Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed:

Field of the invention:
[0001] The present disclosure relates to a hand primer.

Background of the invention:
[0002] According to a prior art 201641006410 discloses a hand primer for a fuel feed pump. This invention discloses a hand primer for a fuel feed pump. The hand primer comprises a hollow primer-body with a first reduction-joint at its first end for coupling said primer-body with said fuel feed pump. A handle is attached to a second end of said primer-body. The primer-body and first reduction-joint are made as a single piece.

Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawings,
[0004] Fig. 1 illustrates a fuel injection system with fuel pump fit with a hand primer, according to an embodiment of the present invention;
[0005] Fig. 2 illustrates two side cross-section views of the hand primer, according to an embodiment of the present invention, and
[0006] Fig. 3 illustrates different states of the hand primer, according to an embodiment of the present invention.

Detailed description of the embodiments:
[0007] Fig. 1 illustrates a fuel injection system with fuel pump fit with a hand primer, according to an embodiment of the present invention. The fuel injection system 100 comprises a reservoir 108 storing fuel such as gasoline, diesel, or flex-fuel, blended fuel, etc. The fuel is pumped by a low pressure pump, which is also fixed with a hand primer 110. The low pressure pump pressurizes the fuel and then sends to high pressure pump through a filter. The high pressure pump then delivers the fuel to an injector 102 at a specific pressure. The fuel is combusted inside the engine 104 and delivers the output. The flow direction of fuel from the reservoir 108 to the injector 102 is shown by the arrows in the connecting lines. A battery 106 is also provided which powers the necessary electronic and electrical components. The fuel injection system 100 is explained for clarity with emphasis only on the hand primer 110, whereas the other parts or components are not explained to avoid complexity.

[0008] Further, in Fig. 1, the mounting of the hand primer 110 is shown in an enlarged view 120. The housing/mounting block 116 of the low pressure pump comprises a bore with internal threads. The hand primer 110 is screwed 114 to the internal threads and firmly fixed.

[0009] Fig. 2 illustrates two side cross-section views of the hand primer, according to an embodiment of the present invention. A first view 200 shows a first cross section view of the hand primer 110. A second view 230 shows a second cross-section view of the hand primer 110 for better clarity. The first view 200 and the second view 230 are cross-section view at 90 degrees shift of the hand primer 110. A cap 216 is also provided for protecting an end of the second portion 214, through which the hand primer 110 is mounted to the pump or block. The cap 216 is shown in the second view 230. The grooves to which the cap 216 is mounted is visible in first view 200. The hand primer 110 comprises a housing 208 comprising a first portion 222 and a second portion 214. The second portion 214 comprises narrower hollow region than the first portion 222. A neck of the housing 208 defines the first portion 222 and the second portion 214. A plunger 210 positioned inside the first portion 222 of the housing 208 through a first end 206. The plunger 210 comprises a handle 204 for manual operation, characterized in that, the handle 204 and the plunger 210 are integrally formed as a single body. The housing 208 has multiple functions. The housing 208 acts as an interface with supply pump/mounting block, houses plunger 210, provides guide for valve spool, acts as barrel which suction and delivery of fuel, gives rigidity to hand primer 110. The plunger 210 is used to create suction pressure and to deliver the fuel to low pressure circuit/line.

[0010] According to an embodiment of the present invention, the first end 206 of the housing 208 is bent towards the plunger 210 through caulking process. The first end 206 provides an opening for insertion of the plunger 210. The plunger 210 comprises a cavity, and the cavity is closed by a cap 202. The cap 202 is snap-fit to the handle 204 for closing the cavity. The cap 202 provides flexural rigidity to the plunger 210 while priming and also avoids entry of dust and water inside cavity of the plunger 210. Further, a gasket 218, for sealing, is positioned at an interface of handle 204 and the plunger 210. The sealing gasket 218 arrests entry of water and dust in static (when the plunger 210 is screwed inside the housing 208) and dynamic/working condition. The gasket 218 also acts as a positive stopper for plunger 210 while the thread is tightened.

[0011] According to an embodiment of the present invention, the handle 204 and the plunger 210 are made of a first material. The first material is selected from a metal, an alloy, and a plastic. In an embodiment, the plunger 210 and cap 202 are made of Polyamide 66 black unfilled material.

[0012] According to an embodiment of the present invention, the plunger 210 comprises a first section and a second section 224. The second section 224 is narrower than the first section. The remaining part of the plunger 210 apart from the second section 224 is the first section. In other words, a shoulder of the housing 208 defines the first section and the second section 224. The second section 224 is inserted into the second portion 214 of the housing 208. Specifically, the second section 224 is screwed to an internal thread of the second portion 214 of the housing 208.

