BACK PACK PUMP AND SPRAY APPARATUS

RESERVOIR A DOS, AVEC POMPE, TUBE ET BUSE DE VAPORISATION

English Abstract

ABSTRACT OF THE DISCLOSURE

An ambulant liquid spray apparatus includes a
portable liquid storage tank having shoulder carrying straps, a
single-action pump for spraying the contents of the tank
and a flexible hose communicating one end of the pump with
the stored liquid. The pump body defines a cylindrical
chamber in which is slidably disposed a rigid tube having
a free end with a non-telescoping handle extending outwardly
of the chamber for reciprocably displacing the tube within
the chamber and a pair of check valves located within the
tube and pump body direct a unidirectional flow of liquid
through the chamber and tube as the tube is reciprocably
displaced. A packing gland nut sealably closes the other
end of the chamber intermediate the body and tube, the nut
having sidewalls defining an aperture aligned coaxially with
the chamber for slidably guiding the tube, seal means inter-
mediate the sidewalls and tube, and an annular chamber
formed in the sidewalls and defining a lubricant reservoir
intermediate the sidewalls, seal means and tube so that a
liquid lubricant confined to the reservoir lubricates
effectively the portion of the tube slidably guided by the
nut.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:

1. In a liquid spray apparatus having a pump body de-
fining a cylindrical chamber open at both ends, means closing one
end and communicating the chamber with a source of liquid, a
rigid tube slidably disposed within the chamber with a free
end extending outwardly therefrom for reciprocably displacing
the tube within the chamber, and valve means disposed within
the closure means and tube for directing a unidirectional flow
of liquid through the chamber and tube when the tube is recip-
rocably displaced, the improvement comprising a packing gland
nut sealably closing the open end of the chamber intermediate
the body and tube, the nut having sidewalls defining an aperture
aligned coaxially with the chamber for slidably guiding the
tube, seal means intermediate the sidewalls and tube, and an
annular chamber formed in the sidewalls and defining a lubri-
cant reservoir intermediate the sidewalls, seal means and tube
whereby a lubricant confined to the reservoir lubricates the
portion of the tube slidably guided by the nut.
2. An improvement as claimed in Claim 1 wherein the
seal means comprise a pair of longitudinally spaced, resilient
seals.
3. An improvement as claimed in Claim 2, further
comprising a second annular chamber formed in the sidewalls
adjacent the innermost end of the nut for retaining one of the
seals.
4. An improvement as claimed in Claim 3, further
comprising a third annular chamber formed in the sidewalls
adjacent the free end of the nut for retaining the second one
of the seals.




11

5. An improvement as claimed in Claim 4 wherein the pair
of resilient seals comprise O-rings.
6. An improvement as claimed in Claim 5 wherein the O-ring
occupying the second annular chamber has a cross-sectional diameter at
least twice that of the other O-ring.
7. An improvement as claimed in Claim 6, further comprising
a non-telescoping handle mounted on the free end of the tube in coaxial
alignment therewith and in slightly spaced relation with the free end
of the nut.
8. An improvement as claimed in Claim 7, further comprising
first check valve means mounted on the innermost end of the tube and
concentrically therewith, the check valve means having an outside diameter
greater than that of the tube and lesser than that of the pump chamber
to provide substantially linear reciprocation of the tube along the axis
of the chamber.
9. An improvement as claimed in Claim 8 wherein the check
valve means comprises a hexagonal nut having sidewalls threadably
connected to corresponding threads on the tube, an end wall closing the
tube, an aperture with a chamfered inner edge formed centrally in the
end wall, a support member disposed diametrically across the tube adjacent
the free end thereof, a ball adapted to closably engage the chamfered inner
edge and a resilient member intermediate the support member and ball, urging
the ball against the chamfered inner edge and maintaining the check valve
means normally closed and openable upon application to the ball of pressure
exceeding the pressure exerted by the resilient member.
10. An improvement as claimed in Claim 9, further comprising
second check valve means having first sidewalls threadably connected to
corresponding threads on one end of



