Hydraulic ram
United States Patent Nakane 1 Apr. 29, 1975 1 HYDRAULIC RAM [56] References Cited [75] Inventor: Yasuji Nakane. Yokohama. Japan UNITED STATES PATENTS 73 A 8 I T B Lt 1 265.991 10/1882 Swank et a1. 137/625.38 I ss&#39;gnee hm nd d Tolio Japm 373 46l 11 /1887 Kees 15/407 [22] Filed: Oct. 15, 1973 1.806.270 /1931 Thompson... /407 1.854.518 4/1932 Little 137/5l6l5 1211 APPI- bio-14068152 2,757.685 8/1956 Fritsch l37/5l6.15 3.425774 2/1969 Conn 134/166 C Foreign Application Priority Data K Prinmrv E.\&#39;aminer--Henry Artis M 22. 1973 .l&#39; 48-606 3 d} dpdn 0 Attorney, Agent, or Firm-Donald D. Mon  
 [52] US. Cl 4/255; 15/406; 134/166 C;  
 137/516.15: 251/340; 222/5; 222/518; [57] ABSTRACT 141/191 141/327; 401/187; 401/190 This invention relates to hydraulic rams for use in [51 llll. Cl E03C1 11/00 clearing blocked pipes, drains and other Conduits and [58] Field of Search 4/255; 15/405, 406. 407;  
 of the kind in which a sudden application of gas pressure is employed to impart a shock against the blockage.  
 6 Claims, 4 Drawing Figures J &#39;iIIIIIflIIIIIIIIIIIIIIl/ HYDRAULIC RAM Heretofore, in conventional hydraulic rams as described in US. Pat. No. 3,426,774, pressure gas is conducted to a nozzle through a check valve, and opening said check valve by a trigger or pushing pin, to apply said pressure gas to the blocked conduit, pipe or other portion. However, said conventional hydraulic ram is a complicated construction due to said check valve, so that it is costly. Moreover, it is necessary to exert a strong force to open said check valve in opposition to said gas pressure.  
  Therefore, an object of the present invention is to provide a hydraulic ram of simple and inexpensive construction without employing a check valve.  
  Another object of the present invention is to provide a hydraulic ram easily operable by a relatively weak force and capable of employing high pressure gas for effectively clearing blocked pipes, etc.  
  Another object and feature of the present invention will be apparent from the following description with reference to the accompanying drawings in which:  
  FIG. 1 is a section through the ram of an embodiment of the present invention;  
  FIGS. 2a and 2b are a section of attachment means showing two examples; and  
 FIG. 3 is a section of joint pipe.  
  A shaft 2 is inserted slidably through a closed cylinder or pressure chamber 1, as shown in FIG. 1. A cap 3 is screwed to said cylinder 1 and is hermetically sealed to it by O-ring 4. Said shaft 2 consists of a front section a and a rear section b, and they are connected by pin 5 each to the other. The front section a and rear section b are inserted into said cap 3 and cylinder 1 respectively, and sealed by O-ring 6 and 7 (*second and first seals, respectively). Washer 8 is fixed to front section a at a projected part extending beyond cap 3. Compressed spring 9 is inserted between said washer 8 and cap 3 to bias said cylinder 1 rearwardly (to the right in FIG. 1). Stop 10 is fixed to the inner part of said front section a. Key 11 engages shaft 2 to prevent its rotation.  
  Sleeve 15 closed at one end, is screwed to the rear end of said rear section b shaft 2. Gas bomb 16 is inserted into said sleeve 15. Sleeve 15 and its threads are sometimes referred to as means to mount the gas bomb. Rear section b of shaft 2 has a piercing pipe 17 for breaking the mouth of bomb 16 and releasing the gas contained in the bomb. The pipe 17 communicates the pressure chamber la of cylinder 1 through bore b1 extending axially of said rear section b, and bore b2 extending radially of said rear section b. Rubber valve 18 is provided at the outlet of said bore b2. The right hand end of the shaft is sometimes referred to as its first end, and the left hand end, the other end&#34;.  
  Front section a of shaft 2 an axially-extending bore a1 and a radially-extending bore a2. Bore a2 opens at the peripheral surface of front section a of short 2 in front of stop 10 (i.e., to the left thereof in FIG. 1), so that said bores 01 and a2 communicate with pressure chamber 10 (sometimes called a cavity) when said cylinder 1 advances sufficiently to the left in FIG. 1 relative to shaft 2. The cavity extends around the shaft, and receives gas under pressure to be discharged to clear a blockage. Bores a1 and bl are sometimes respectively called second conduit and first conduit, respectively. Said bore a1 opens to the front end of front section a of shaft 2 so that it forms nozzle 03. The  
 opening of bore a2 on the periphery of the shaft is sometimes called a valving aperature.  