[0013] According to an embodiment of the present invention, the plunger 210 comprises the cavity for weight reduction. Alternatively, the plunger 210 is a solid/filled body. In accordance to an embodiment, the plunger 210 is made of plastic and the housing 208 is made of steel.

[0014] According to an embodiment of the present invention, a working of the plunger 210 is explained. Consider the Fig. 1, where the hand primer 110 is shown fixed in line of the connecting lines which conveys fuel from the reservoir 108 to the low pressure pump and the high pressure pump. Consider that the engine 104 has not been switched ON for some time and there is high possibility of the air in the connecting lines/conduits. A user unscrews the plunger 210 using the handle 204 by rotating anti-clock wise direction. Once the plunger 210 is unscrewed, the user pulls the plunger 210 out as shown by a position 220 in second view 230 of Fig. 2. By pulling the plunger 210, the user draws in fuel in the space vacated by the plunger 210. The user then pushes the plunger 210 back, which circulates the fuel further towards the low pressure pump through the one-way valve setup as known in the art. The user keeps reciprocating the plunger 210 until a specific number of times, or time and then completes the priming operation.

[0015] Fig. 3 illustrates different states of the hand primer, according to an embodiment of the present invention. In first state 310, the plunger 210 is screwed to the housing 208. In a second state 320, the plunger 210 is unscrewed from the housing 208, and is now ready to be freely movable up and down in the housing 208. In a third state 330, the plunger 210 is shown moved to the free end of the housing 208 to draw fuel in the empty chamber 302 through suction. The plunger 210 is then pushed down to circulate the sucked fuel further into the connecting lines towards the high pressure pump. Further, the plunger 210 comprises a stop 304 to restrict movement out of housing 208 during suction.

[0016] According to an embodiment of the present invention, a method of assembling the hand primer 110 is provided. At first, the housing 208 is formed with internal threads in second portion 214. The plunger 210, which is formed by molding process, is inserted inside the housing 208 and then screwed. Once, inserted, the first end 206 of the housing 208 is bent inwards to hold the plunger 210 firmly using the caulking process. The caulking process comprises bending the edges/periphery of the housing 208 inwards by pressing a roller onto the housing 208. This is done by mounting the housing 208 on to a lathe/ Computer Numerical Control (CNC) turning center, or by using pneumatic/hydraulic crimping machine.

[0017] According to the present invention, the hand primer 110 with plastic plunger 210 and steel housing 208 for priming fuel from reservoir 108 is provided. The hand primer 110 is provided with a lesser number of components for ease in manufacturing with reduced time. The structure of the hand primer 110 is also simple. Further, the material chosen makes the hand primer 110 a light weight product. The hand primer 110 is used to prime fuel from reservoir 108 when the low-pressure line is starved. The hand primer 110 comprises components, viz., cap 202, gasket 218, plunger 210, housing 208, and O-ring 212. The O-ring 212 is housed on plunger 210 and prevents leakage of fuel from oil side to air side of the hand primer 110.

[0018] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.
, Claims:We claim:
1. A hand primer (110), said hand primer (110) comprises:
a housing (208) comprising a first portion (222) and a second portion (214), said second portion (214) comprises narrower hollow region than said first portion (222);
a plunger (210) positioned inside said first portion (222) of said housing (208) through a first end (206), and
said plunger (210) comprising a handle (204) for manual operation, characterized in that,
said handle (204) and said plunger (210) are integrally formed as a single body.

2. The hand primer (110) as claimed in claim 1, wherein said first end (206) is bent towards said plunger (210) through caulking.

3. The hand primer (110) as claimed in claim 1, wherein said plunger (210) comprises a cavity, said cavity is closed by a cap (202).

4. The hand primer (110) as claimed in claim 1, wherein said handle (204) and said plunger (210) are made of a first material.

5. The hand primer (110) as claimed in claim 4, wherein said first material is selected from a metal, an alloy, and a plastic.

6. The hand primer (110) as claimed in claim 1, wherein a gasket (218) is positioned at an interface of handle (204) and said plunger (210).

7. The hand primer (110) as claimed in claim 1, wherein said plunger (210) comprises a first section and a second section (224), wherein said second section (224) is narrower than said first section.

8. The hand primer (110) as claimed in claim 7, wherein said second section (224) is screwed to an internal thread of said second portion (214) of said housing (208).

9. The hand primer (110) as claimed in claim 1, wherein said plunger (210) is made of plastic and said housing (208) is made of steel.

10. The hand primer (110) as claimed in claim 1, wherein said plunger (210) comprises a stop 304 to restrict movement out of said housing (208) during suction.