12


the body, second sidewalls defining a stepped cylindrical aperture through
the second check valve means, the stepped portion being chamfered, a ball
freely disposed in the portion of the aperture having the greater diameter
and adapted to openably close the aperture upon contact between the chamfered
stepped portion and ball, and a resilient, apertured disk overlying the
ball and maintaining the ball captive within the aperture.
11. An improvement as claimed in Claim 10, further comprising
a second aperture formed in the sidewalls for communicating the reservoir
with an external source of lubricant.
12. An improvement as claimed in Claim 11, further comprising
an openable, normally closed lubrication fitting fixedly positioned in the
second aperture.
13. An improvement as claimed in Claim 12 wherein the lubrication
fitting is flush mounted with the external surface of the nut.
14. An improvement as claimed in Claim 13, further comprising
an O-ring disposed concentrically with the tube intermediate the handle
and packing gland nut.
15. An improvement as claimed in Claim 14, further comprising
an O-ring disposed concentrically with the tube intermediate the packing
gland nut and hexagonal nut.
16. A liquid spray apparatus, comprising:
tank means for storing a sprayable liquid;
a pump body defining a cylindrical chamber open at both ends,
including means closing one end and communicating the chamber with the
stored liquid;
a rigid tube slidably disposed within the chamber with a free
end extending outwardly therefrom for reciprocably displacing the tube
within the chamber;




13


valve means disposed within the closure means and
tube for directing a unidirectional flow of liquid through
the chamber and tube when the tube is reciprocably displaced;
and
a packing gland nut sealably closing the open end
of the chamber intermediate the body and tube, the nut having
sidewalls defining an aperture aligned coaxially with the
chamber for slidably guiding the tube, seal means intermediate
the sidewalls and tube, and an annular chamber formed in the
sidewalls and defining a lubricant reservoir intermediate
the sidewalls, seal means and tube whereby a lubricant con-
fined to the reservoir lubricates the portion of the -tube
slidably guided by the nut.
17. Apparatus as claimed in Claim 16 wherein the
seal means comprise a pair of longitudinally spaced
resilient seals.
18. Apparatus as claimed in Claim 17, further com-
prising a second annular chamber formed in the sidewalls
adjacent the innermost end of the nut for retaining one
of the seals.
19. Apparatus as claimed in Claim 18, further com-
prising a third annular chamber formed in the sidewalls
adjacent the free end of the nut for retaining the second
one of the seals.
20. Apparatus as claimed in Claim 19 wherein the
pair of resilient seals comprise O-rings.
21. Apparatus as claimed in Claim 20 wherein the
O-ring occupying the second annular chamber has a cross-
sectional diameter at least twice that of the other O-ring.
22. Apparatus as claimed in Claim 21, further com-
prising a non-telescoping handle mounted on the free end of




14

the tube in coaxial alignment therewith and in slightly
spaced relation with the free end of the nut.
23. Apparatus as claimed in Claim 22, further com-
prising a second aperture formed in the sidewalls for com-
municating the reservoir with an external source of lubricant.
24. Apparatus as claimed in Claim 23, further com-
prising an openable, normally closed lubrication fitting
fixedly positioned in the second aperture.
25. Apparatus as claimed in Claim 24 wherein the
lubrication fitting is flush mounted with the external. sur-
face of the nut.
26. In a liquid spray apparatus having a pump body
defining a cylindrical chamber open at both ends, means
closing one end and communicating the chamber with a source
of liquid, a rigid tube slidably disposed within the chamber
with a free end extending outwardly therefrom for reciprocably
displacing the tube within the chamber, and valve means dis-
posed within the closure means and tube for directing a uni-
directional flow of liquid through the chamber and tube when
the tube is reciprocably displaced, the improvement comprising
a packing gland nut engaging the open end of the pump body in
longitudinally displaceable relation therewith and sealably
closing the open end of the chamber intermediate the body
and tube, the nut having sidewalls defining an aperture
aligned coaxially with the chamber and through which the tube
extends, a pair of resilient seals longitudinally spaced apart
and disposed intermediate the sidewalls and tube for slidably
supporting the tube in spaced relation with the sidewalls,
an annular chamber formed in the sidewalls and defining a
lubricant reservoir intermediate the sidewalls, seals, and






