G. E. GALL 2,407,9923 PUMP Filed Jan. 31, 1944 Y 5 Sheets«Sheet l @naga Sept. >117, 1946.. _ Q_ E GALL PUMP Filed Jan. 3l, 1944 ' _ 2,407,923 ' 3 Sheets-Sheet 3 Patented Sept. 17, 1946 2,407,923 UNITED STATES PATENT OFFICE` 2,407,923 PUMP George E. Gall, Chicago, Ill., assignor to Anker Holth Manufacturing Company, Inc., Chicago, Ill., a corporation of Michigan Application January 31, 1944, Serial No. 520,391 7 Claims. 1 This invention relates to a pump, and more particularly to a hydraulic pump for delivering liquid under pressure. The pump may be used for operating hydraulic cylinders to furnish pow er for various appliances, and can be utilized wherever it is desired to supply hydraulic pres sures. (Cl. 10S-10) 2 The pump body and caps may be formed of cast ings of any suitable metal. 1 ' A drive shaft I4 extends through the structure, being journaled in the bearing I5 in the front cap I I and driven by any suitable source of power such as the electric motor I1 shown in Fig. 1. ‘ Inside the front cap I I, and shown more clear An object of the invention is to provide a pump ly in Fig. 4, is a low pressure pump section A which will deliver liquid at high pressures when which includes the gear I8 mounted on the shaft high pressures are required for the work being 10 I4. Located above and in meshed relation‘with done, and which will develop these high pressures gear I8 is a second gear I9 mounted on shaft 20 without the objectionable pulsations or vibra which has its one end journaled in the bearing 2I tions which are commonlyassociated with such carried in the body I0 and which has'its other operation. ‘ Y end journaled in the bearing 22 carried in the Another object of the invention is to provide front cap I2. « a pump of this character which is capable of A passage 23 leads from an opening ,24 in the developing very high pressures, but which at the top of the pump body Il] to the gears I8 and I9. same time will deliver liquid at a rapid rate dur A second opening 25, which is in the side of the ing periods of operation in which high pressures body Ill, also communicates with the passage 23. are not required, so that an overall operation in 20 One of the openings 24 and 25 may be plugged and volving periods of low pressure operation and pe the other may be connected ‘by conduit with any riods of high pressure operation may rbe per suitable source of liquid. formed in a minimum of time. A further object When the pump section A is in operation, with is to provide a pump capable of quickly delivering the shaft I4 turning in a clockwise direction as the liquid necessary for performing an operation 25 seen in Fig. 4, the »gears I8 and I9 function un which requires high liquid presures, at least dur ing some periods of the operation, while at the same time keeping to a minimum the power re quired to actuate the pump. » der well-known principles to draw liquid from the passage 23 and pass it between the gears and on through the passage 26. Passage 26 communicates with passage 2l lead Another object is to provide effective means for 30 ing rearwardly in the body IU (shown in dotted cutting off the delivery of liquid delivered by the lines in Fig. 2), and passage 2'I communicates pump under high pressure while the pump re with the passage 28 which leads upwardly to mains in operation. It is desired that such cut the opening 29 at the top of the body I0 (see Fig. oiî means shall be easy to operate and maintain 3) and that it shall not be subject to wear through 35 For controlling the pressure developed by the erosion when in operation. low pressure pumping section A, there is provided A further object is to provide a pump unit a pressure regulating apparatus 30. This appa which is compact and has all moving parts read ratus includes the plunger 3I carried in the cy ily accessible. Other objects and advantages will be apparent 40 lindrical cavity 32 of the body IU, which cavity l communicates at its bottom with passage 23. as the specification proceeds. The upward movement of the plunger 3| is re An embodiment of the invention is illustrated sisted b-y the spring 33, the upper end of which in the accompanying drawings, in which bears against the centering piece 34, which in Fig. 1 is a perspective view of a pump fully turn bears against the bottom of adjusting screw assembled; Fig. 2 is a plan sectional view taken 45 35 carried in the nut member 35. A cap 31 car as indicated at line 2-2 of Fig. l; Fig. 3 is an ele ried on the nut member serves to enclose the vational sectional View taken as indicated at line screw 35. l ` 3--3 of Fig, 2; Fig. Il is an elevational sectional A passage or conduit 38 leads from cavity 32 view taken as indicated at line 4-4 of Fig. 2; and to an opening in the top of body I0, which open Fig. 5 is an elevational sectional View taken as 50 ing may be connected by suitable conduit with indicated at line 5-5 of Fig. 2. a low pressure liquid receiver which may be the As illustrated, the structure includes a pufmp same as the liquid source with which the inlet body l e to which is secured the iront bearing cap passage 231s connected. As seen moreclearly I I and the rear bearing cap I2. Screws I3 serve at Fig. 4 of the drawings,V when the `plunger 3l to fasten these caps tight against the pump body. 55 is moved upwardly against the spring 33 to bring 2,407,923 . 