  Attachments 20 and 21, shown in FIG. 2, are to mount on said nozzle a3. The outer surface of said attachments 20, 21 conforms to the inlet of a pipe, conduit, or drain which is blocked and is to be cleared by a burst of gas from this ram.  
  Rear periphery of cylinder 1 includes a thread 23 to engage a matching internal thread pipe 22 has a handle 24 extending transversely across its axis.  
  In use, gasbomb 16 is inserted into the sleeve 15, and the sleeve 15 is screwed on cylinder 1 by its thread 23. The mouth of said bomb 16 is ruptured by the pipe 17, and pressure gas is introduced into pressure chamber of cylinder 1. Then, joint pipe 22 is connected to said cylinder 1 through its thread 23, and attachment 20 or 21 is mounted on said nozzle a3 and engages the inlet of pipe to be vented.  
  Then handle 24 is pushed forward (toward Nozzle W3), and said cylinder 1 moves forward against the force of spring 9. When said bore a2 of from section a of shaft 2 communicates to the pressure chamber of cylinder 1, pressure gas flows through bores a2 and a1, and exist through nozzle a3, parting a shock against blockage, and clearing the pipe, conduit, etc.  
  In the present invention, the construction of apparatus is simple because it does not employ a check valve, and gas pressure is balanced in the axial direction. This invention is not to be limited by the emobdiment shown in the drawings and described in the description, which is given by way of example and not of limitation, but only in accordance with the scope of the appended claims.  
 I claim:  
  1. A ram for releasing gas under pressure to clear a clogged conduit, comprising: an axially extending central shaft; a peripheral cylinder surrounding said shaft, said shaft projecting at both of its ends from said cylinder, said cylinder forming a cavity around said shaft for the reception of gas under pressure; means on a first end of said shaft to mount a gas bomb, including piercing means to pierce the gas bomb and release its contents, said shaft including a first conduit extending from said piercing means to said cavity and second conduit means extending from the other end of the shaft to a valving aperture on the peripheral wall thereof; a first seal making a fluid-tight sliding seal between the cylinder and the shaft, and located between the cavity and the said first end; a second seal making a fluid-tight sliding seal between the cylinder and the shaft and located between the cavity and the other end of the shaft and also between the valving aperture and the cavity when the shaft is in a first axial position whereby to isolate the second conduit from the cavity in that position, the shaft and the cylinder being relatively slidable so the valving aperture can communicate with the cavity in a second axial position.  
  2. A ram according to claim 1 in which spring means opposed between the shaft and the cylinder bias the shaft toward said first position.  
  3. A ram according to claim 1 in which the means to mount the gas bomb comprises a sleeve threadedly attachable to the shaft.  
  4. A ram according to claim 1 in which a joint member comprises a tube adapted to surround and project beyond the gas bomb and bear against the cylinder to provide handle means for shifting the cylinder relative 6. A ram according to claim 5 in which the means to to the shaft&#39; mount the gas bomb comprises a sleeve threadedly at- 5. A ram according to claim 4 in which spring means opposed between the shaft and the cylinder bias the shaft toward said first position.  
 tachable to the shaft.  
 PATENT NO.  
 DATED INVENTOR(S) UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION 3,879,771 April 29, 1975 YASUJI NAKANE It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 Col, Col. Col. Col. Col. Col. Col. Col. Col. Col. Col. Col.  
 Col.  
 [SEAL] line 29,  
 Arrest:  
 RUTH  
 Arresting Officer &#34;ring&#34; should read--ringsbefore &#34;shaft&#34; insert --of-- &#34;a&#34; should be italicized after &#34;2&#34; insert --has-- &#34;short&#34; should read --shaft cancel &#34;respectively&#34; &#34;aperature&#34; should read -apertureafter &#34;thread&#34; insert --on a-- after &#34;22&#34; insert Pipe 22-- &#34;Nozzle W3&#34; should read --nozzle a3-- &#34;exist&#34; should read --exists-- after &#34;direction.&#34; insert --It does not exert any resistance to operation. Only spring 9 must be overcome. Therefore this ram is easily operable by a relatively weak force to release high pressure gas for effective clearing of blocked pipes and the &#34;This&#34; begins a new paragraph Signed and Sealed this.  
 fourth Day Of November I 975 C. MASON C. MARSHALL DANN Commissioner oflatenls and Trademarks