tube, and a second annular chamber formed in the sidewalls
adjacent the innermost end of the nut for retaining one of
the seals in restorably compressible axial relation with the
open end of the body and in restorably expansible radial
relation intermediate the sidewalls and tube to effect an
adjustable seal therebetween as the nut is displaced, whereby
a lubricant admitted to the reservoir is confined therein by
the seals and lubricates the portion of the tube slidably
guided by the nut.
27. An improvement as claimed in Claim 26, further
comprising a third annular chamber formed in the sidewalls
adjacent the free end of the nut for retaining the second
one of the seals.
28. An improvement as claimed in Claim 27 wherein
the pair of resilient seals comprise O-rings.
29. An improvement as claimed in Claim 28 wherein
the O-ring occupying the second annular chamber has a cross-
sectional diameter at least twice that of the other O-ring.
30. An improvement as claimed in Claim 29, further
comprising a non-telescoping handle mounted on the free end
of the tube in coaxial alignment therewith and in slightly
spaced relation with the free end of the nut.
31. An improvement as claimed in Claim 30, further
comprising first check valve means mounted on the innermost
end of the tube and concentrically therewith, the check valve
means having an outside diameter greater than that of the tube
and lesser than that of the pump chamber to provide substan-
tially linear reciprocation of the tube along the axis of
the chamber.
32. An improvement as claimed in Claim 31 wherein the




16

check valve means comprises a hexagonal nut having sidewalls
threadably connected to corresponding threads on the tube, an
end wall closing the tube, an aperture with a chamfered inner
edge formed centrally in the end wall, a support member dis-
posed diametrically across the tube adjacent the free end
thereof, a ball adapted to closably engage the chamfered
inner edge and a resilient member intermediate the support
member and ball, urging the ball against the chamfered inner
edge and maintaining the check valve means normally closed
and openable upon application to the ball of pressure ex-
ceeding the pressure exerted by the resilient member.
33. An improvement as claimed in Claim 32, further
comprising second check valve means having first sidewalls
threadably connected to corresponding threads on one end of
the body, second sidewalls defining a stepped cylindrical
aperture through the second check valve means, the stepped
portion being chamfered, a ball freely disposed in the portion
of the aperture having the greater diameter and adapted to
openably close the aperture upon contact between the chamfered
stepped portion and ball, and a resilient, apertured disk
overlying the ball and maintaining the ball captive within
the aperture.
34. An improvement as claimed in Claim 33, further
comprising a second aperture formed in the sidewalls for
communicating the reservoir with an external source of lubricant.
35. An improvement as claimed in Claim 34, further
comprising an openable, normally closed lubrication fitting
fixedly positioned in the second aperture.
36. An improvement as claimed in Claim 35 wherein
the lubrication fitting is flush mounted with the external,
surface of the nut.




17

37. An improvement as claimed in Claim 36, further
comprising an O-ring disposed concentrically with the tube
intermediate the handle and packing gland nut.
38. An improvement as claimed In Claim 37, further
comprising an O-ring disposed concentrically with the tube
intermediate the packing gland nut and hexagonal nut.
39. A liquid spray apparatus, comprising:
tank means for storing a sprayable liquid;
a pump body defining a cylindrical chamber open at
both ends, including means closing one end and communicating
the chamber with the stored liquid;
a rigid tube slidably disposed within the chamber
with a free end extending outwardly therefrom for reciprocably
displacing the tube within the chamber;
valve means disposed within the closure means and
tube for directing a unidirectional flow of liquid through
the chamber and tube when the tube is reciprocably displaced;
and
a packing gland nut engaging the open end of the pump
body in longitudinally displaceable relation therewith and
sealably closing the open end of the chamber intermediate
the body and tube, the nut having sidewalls defining an aperture
aligned coaxially with the chamber and through which the tube
extends, a pair of resilient seals longitudinally spaced apart
and disposed intermediate the sidewalls and tube for slidably
supporting the tube in spaced relation with the sidewalls,
an annular chamber formed in the sidewalls and defining a
lubricant reservoir intermediate the sidewalls, seals, and
tube, and a second annular chamber formed in the sidewalls
adjacent the innermost end of the nut for retaining one of
the seals in restorably compressible axial relation with the



