COMPACT PNEUMATIC PEDAL ASSEMBLY

Abstract: The pedal assembly comprises a small casing (1), a small-stroke pedal element (2) and a valve body (3;4) either of the 3-or 5-way type,so assembled as to provide a very compact device.

Description: BACKGROUND OF THE INVENTION The present invention relates to an improved pneumatic pedal assembly. As is known pedal driving assemblies are frequently used for small size or micro motors,for example for the dentistry field and goldsmith's art, as well as in washing machines. The valves used for controlling servovalves are however of comparatively great size (from 1/8" to 1/4") or they are paired or pair coupled,that is one pneumatic valve associated with an electric valve. Moreover in prior apparatus of the above mentioned type,a pedal usually controls a remote control switch in turn controlling the driving coil of a servocontrol operating either a cylinder or another cylinder of a two cylinder operating assembly. The document DE-A-31 29 355 discloses a pneumatic pedal assembly having substantially the features of the pre-characterizing portion of the main claim. SUMMARY OF THE INVENTION The present invention sets out to overcome the above mentioned drawbacks, by providing a pedal control assembly bypassing the electric aspect or elements of a control of the above mentioned type and which operates on servocontrol coils or solenoids by pneumatically operating on said servo-control. Within the scope of the above aim,a main object of the present invention is to provide such a pedal assembly which comprises exclusively pneumatic component thereby reducing to a minimum the making cost and maintenance and repairing requirements. Another object of the invention is to provide such a control pedal assembly specifically designed for washing machines. According to one aspect of the present invention,the above aim and objects,as well as yet other objects,which will become more apparent hereinafter, are achieved by a pneumatic pedal assembly, having the features of the characterizing part of the main claim. BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the invention will become more apparent hereinafter from the following description of a preferred embodiment thereof,which is illustrated,by way of an indicative but not limitative example,in the figures of the accompanying drawing,where: figure 1 is a schematic view illustrating a control pedal assembly with the casing mounted on the pedal element and valve body; figures 2 and 3 are cross-sectional views showing a control pedal assembly including a normally closed 3-way valve body and a 5-way valve body with M5 fitting respectively; figures 4 and 5 are front views respectively illustrating a control pedal assembly with a 3-way valve body and protected M5 fitting and a quick coupled 5-way valve body. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the figures of the accompanying drawings,the control pedal assembly according to the present invention comprises a reduced size casing, indicated at the reference number 1,a pedal element 2 and either a 3-way or a 5-way valve body. In the illustrated embodiment 3 of the 3-way valve body,either of the normally opened or normally closed type,and in the embodiment indicated at 4 of 5-way valve,there is included a quick type of fitting, indicated at 5,or a M5 type of fitting indicated at 5'. The control pedal assembly according to the present invention is specifically provided for actuating a pneumatic servo-control in which the operating fluid,for example filtered and lubricated air,efficiently operates through the overall required temperature and pressure range,depending on the preset passage diameter and cross-section. The casing 1 is preferably made of a black galvanized sheet metal,passivated against corrosion, arid in the bottom of said casing there are formed threaded holes 6 for receiving screws for connecting the control pedal assembly to the machine to be controlled. According to a preferred embodiment,the valve body 7 is made of anodized aluminium,whereas the spool member 8 is made of processed brass,the gaskets 9 being of conventional type. It should be apparent that the subject control pedal assembly can be provided with a protective cover 10 (fig.4).

Claims: A pneumatic pedal assembly for controlling small size motors in dentistry apparatus, goldsmith's apparatus, washing machines and the like, comprising a substantially parallelepipedal casing supporting on a major face thereof a depressible pedal (2) of substantially rectangular shape, a pneumatic valve body (7) fixed inside said casing to be directly actuated by said pedal (2), characterized in that said pneumatic valve body (7) is an anodized aluminium valve body fixed to a minor face of said casing (1), to said body (7) there being coupled an extending brass valve spool member (8) to be directly actuated by said pedal (2), and in that fitting means (5, 5') communicating with said valve body (7) are associated with said same minor face of said casing. An assembly according to Claim 1, characterized in that said pneumatic valve body (7) is a 3-way valve body. An assembly according to Claim 1, characterized in that said pneumatic valve body is a 5-way valve body. An assembly according to Claim 1, characterized in that said fitting means (5, 5') comprise a quick type of fitting (5). An assembly according to Claim 1, characterized in that said fitting means (5, 5') comprise a M5 type of fitting.

Inventors: SORBA, RENZO STEELCONTROL S.R.L.
Applicants: STEELCONTROL S.R.L.
Application year: 1989
Main classification: G05G1
IPC codes: G05G1