Pneumatic connector

Abstract: A pneumatic connector for use for example between a hoist and a hoist pendant is provided with tapered holes (12) and ferrules (8) to progressively compress and retain interconnecting pneumatic tubing (7) and further provides for assembly of a protective sheath (5). The connector further provides limited free rotation and a quick disconnect face seal accomplished by a single rotating threaded sleeve (10).

Description: This invention relates generally to connectors for pneumatic pressure conveying devices such as hoses and more particularly to a connector for quick connecting various pneumatic devices together as, for example, a remote pneumatic control pendant for an air control valve for a hoist. In the past such connections have been cumbersome, difficult to make and subject to premature failure due to their relative stiffness working the joint upon movement of the pendant control relative to the fixed control valve. GB-A-1 197 447 discloses a pneumatic connector for coupling two flexible hose lengths, the connector including the features of the preamble of claim 1. According to the present invention, there is provided a pneumatic connector for pneumatic pressure tubing according to claim 1. For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a schematic view showing a typical application of a pneumatic connector, Figure 2 is a cross-section of a connector and hose assembly showing a device connection on the left and the present female quick connection device on the right; Figure 3 is a cross-section showing the present male quick connection device on the left and a device connection on the right; Figure 4 is a cross-section showing the assembled quick disconnecter; Figure 5 is a cross-section showing a detail of a terminal end and the tapered ferrules; Figure 6 shows an end view of the female connector showing the orientation of the component lines; and Figure 7 is an end view of the male connector showing the complementary orientation of the component lines. This invention pertains to a connector which provides simple disconnect and recoupling of bundled pneumatic supply and signal lines. A connector of this type is particularly useful for quick connecting various pneumatic devices together in series. A typical application of the present connector is shown in Figure 1 in which a hand held remote pneumatic control station 30 is shown connected to a directional air control valve 40 by means of an air signal and supply line 50. The advantage is that the hand held control station can be quickly disconnected for repair or replacement. A further advantage of this device is that it allows the length of the bundled supply to be increased or reduced by simple addition or subtraction of a tubing bundle of any length having mating connector halves at each end. A significant feature of this coupling is the method for attaching the supply and signal lines to each half of the connector in a manner which allows the maximum number of lines to be accommodated in the smallest possible space. This accomplishment allows the connector to be similar in diametral size to the protective sheath that the bundled supply and signal lines pass through. This is particularly important for hand held control stations since a large and bulky connector would impede free movement by catching on obstructions. A further feature of this device is that a single threaded sleeve is used to connect the two halves of the coupling and also compress the rubber gasket between them to form an airtight seal. Referring to Figures 2 and 3, the connector and tubing bundle is shown in cross-section uncoupled. End fittings 1 allow each half to be connected to its respective device by pins 2 which also allow approximately 180 degrees of rotational freedom. This rotational freedom is particularly advantageous for hand held devices connected by the tubing bundle since it relieves torsional loading caused by the tendency of the tubing bundle to twist when the hand held device is moved to different positions. Standard commercial conduit fittings consisting of a threaded coupling 3 and compression nut 4 are used to connect the protective sheath 5 of the tubing bundle to the swivel end and coupling end of each assembly. The threaded coupling (3) is provided with threads on each end: a thread 21 to engage threads 22 of the compression nut 4 and a thread 23 to engage an internal thread 24 of the terminal 6 or alternatively internal threads 25 of the end fitting 1. Referring to Figure 5, each half of the connector has an identical tubing end terminal 6 to which the internal supply and signal lines are attached. Each terminal is generally cylindrical in shape and formed with an end cap which has a series of radial holes 12 through it to accommodate the required number of supply and signal lines. These holes are sized to allow the tubing 30 to pass through easily and they are counter bored at 11 on the outer face of the terminal to receive tapered retaining ferrules 8. Referring to Figure 4, shown is a view of the connector when assembled. Lines 7 are passed through the terminals 6 until they slightly protrude from the face of the terminal. The hollow bored tapered ferrules 8 are then placed into the end of each line 7 and then simultaneously driven with an impact tool into the counter bores 11 in the terminal. In this manner the lines are driven back flush with the face of the terminal and the ferrules, driven into the end of each line, cause each respective line to expand against the counter bore. Any attempt to pull the line 7 out of the terminal pulls the tapered ferrule 8 further into the counter bore 11 causing it to lock tighter against the step between the counter bore and the through hole. The resulting connection is as strong as the line itself. In the assembled connector, the terminals 6 are tied by alignment pins 9 and pulled together by a sleeve shoulder 17 and acting against a terminal shoulder 18, the threads 16 of the threaded sleeve 10 being in engagement with the external threads 20 on the terminal 6 against a rubber seal gasket 15. The supply and signal lines are colour coded as shown in Figures 6 and 7.

Claims: A pneumatic connector for pneumatic pressure tubing (7), the connector comprising a terminal (6) of generally cylindrical shape provided with an end cap, said end cap having a series of counter bored, radial holes (12) for receiving pneumatic pressure tubing (7) passed through the cylindrical portion of said terminal and disposed in said holes (12), a protective sheath (5) and a hollow bored ferrule (8) disposed within the end of said tubing and within said radial holes (12); characterised in that the ferrule (8) has an outside taper and, on assembly, retains said tubing within said radial holes, which are internally tapered, with increased wedging action between the outside taper of said ferrule and the internal taper of said radial holes (12), said terminal (6) having an internal thread (24) assembled with a threaded coupling (3), and an external thread (20) assembled with a threaded sleeve (10) and said threaded coupling (3) is connected to a compression nut (4) to effect assembly of the protective sheath (5) to provide a protective sheath and tubing assembly. A pneumatic connector according to claim 1, wherein said terminal has a gasket (15) for face sealing of said radial holes (12) upon assembly of two terminals secured in face-to-face relationship by said threaded sleeve. A pneumatic connector according to claim 1 or 2, wherein said end cap is provided with alignment means (9) for fixing the orientation of said radial holes (12) on assembly. A pneumatic connector according to claim 3, wherein said alignment means comprises alignment ends protruding from an end external face of said end cap. A pneumatic connector according to any one of the preceding claims, wherein said protective sheath (5) is terminated in a second compression nut and threaded coupling assembly, which in turn is further terminated in an end fitting (1) provided for attachment to a control means. A pneumatic connector according to claim 5, wherein said end fitting is provided with means for permitting free limited rotation of said end fitting (1) and hence said pneumatic connector assembly relative to said control means. A pneumatic connector according to claim 6, wherein said means for permitting free limited rotation further comprises a pin (2) and slot.

Inventors: SELL LESLIE J, SELL, LESLIE J.
Applicants: INGERSOLL RAND CO, INGERSOLL-RAND COMPANY
Application year: 1996
Main classification: F16L39
IPC codes: F16L39