18


open end of the body and in restorably expansible radial
relation intermediate the sidewalls and tube to effect an
adjustable seal therebetween as the nut is displaced, whereby
a lubricant admitted to the reservoir is confined therein by
the seals and lubricates the portion of the tube slidably
guided by the nut.
40. Apparatus as claimed in Claim 39, further com-
prising a third annular chamber formed in the sidewalls
adjacent the free end of the nut: for retaining the second
one of the seals.
41. Apparatus as claimed in Claim 40 wherein the pair
of resilient seals comprise O-rings.
42. Apparatus as claimed in Claim 41 wherein the
O-ring occupying the second annular chamber has a cross-
sectional diameter at least twice that of the other O-ring.
43. Apparatus as claimed in Claim 42, further com-
prising a non-telescoping handle mounted on the free end of
the tube in coaxial alignment therewith and in slightly
spaced relation with the free end of the nut.
44. Apparatus as claimed in Claim 43, further com-
prising a second aperture formed in the sidewalls for com-
municating the reservoir with an external source of lubricant.
45. Apparatus as claimed in Claim 44, further com-
prising an openable, normally closed lubrication fitting
fixedly positioned in the second aperture.
46. Apparatus as claimed in Claim 45 wherein the
lubrication fitting is flush mounted with the external
surface of the nut.




19

Description

8~

ACKGROUND OE Ti~E INVENTION

The presen-t invention relates to liquid spray
appara-tus and more partieuiarly to a back paek form oE such
apparatus and to an improved single-aetion spray pump used
therewi-th.
An ambulant liquid spraying pump and supply tank,
-cor~nonly referred to as a b~ck paek pu~lp, usu~lly eomprises
a separate, liquid storage tank that is shaped so as to be
eomfortably carried on the baek and shoulders of an :Lndi-
vidual. In this regard, shoulder s-traps are prov:ided by
means of ~hich the tank may be earried in the manner oE a
conventional back paek.
A single-action pump eommunieating with the interior
of the tank by means of a flexible hose provides the means
neeessary for pumping and ejeeting either a solid stream of
liquid or a spray depending upon the form of nozzle employed.
[n its usual conforrnation, the pump eornprises a body haviny a
cylindrieal pump ehamber in which there is reeiprocahly dis-
posed a pistonand eonneeting rod in the Eorm Oe a rlgid -tube.
A cheek valve assembly disposed within eornmon ends of the
cylinder and tube is responsive to fluid pressures generated
during reeiprocation of the tube, resulting in a pressure
buildup and eoneomittant movement of the water unidirectionally
throu~h the ehamber and tube forejection at the nozzle.
Applieations in whi~h such ~umps are employed in-
clude domestic use as garden sprayers that are generally sub-

-jected to harsh operating eonditions as a result o-f corrosive
and toxie pes-tieides and herbieides. A eommon prohlem ex-
perienced wi-th known back pac~ pumps are leaks -that frequen-tly

develop a-t the packiny gland oE the pump as a rèsul-t of wear

.`', ~

-- 1 --

from insufficien-t lubrication and physical disE~lacemen-t of
packing gland sealing material which may comprise compressed
fibers impregnated with graphi-te and one or more petroleum
based lubrican-ts.
A more important use for back pack pumps is in
fiyhting forest Eires or brush fires. Under these circum-
stances operatiTIcJ condi-tions are normally severe and may even
be worsened by using locally available cold sur-face water as
a fire extinc~llishant. Continued loncJ and hard use coupled
with low temperatures :induced by the cold water generally
leads to lnefEicien-t opera-tion oE the pump as a result of
increased sliding Eric-tion resulting from redueed effective-
ness of petroleum luhricants, partieularly of the solici form.
Ineffec-tive luhrica-tion also results in early failure of
paeking glands causing lea]~age at the paeking gland nut and
overall reduced efficiency of the pump. Under the harrowing
conditions of fire fighting, i-t is understandable how lubrl-
cation requiremen-ts would be ignored thereby causing genera:Lly

poor operating performance of pumps and inevitably, early
Eailure.

Pumps having telescoping-type handles are Ereq~lent:Ly
employed and ]ead to the problem of finger pinching which can
be so severe as to incapacitate a fire fighter. This problem
occurs when, through inat-tention, or distraction, an operator
allows a finger or some portion of his hand on the pump handle
to slide between -the handle and pump body. Since the tele-
scoping handle overlaps the body of the pump to some degree,
the finger or o-ther portion of the operator's hand will be

pinched on a compression stroke.