3 4 Y, The conduit $2 connects the- outlet of the high the mouth of the conduit 38 into communication with the lower part of the cavity 32, a part of the liquid delivered by the pump section A may be by-passed through the conduit 38 and led through other suitable conduit back to the liquid source. The apparatus 30 may be adjusted by turning pressure section to the pipe 86 which forms the pump outlet and leads to the particular appliance receiving the hydraulic power. The conduit 'l2 containing the valve 'i3 is connected to the pipe 88 which, as before explained, leads back to the source of liquid supply in the housing 82. rThe inlet conduit 9| has its one end connected with the inlet opening 2li and its other end connected with the source of liquid supply. The conduit 9@ connects the passage 38 with pipe 88 leading the adjusting screw 35 to permit greater or lesser pressure to be developed by the pump section A as may be desired. When the screw is turned to a lower position, this requires a greater liquid pres sure on the bottom of the plunger 3| to raise the back to the liquid source. plunger suñiciently to allow liquid to be ley-passed through the passage 38. Communicating with the passage 23 is a side conduit Bil which leads to thevalve cavity :il (see Fig. 3). In this cavity is the valve ¿l2 including a ball 43 pressed by spring 44, the top of which is held by the plug 65. The valve arrangement is such as to permit liquid to pass from the pas'- . sage @il into the valve cavity, but to prevent the ‘ When the improved pump is started in opera tion, the valves 'l2 and 89 are closed, and the ro tation cf shaft Iii powered by motor Il serves to actuate both the low pressure section and the high pressure section. The rotation of gears I8 and lâ of the low pressure section serves to draw liquid from the source through the conduit 9i and passage 23, and to pass liquid under pressure through the passage 26. Frompassage 26, the back ñow ci liquid from the valve cavity into the passages 49 and 28. The valve cavity 45 com municates through the passage llt with thel cyl índer 5i! of the high pressure pump section B. g :The highpressure pump section B;.(see Figs, 3 liquidv passes >consecutively through passages 2l and Zâ, and is led through pipe 83 from which it passes through valves 84 and 85' to the outlet of the pump. The construction of this low Ypres and 51)¿is._ driven through the rotation of the . shaft,I i4 on which is mounted the eccentric El. sure section permits the delivery of liquid at a relatively rapid rate. However, when the pressure builds up substantiallyrat the pump outlet, liquid is no longer delivered directly from the low pres extend-_ing verticallyy above, the eccentric 5I is lined 30 sure section tothe pump outlet, A.as above de with a lbushing 56 and apiston ,53 is mounted Pressure at the outlet-of the low pressure sec for reCíproCal movement within the cylinder. The tion above a predetermined amount causes the base ofk piston 5.3 rests on the bearing 54 of the plunger 3l to rise against the spring 33 to permit eccentric El and is adapted to be moved in re a small amount ofv liquid to be by-passe‘d back ciprocal motion through actuation by rotation of to the' liquid source, and when a high pressure` is the eccentric. 'Access to the cylinder is provided TheV shaft is journaled inthe bearings le and 52V on-'eacbside of. theeccentric 5l. The cylinder 55 scribed. ' ' , by the plugged opening 51 at the top, and a called forv at the pump outlet so that no liquid plugged opening 5B, allows access to the eccentric. Anvout'let from the high pressure section is plunger rises still further so that a major portion can'be delivered directly through pipe 83, the provided by the passage 6i] leading from the . or" the liquid passed by the gears is ley-passed back passage d6 (see Fig. 2). Passage 6U leads through the valve structure 6I to the conduit 62> which may lead to the pump outlet. The valve struc turel Ell) includes a cavity 53 in which is located to the source. In this way, the pressure of the liquid at the outlet of the low pressure section is maintained at a substantially constant level, ir respective of how mu'ch `of the ' liquid passed therethrough is delivered to the pump outlet. At the same time that liquid is being delivered such as to _prevent iiow of liquid from the pump» to the pump outlet through operation of the low outlet back into the high pressure pump section. pressure section to build up the pressure at the A passage ‘I0 leads from the top of cylinder 55 pump outlet, the high pressure section will also and connects through the valve structure 'il with a conduit 'l2 which may lead through needle valve 50 have been Vin. operation, and rotation of the ec centric ‘äl will have produced reciprocation‘of the 'i3 (Fig. l) to a low pressure liquid receiver, suit piston 53. The retraction or downward move ably the liquid source from which liquid is drawn ment of' piston 5.3y will permit liquid tb pass into