pulse 
stage 13 is then effected differently as compared with the first pulse 
stages, that is only through the reset line S with which at the same time 
all other pulse stages are also cancelled. Resetting of the memory 18 of 
the end pulse stage 13 is effected through the logic connection line Z 
coming from the input stage 12. 
Although our invention has been illustrated and described with reference to 
the preferred embodiments thereof, we wish to have it understood that it 
is in no way limited to the details of such embodiments, but is capable of 
numerous modifications within the scope of the appended claims.