~ `


:,.................................. .

~9~ 7

SUMMARY OF 'l'ilE INVENT:[ON
: A most significant provision of the presen-t in-
vention is an improved single-action pump havincJ a packing
gland nut that includes a luhricant reservoir.
Ano-ther provision of the invention is a packing
gland nu-t in which the reservoir is adapted to retain liquid
lubricants for e:~fectively lubricating the pump irrespec-tive
of o~eratLIly lelnl~eratures.
Still another provision of the invention isa packing
glarld nut having a longer service life and a reduced -tendency
to leak.
Still another provision of the invention is a single-
ac-tion pump having a non-telescoping type of handle -to avoid
finger pinching.
Ye-t another provision of the invention is a back
pack pump that is simple in cons-truction and correspondingly
simple to fabricate.
The problems associated with back pack pumps of -the
prior art may be substantially overcome and the ~oregoing
provisions achieved by recourse to my invention which com-
prises an improvement in a liquid sp:ray appara-tus haviny a
pump body defininy a cylindri.cal chamber open at bo-th ends,
means closing one end and communicating the chamber with a
source of liquid, a rigid tube slidably disposed within -the
chamber with a free end extendi~y outwardly therefrom for
. reciprocably displacing the.tube within the chamber, and
: valve means disposed within the closure means and -tube for
directing a unidirectional flow of liquid through the chamber
and tube when the tube is reciprocably displaced. The improve-
- 30 men-t comprises a pac}~ing gland nut sealably ¢losing the open

z7
end of the chamber intermediate -the bGdy and tube, the nu-t
having sidewalls defining an aper-ture aligned coaxially wi-th
the chamber for slidably guiding the tube, seals means inter
mediate the sidewalls and tube, and an annular chamber
fo~ned in the sidewalls and defining a lubricant reservoir
in-termediate the sidewalls, seal means and tube ~hereby a
lubricant confined to the reservoir lubricates the portion
of the tube slidably guided by the nut.



DESCRIPTION OF TEIE DRAWINGS

l`he invention will now be more par-ticularly described
with reference to an embodiment thereof shown, by way of
example, in the accompan~7ing drawings in which:
Fig. 1 is a perspective view of a back pack pump
embodying the features of the present invention;
Fig. 2 is a plan view of a single-action pump in
accordance with the present invention wi-th portions broken
away to show the internal structure thereof;
Fig. 3 is a longitudinal sectional view -taken along
the lines 3-3 of -the pump in Fig. 2;
Fig. 4 is a longitudinal sectional view -taken along
the lines 4-4 of the pump in Fig. 2;
ig. 5 is a cross-sectional view taken along -the
lines 5-5 in Fig. 4; and
`~ Fig. 6 is an end view of an in-ternal member of the
pump in Fig. 2. ~
~` .
DESCRIPTION OF THE I~LUSTP~TED EM~ODIMENTS


A back pack pump 10 is illustrated in Fig. 1 and
embodies the best mode contemplated by the inven-tor for
carrying out the invention hereinbelow described. It will




_ 4
. ~

~69BZ7
be observed -that -the pump 10 comp~ises a source o~ uid
in the form of a conventionally-shaped i.e., a cross-sectlon
having a kidney shape, tank 11 that is particularly adapted
to be carried upon the back and $houlders of an individual
by an arrangement of shoulder s-traps 12 -that are swivelably
' connected in a known manner -to the tank 11 by means of
- connectors 13 as sllown. Ili~uid to be stored in the tank 11
enters by way of an inlet 14 -that is defined by a short,
upstanding cylindrical sidewall 15 carryin~ threads on the
outer surface thereof which are engageable by corresponding
threads in a known form of closure cap 16 having a central
vent aper-ture 17.
~ single-action pump 20 is shown carried across the
uppermos-t end of the pump 10 by means of a combined pump
holder and carrying handle 21, fastened to the uppermost end
of ~he pump 10 by means of machine screws 22 set in the side-
walls of the tank 11. Resilient spring fingers 23 are curved
-to grip the pump 20 and to hold it firmly against -the handle
21. This combination provides a comfortable carryiny handle
wi-th increased streng-th to resist bending when carryiny a
fully laden tank 11.
The pump 20 communicates ~ith the contents of the
-tank 11 by way of a resilient hose 24, one end of the hose
being clamped -to a bottom spigot 25 by means of a spring
clip 26 and the other end of,the hose being similarly con-

