Hermetically sealed pump

Claim 2

A pump comprising, a cylinder defining a piston chamber, a piston located in said cylinder for reciprocation therein, a fluid manifold associated with said piston cylinder and having suction and discharge ports located in communication with said piston chamber, valve means operatively associated with said ports for simultaneously opening one of said ports and closing the other of said ports in response to the pressure in said piston chamber, means for hermetically sealing said piston chamber on the side of said piston opposite said ports, thereby to prevent loss of fluid in said pump through said piston chamber, and means for reciprocating said piston including a driven eccentric cam and a cam follower operatively connected between said piston and said cam, and means biasing said cam follower into engagement with said cam whereby rotation of said eccentric cam causes reciprocation of said piston in said chamber to alternately produce relatively low and high pressures in said chamber, thereby to draw fluid from said manifold through said suction port into said piston chamber and thence discharge said fluid through said discharge port; said means for hermetically sealing said piston chamber comprising a diaphragm formed of an elastomeric material operatively connected between said cylinder and said piston and having a first side facing said piston chamber and a second side opposite said first side and remote from said piston chamber; said diaphragm having inner and outer edge portions respectively connected to said piston and said cylinder and having a thickness between said inner and outer edge portions which is greater than the thickness of said edge portions thereby to form a bulge in said diaphragm between said edge portions to define a pair of curved rolling surfaces thereon; and means forming a pair of opposed continuously curved surfaces adjacent said second side of said diaphragm in predetermined relation to each other whereby said curved rolling surfaces of the diaphragm roll along said opposed continuously curved surfaces in opposite directions during reciprocation of said piston.

Claim 3

A pump as defined in claim 1 wherein saiD piston includes a piston rod connected to said follower, and said means forming said opposed continuously curved surfaces includes a guide flange having a central bore opening towards said piston and piston chamber, said flange having a peripheral edge portion surrounding said bore, said edge portion being rounded to form one of said continuously curved surfaces, and a generally disk shaped guide member on said piston rod having a peripheral rounded surface forming the other of said continuously curved surfaces.

Claim 4

A pump as defined in claim 2 wherein said diaphragm has a generally toroidal configuration when viewed in plan, said outer edge portion being clamped between said guide flange and said cylinder and said inner edge portion being clamped between said piston and said guide member thereby to form said bulge in said diaphragm between said inner and outer edge portions and form said curved rolling surfaces engaging the continuously curved surfaces of said flange and guide member.

Claim 5

A pump as defined in claim 3 wherein said guide member is positioned to have its curved surface located at a level above the curved surface of said flange when said piston is in its top dead center position and at a level below the curved surface of said flange when said piston is in its bottom dead center position.

Claim 6

A pump as defined in claim 2 wherein said means for biasing said cam follower into engagement with said cam comprises a compression spring operatively connected between said flange and said cam follower.

Claim 7

A pump as defined in claim 2 wherein said valve means includes a flap valve operatively associated with said suction port.

Claim 8

A pump as defined in claim 6 wherein said valve means further includes a check valve operatively associated with said discharge port for opening said discharge port when said flap valve closes said suction port.

Claim 9

A pump as defined in claim 7 including an electric motor having an output shaft, and said eccentric cam comprises an eccentric cam bushing secured to said shaft and a rotary bearing mounted on said cam bushing in engagement with said cam follower.

Claim 10

A pump as defined in claim 1 wherein said diaphragm cooperates with said piston to form a fluid chamber therebetween in said cylinder, and said cylinder has a fluid passage formed therein providing fluid communication between said fluid chamber and said suction port.

Claim 11

The pump as defined in claim 3 wherein said continuously curved surfaces are spaced from each other and the bulge in said diaphragm enters the space between said continuously curved spaces thereby allowing said pump to withstand high pressures.

