Peristaltic pump housing

A housing for a peristaltic pump including a housing body, a roller assembly, a flexible feeder tube, and a cover, the improvement comprising a cylindrical tongue on the housing and a mating groove on the cover adapted to provide a snap-fit releaseable closure.

BACKGROUND OF THE INVENTION 
Peristaltic pumps are known in the art as devices for precision pumping of 
various liquids, mixtures of liquids and solids, etc. The pump involves a 
flexible tube through which the pumped liquid passes. Rollers press the 
flexible tube against an outer wall capturing a precise volume of liquid 
between adjacent rollers which volume is discharged from the pump outlet. 
The servicing and repair of pumps in general usually involves hiring a 
mechanic who requires special tools and know-how to repair the pump. In 
the case of peristaltic pumps which are frequently used in connection with 
residential swimming pools, it has been considered to be highly desirable 
if the pump could be repaired easily by the home owner who had little or 
no mechanical capabilities. 
It is an object of this invention to provide a pump housing wherein the 
cover and the housing are releaseably connected by a snap-fit closure 
means. Still other objects will be apparent from the more detailed 
description which follows. 
BRIEF DESCRIPTION OF THE INVENTION 
This invention relates to a peristaltic pump having a housing, a roller 
assembly, a flexible feeder tube, and a housing cover wherein the 
improvement comprises a tapered tongue member around the outer perimeter 
of said housing adapted to frictionally engage a recess around the outer 
perimeter of said housing cover to close tightly said cover onto said 
housing without need for additional fastening means. 
In specific embodiments the tongue member is a cylindrical projection 
concentric with the housing and projecting outwardly therefrom, the inside 
surface of the tongue being generally cylindrical and parallel to the axis 
of the housing while the outside surface is frustoconical with the larger 
diameter at the free end of the tongue. This combination produces a 
tightly fitting snap-on connection between the housing and the cover.

DETAILED DESCRIPTION OF THE INVENTION 
In the attached drawings there are shown the features of this invention. 
The peristaltic pump includes a housing 15 and a cover 18 enclosing a 
flexible feeder tube 17 and a roller assembly 16. In such a pump the 
roller assembly 16 has three or more rollers between a pair of spaced 
plates 16' which are rotated while pressing tube 17 against the inside 
wall of housing 15. This produces a volume of liquid inside tube 17 
between adjacent rollers of assembly 16 which is forced out of tube 17 as 
the assembly rotates. If roller assembly 16 as seen in FIG. 1 rotates 
counterclockwise, the suction side of the pump is inlet end 27 of tube 17 
and the pressure side of the pump is outlet end 28 of tube 17. Housing 15 
and cover 18 provide an enclosure for roller assembly 16 and anchor points 
for tube 17 near its two ends. Housing 15 is attachable to the housing of 
a driving means, which normally includes an intermittent drive and 
electrical motor (all not shown) by means of slots 29 which cooperate with 
screw heads on the housing of the driving means. The motor shaft 31' 
passes through hole 30 in the bottom of housing 15, is affixed to plates 
16' of roller assembly 16 by means of a flattened portion of the shaft 
31', and is supported in bearing 31 in cover 18. Peristaltic pumps are 
known in the prior art as evidenced by my patent, U.S. Pat. No. 3,756,752 
which shows such driving means and prior art pump. 
In accordance with this invention, cover 18 is removably attachable to 
housing body 15 by a snap-fit attachment which does not require any 
additional fastening devices. This is achieved by the cooperation of a 
tongue 19 on housing 15 with groove 26 on cover 18. Tongue 19 projects 
upwardly in a generally cylindrical configuration from the upper surface 
32 of housing 15. Tongue 19 has an inner surface 20 which is generally 
cylindrical about longitudinal axis 33 of housing 15. Outer surface 21 is 
frustoconical with outer end 34 of tongue 19 being larger in diameter than 
inner end 35. Angle 22 between surface 21 and axis 33 is about 
5.degree.-15.degree., preferably about 10.degree.. Correspondingly, angle 
24 between surface 21 and surface 32 is about 75.degree.-85.degree., 
preferably about 80.degree.. 
Groove 26 in cover 18 is substantially similar in shape to tongue 19 so as 
to fit tightly over tongue 19 with a snap-fit. The inside wall of groove 
26 is cylindrical and the outside wall has a frustoconical surface 
identical to surface 21 of tongue 19. Because of the tight fit between 
tongue 19 and groove 26 there are one or more relief grooves 36 
intersecting groove 26 to permit the free flow of air into and out of 
groove 26 when cover 18 is removed from or attached to housing 15. Grooves 
36 also serve to permit water to flow through in the event water should 
get inside housing 15. It will be seen that outer end 34 of tongue 19 must 
be slightly deformed or compressed in order for groove 26 to receive 
tongue 19 in a mating engagement. This deforming compression results in a 
snap-fit holding cover 18 tightly against housing 15. 
Housing 15 and cover 18 are preferably made of tough plastic such as 
polysulfone, polycarbonate, polyacetal, polyamide, polyvinylchloride, or 
the like, so as to provide the necessary resilience and corrosion 
resistance. Preferably, these plastics are reinforced with fibers of glass 
or other inert materials to provide greater strength properties, and are 
substantially transparent. 
While the invention has been described with respect to certain specific 
embodiments, it will be appreciated that many modifications and changes 
may be made by those skilled in the art without departing from the spirit 
of the invention. It is intended, therefore, by the appended claims to 
cover all such modifications and changes as fall within the true spirit 
and scope of the invention.