, nected to one end of the pu~p 20.
~ hollow eyelet 27 fits within the aper-ture 17 and
is fastened to one end of a chain 2,8 to prevent loss of the
cap. The free end of -the chain is shown anchored to the
handle 21.




- 5 --

A larger, more detailed view of the pump 20
appears in Fig. 2 with portions broken away to show the
interior s-tructure thereof including a pump body 30 which
'- defines a cylindrical pump chamber 31 that is open ~t hoth
ends thereof. In its assembled Eorm, however, both open
ends are closed. As shown in Figs. 2 and 3, one end is
closed by a packing gland nut 32 that is threadably connected
to the body 30. The other end is closed by means of a check
valve assembly 33 having a spigot 34 -to which is clamped the
hose 24.
Slidably disposed within the chamber 31 is a piston
and rod assembly shown as a rigid tube 35 ~hich, it will be
: understood, is coaxially disposed wi-th the long axis of the
chamber 31. A free end extending outwardly from the chamber
has mounted thereon a non-telescoping handle 36 by means of
which the tube 35 may be reciprocably displaced within the
chamber .
Although not shown in detail, it will be understood
that the handle 36 is held in fixed relation to the free end
of the tube 35 by means of a washer 37 that is affixed to the
.
-tube 35, such as by brazing, and a hexagonal nut 38 that ls
threadably connected to correspondiny threads 39. A threaded
portion 40 outstanding from the nut 38 is adapted to engage
corresponding threads of a spray nozzle 41 that is held cap-
tive to the handle assembly ,by means of a sliding ring 42
connected by a chain 43 to an'anchoring washer 44posi-tioned
in-termediate the nut 38 and the handle 36. A resilient
washer 45 is positioned intermediate the nozzle 41 and -the
nut 38 and acts as a seal to prevent leak$ therebe-tween.
r 30 Pinching of fingers is substantially elimina-ted

~L~6~
since -there is no overlap he-tween -the handle 36 and the
nu-t 32~ Moreover, by virtue of the curved surfaces inter-
facing the handle and nut, -there is a -tendency to push a
finger out of -the way rather than pinching therebetween.
Tllis particular feature of the embodiment illus-tra-ted is
further enhanced by an O-ring ~6 that is positioned coaxially
with -the tube 35 and intermediate -the nu-t 32 and washer 37.
The main func-tion of the o ring ~6, however, is to ac-t as a
resilient bufEer between the nut and washer to reduce noise
and increase service life by absorbing -the impac-t between the
nu-t and washer during pumping opera-tions.
The innermost end of the tube 35 i5 clearly illustratecl
in a sectional view in Fig. 4 which shows the end to be
threaded and connected thereby with corresponding threads 47
lnside a he~agonal nut shown as a hollow p'iston 50. Referenceto
~iCJS. ~ and 6 reveals tha-t the pis-ton 50 has a closed end that
includes a central aperture 51. It will be understood -that
the outside diameter oE -the pis-ton 50 is greater than thak of
the tube 35 and lesser than that of the chamber 31 so as to
provide subs-tantially linear reciprocation of the -tube along
' -the long axis of the chamber.
Loca-ted within the piston 50 is a firs-t checlc valve
52 that comprises a ball valve 53 held ~ieldably against a
i chamfered inner edge 54 of the aperture 51 by means of a
'~ helical re-taining spring 55 that'is positionedbetween the
ball valve and a support member~56. The'member 56 traverses
- the sidewalls of the tube 35 adjacent -the free end there-
'~ of and is fi~ed in posi-tion by means of brazing, soldering and
- the like. An O-ring 57 is shown mounted concen-trically with
-the tube 35 and functions as a shoc]c absorber in a manner