the inlet passage 23 of the low pressure sec through the' valveI ft2, impelled‘by the pressure tion. The opening of the valve 'H3 serves to permit flow of liquid through passage 'lll and conduit 'l2 55 developed by the low pressure section, and the following advancement or upward movement of to relieve the pressure in the outlet of the high the .piston will force the liquid Awhich has entered pressure section and stop delivery of liquid un through valve ¿i2 out through the passage 6€), der pressure though the reciprocating apparatus valve 6i and conduit 62 to the pump outlet. of this section continue to operate. The pump body Hl, with'the caps il and l2 60 However, until the pressure atthe pump> outlet has built up, the liquid delivered through the attached, may be mounted on the base 80, as conduit e2 from the high pressure section will shown in Fig. 1, and set on top of a housing 82 be small in comparison to the volume of liquid which may contain a receptacle holding a supply delivered thro-ugh the pipe 83 from the >low pres of oil, or other liquid. rI‘he motor l1 is arranged ` ' with its drive shaft in drive connection with the 65 sure section. - When the pumpfoutlet pressure is high and shaft I4. As shown in Fig. 1, the pipe S3 connects the low pressure discharge opening 29 with valves ful-l power is needed, the low pressure section, as bei-ore» stated, ceases to> deliver liquid to the pump Bâ and 85, which in turn connect with conduits outlet, and at this point the operation of the high S6 forming the outlet of the pump. In this par@ ticular set-up, a gauge 87 is provided for indi 70 pressure sectionbecomes of importance. The liq uid under the relatively .low pressure developed eating the pressure developed by the low pressure by the low pressure section passes through the section. ` valve ¿i2 and out by way of valve 6l and~ conduit The pipe Se provides a passage controlled by 62to the pump outlet impelled by the advance y the valve $9 for the return of liquid ‘back to the the ball B4 and spring 65, the arrangement being` source for reuse.V f f . .. i ’ stroke of therecíprocating piston. , Y .Y 5 9,407,929 6 Constructed as it is, the improved pump is able liquid' from said main outlet back to said recipro to deliver at a rapid rate during periods when high power is not required, and when high power is required is able to deliver under high pressure. cating pumping apparatus, a low pressure pump ing section including a rotary gear pumping ap paratus, pressure regulating means for maintain ing the pressure of _ liquid at the output of said This makes the pump extremely versatile, and it may be'actuated With a relatively small motor. For example, a pump of this construction pow ered by a 1/2 H. P. electric motor may develop a pressure of about 3,000 pounds per square inch. An important feature of the improved pump is that the high pressure section is arranged in the low pressure section at a substantially constant level, a conduit system connecting the output of said lovv pressure section with the output‘of said pump and connecting also the >output of said low pressure section with the inlet of said htigh pres sure section, a valve preventing flow of liquid from said main outlet back to said low pressure section, a valve preventing now of liquid back from said high pressure section to said low pres sure section, and means for driving both of said liquid flow circuit in series with the low pressure section. In this Way, pressure is vmaintained on the piston as it moves in its downward or reverse stroke, and the objectionable pulsations common in high pressure systems heretofore used are pumping sections. eliminated. By the improved construction, the _ 3. A pumping unit having a main outlet and comprising a high pressure pumping section with its outlet connected to said main outlet, a valvé preventing the flow of liquid from said main out let back to the outlet of said pumping section, and means for stopping the delivery of fluid under pressure to said main outlet While said pumping movement of the piston is smooth and regular, and the usual vibration caused by reversal of pressure on the piston at the change of the stroke is avoided. It is not necessary to use special oils or other special liquid in the improved pump, and ordi nary motor oil may be used. Cooling of the oil section is in operation comprising a conduit con ' usually required on other high pressure systems 25 necting the outlet of said pumping section to a is not here essential. The means provided in the improved construc tion for stopping now of oil under high pressure is advantageous in that the usual valve in the high pressure line is eliminated. A needle valve 30 low pressure area, a valve for preventing back ñovv of liquid from said low pressure area to the outlet of said pumping section, said last men tioned Valve being adapted to prevent free ñow is subject to considerable wear since the liquid passing through causes erosion. In the improved of liquid from said outlet to said low pressure area, and a valve selectively operable to open and close the passage in said conduit for controlling the passage of liquid through said