Claim 12

A pump comprising, an electric motor having a rotary power output shaft, means forming an eccentric rotary cam surface mounted on said shaft, and a piston assembly operatively associated with said eccentric cam surface including a piston cylinder having a piston chamber formed therein, a piston located in said cylinder, having a piston rod and an operatively associated cam follower, a guide flange operatively connected to said cylinder between said cylinder and said cam and having a central bore opening towards said piston and piston chamber, said piston rod extending through said bore and being guided thereby during reciprocation of said piston, a compression spring operatively connected between said flange and said cam follower for biasing said cam follower into engagement with said cam surface whereby said piston is reciprocated during rotation of said cam surface to alternately produce relative low and high pressures in said cylinder, a fluid manifold operatively associated with said cylinder and having independent fluid inlet and outlet ports formed therein, anc communicating with said piston chamber, first valve means operatively associated with said inlet port for opening said inlet port and permitting fluid to flow into said piston chamber during the downward suction stroke of said piston and closing said inlet port on the upward-discharge stroke of said piston, and second valve means operatively associated with said outlet port for closing said outlet port on the downward-suction stroke of said piston, and opening said outlet port on the upward-discharge stroke of said piston, and a generally toroidally-shaped diaphragm formed of an elastomeric material operatively connected between said cylinder and said piston for hermetically sealing said piston chamber to prevent loss of fluid therefrom during operation of said pump; said diaphragm having a first side facing said piston chamber, a second side opposite said first side and remote from said piston chamber, inner and outer edge portions respectively connected to said piston and said cylinder, and a thickness between said inner and outer edge portions which is greater than the thickness of said edge portions, thereby to form a bulge in said diaphragm between said edge portions to define a pair of curved rolling surfaces thereon: said flange bore having a rounded upper peripheral edge portion adjacent said cylinder defining a first continuously curved diaphragm rolling and support surface and said piston rod having a generally disc-shaped guide member adjacent said piston and a rounded peripheral surface defining a second continuously curved diaphragm rolling and support surface; said continuously curved diaphragm rolling and support surfaces respectively engaging said pair of diaphragm curved rolling surfaces to support said diaphragm during reciprocation of said piston, whereby said diaphragm curved rolling surfaces roll along said continuously curved diaphragm rolling and support surfaces of the flange and guide member in opposite directions during reciprocation of the piston.

Claim 13

A pump comprising, an electric motor having a rotary power output shaft, means forming an eccentric rotary cam surface mounted on said shaft, and a piston assembly operatively associated with said eccentric cam surface including a piston cylinder having a piston chamber formed therein, a piston located in said cylinder, having a piston rod and an operatively associated cam follower, a guide flange operatively connected to said cylinder between said cylinder and said cam and having a central bore opening towards said piston and piston chamber, said piston rod extending through said bore and being guided thereby during reciprocation of said piston, a compression spring operatively connected between said flange and said cam follower for biasing said cam follower into engagement with said cam surface whereby said piston is reciprocated during rotation of said cam surface to alternately produce relative low and high pressures in said cylinder, a fluid manifold operatively associated with said cylinder and having independent fluid inlet and outlet ports formed therein, anc communicating with said piston chamber, first valve means operatively associated with said inlet port for opening said inlet port and permitting fluid to flow into said piston chamber during the downward suction stroke of said piston and closing said inlet port on the upward-discharge stroke of said piston, and second valve means operatively associated with said outlet port for closing said outlet port on the downward-suction stroke of said piston, and opening said outlet port on the upward-discharge stroke of said piston, and a generally toroidally-shaped diaphragm formed of an elastomeric material operatively connected between said cylinder and said piston for hermetically sealing said piston chamber to prevent loss of fluid therefrom during operation of said pump; said diaphragm having a first side facing said piston chamber, a second side opposite said first side and remote from said piston chamber, inner and outer edge portions respectively connected to said piston and said cylinder, and a thickness between said inner and outer edge portions which is greater than the thickness of said edge portions, thereby to form a bulge in said diaphragm between said edge portions to define a pair of curved rolling surfaces thereon: said flange bore having a rounded upper peripheral edge portion adjacent said cylinder defining a first continuously curved diaphragm rolling and support surface and said piston rod having a generally disc-shaped guide member adjacent said piston and a rounded peripheral surface defining a second continuously curved diaphragm rolling and support surface; said continuously curved diaphragm rolling and support surfaces respectively engaging said pair of diaphragm curved rolling surfaces to support said diaphragm during reciprocation of said piston, whereby said diaphragm curved rolling surfaces roll along said continuously curved diaphragm rolling and support surfaces of the flange and guide member in opposite directions during reciprocation of the piston.

Claim 14

A pump as defined in claim 11 wherein said disk shaped guide member is located in predetermined relation with respect to said flange thereby to position said second diaphragm rolling and support surface at a level above said first rolling and support surface when said piston is in its top dead center position and at a level below said first diaphragm rolling and support surface when said piston is in its bottom dead center position, whereby said diaphragm rolls along said diaphragm rolling and support surfaces in opposite directions during reciprocation of said piston.

Claim 15

A pump as defined in claim 11 wherein said first valve means comprises a flap valve and said second valve means comprises a spring biased check valve.

Claim 16

A pump as defined in claim 11 wherein said means forming an eccentric rotary cam surface comprises an eccentric cam bushing mounted axially on said output shaft and a rotary bearing mounted on said cam bushing and having an outer annular surface engaged with said cam followers.

Claim 17

A pump as defined in claim 11 wherein said diaphragm cooperates with said piston to form a fluid chamber therebetween in said cylinder, and said cylinder has a fluid passage formed therein providing fluid communication between said fluid chamber and said suction port.