~l69827
simllar to the O-ring 46.
A longitudinal sectional view of ~,he nut 32 is
illustrated in Fig. 3 and shows sidewalls 58 that defi.ne an
aperture which :is aligned coaxia~ly with the chambex 31 and
through which the tube 35 extends. Seal means are provided
in the form of a pair of resilient O-rings 60 and 61, the
O-ring 60 being substantially larger in cross-sectional
diameter than the O-ring 61 so as to provide sufficient lateral
support. This ensures that the exterior surface of the tube 35
.1(1 engages in slidable contact only the O-rings 60 and 61 and does
not stri.ke the sidewalls 58. Contact therebetween cou:ld scratch
the tube 35 which could lead to an imper~ect seal and earl~
failure of the O-rings 60 and 61.
. It will be observed that the O-rings 60 and 61 are
~ held captive withi.n respective annular cha.mbers 62 and 63 that
~ prevent accidental displac~mentof the O-ri.ngs as a result of
-Erictional contact with the tube 35. It will be understood
; from Fig. 3 that the nut 32 is longitudinally displaceable along
the threaded portion of the body 30 such that when tightened
~ 20 thereon the O--ring 60 is restorably compressed in axial re-

.~ lation with the open end of the body 30. As a consequence of
such compression, the O-ring 60 is restorably expansible in a
rad-ial direction intermed.iate the sidewalls 58 and the tube 35
.: to ef:Eect an adjus-table seal therebetween as the nut 32 is
either tightened or loosened. Of particular significance is
a third annular chamber 64 formed in the sidewalls 58 of the
` nut 32 intermediate the O-rings 60 and 61. The chamber 64
defines a lubricant reservoir that is well adapted to confine
liquid lubricants in order to adequately lubricate the portion
of the tube 35 that is slidably guided by the nut 32. A




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~698Z7
s~itable lu~rican-t is admitted to the chamber 64 by means
o,f a lubrication fitting 65 that is flush mounted with the
~xterna~. surface of the nut and which communicates the
reservoir, defined by the chamber 64 and the O-rings 60 and
61 i.n slidable relation with the tube 35~ with an externa~
source of lubricant (not shown).
The other end of the body 30 is c:Losed by the check
valve assembly 33 as may.be best seen in a longitudinal
sectional view thereof in Fig. 4 and a cross-sectional view
in Fig. 5. The physical confo.rmation of the assembly 33 :is
~ha-t of a screw cap having first sidewalls threadably con-
nected to corresponding threads on one end of the body 30 and
second sidewalls defining a stepped cylindri.cal aperture 70
wlth a cha~fered stepped portion 72. A ball valve 71 is freely
disposed in the portion of the aperture having the greater
diameter and is adapted to openabl.y close the aperture upon
contact with the chamfered stepped portion 72. A resilient,
apertured disk 73 is positiorled between the free ends of the
body 30 and the assembly 33, its function being to hold the
ball valve 71 captive and, by flexing into the chamber 31,
to provide a less constricted passageway for fluid flow from
the tank ll into the pump 20. In this regard, it will be seen
that on the compression stroke of the tube 35 the ball valve
71 is seated against the chamfered edge 72, thus sealiny the
aperture 70. Concurrently, the ball valve 53 unseat6 and
admits liquid from bhe chamber 31 into the interior of the
tube 35, the pressurized contents thereby being ~orcibly
e~ected through the spray nozzle 41. Conversely, on the draw
stroke, a suction pressure is created ~y the withdrawn tube
35 such that the disk 73 flexes slightly into the chamber 31.



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~L6i9~327
Concllrrently, the ball :icllve 71 abuts a centra~ portior o r-
the disk 73 and incoming liquid flows around the ball va.'.-e
71 and out through apertures 74 to at Least partially .fi.L
the chamber 31. On the compression stroke, tne liquid is
ejected thro~ugh the nozzle 41 and the pumplng cycle is
repeatecl.
It will be apparen-t to those skilled in the art
that the preceding description of an embodimen-t oE t.he in-
venti.on may be varied to meet particular speciali.zed. require-

-I ments without departing from the true spirit and scope of
the invention disclosed. The embodiment described is there-
fore not to be taken as indicative of the limits of the in-
vention but rather as an exemplary structure thereo.f whi.ch
is defined by the claims appended here;to.




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