conduit. structure, the pressure is relieved the moment liquid starts to pass through the valve '13, and erosive Wear is substantially avoided. comprising a high pressure pumping section in cluding a reciprocating pumping apparatus the in a high pressure line is a source of trouble and In the foregoing description, a-single embodi ment of the invention has been described in great detail. It must be understood that this detailed description has been given for purposes of ex planation only, and that the invention may be practiced in many modified forms, and many 4. A pumping unit having a main outlet and . outlet of which is connected to said main outlet and including valve means for preventing iiow of liquid from said main outlet back to said re ciprocating apparatus, means for stopping ñoW of liquid from said reciprocating apparatus to said main outlet, said means including a conduit changes may be made without departing from the spirit of the invention. In the foregoing explanation and in the claims, the terms “high pressure” and “low pressure” are pumping apparatus outlet, and a valve selectively used in a relative sense to describe the pressures ~ operable to open and close the passage in said developed by the one pumping section With rela tion to those developed by the other pumping section, and not for the purpose of designating any particular range of pressures. through the conduit, a low pressure pumping sec I claim: l. A pumping unit having a main outlet and comprising a high and low pressure section eachl having an outlet communicating with said main outlet, said low pressure section having its outlet connected also with the inlet of said highpres sure section and being adapted to deliver liquid to said main outlet at a relatively fast rate so . long as the pressure at said main outlet does not exceed a predetermined pressure, said low pres sure section being also adapted to deliver liquid to said high pressure section when the pressure of said main outlet is in excess of said predeter mined amount, a shaft for driving both of said pumping sections, a valve preventing backflow of liquid from said main outlet to said high pres sure section, and a valve preventing backñow of liquid from the inlet of said high pressure section to said loW pressure section. 2. A pumping unit having a main outlet and comprising a high pressure pumping section in cluding a reciprocating pumping apparatus the outlet of Which is connected to said main outlet and including valve means for preventing llow of connecting the outlet of said reciprocating pump ing apparatus to a low pressure area, a valve pre venting backflow of liquid from said area to said conduit for controlling the passage of liquid tion including a rotary gear pumping apparatus, a conduit system connecting the outlet of said rotary gear pumping apparatus to said main out let and also to the inlet of said reciprocating pumping apparatus, a valve preventing iiow of liquid from said main outlet back to said rotary gear pumping apparatus, a valve preventing flow of liquid from said reciprocating pumping appa ratus back to said rotary gear pumping appara tus, and means for preventing the rise of pressure at the output of said low pressure pumping sec tion beyond a predetermined amount when the fioW of liquid through said conduit system to said main outlet diminishes. 5. .A pumping unit having a main outlet, com prising a high pressure pumping section includ ing a reciprocating pumping apparatus the out let of Which is connected to said main outlet and including valve means for preventing flow of liq uid from said main outlet back to said reciprocat ing apparatus, means for stopping flow of liquid from said reciprocating apparatus to said main outlet, said means including a conduit connect ing the outlet of said reciprocating apparatus to a low pressure area, a valve preventing backiiow 75 of liquid from said area to said pumping appa 9,407,952?? outlet, a Valve seleetively operable to .open and elose the passage in saidl conduit for `eontrol line the passage of liquid through the eondnit, low pressure pumping apparatus, a conduit sys teni oonneeting the .outlet of said low pressure pumping apparatus vto the inlet of said recipro cating pumping apparatus, and a Valve prevent ing flow of liquid from said reciprocating pump ing apparatus back to said low pressure _pumping apparatus. 6, A pumping unit having a main outlet and comprising pumping means >for maintaining a supply of liquid at a substantially constant low pressure,> a reciprocating pumping section hav ing its inlet connected to theoutlet of said pump’ ing means and having its outlet connected to said main outlet,y said pumping section being eiïective for delivering liquid to said main outlet atl rela tively high pressure, a, rotary drive shaft con nested with said pumping means Yand adapted to drive the same, and a kcam on said shaft for driving said reciprocating pumping section upon rotation Vof said shaft. 7. A pumping unit as set ,forth in claim 6 wherein said driving shaft includes a single shaft extending into both said pumping means and said reciprocating pumping section. ' GEORGE E. GALL.