Patent Application
20050133636
This invention relates to an improved disc for moving a slide valve used in a fire fighting nozzle.
Valves for use with various kinds of fire apparatus are well known in the art. Such valves are used to direct fire extinguishing fluids, such as water and water-foam combinations, onto fires. Such valves may be, for example, attached to the ends of hoses that are transported by fire pump trucks. Many different kinds of fire fighting nozzles are known in the art. One example of a fire fighting nozzle is shown and described in U.S. Pat. No. 4,589,439 (“the '439 patent”). The '439 patent issued to Robert W. Steingass on May 20, 1986, and was assigned to Task Force Tips Incorporated, the assignee of the present application.
The '439 patent describes a fire fighting nozzle that includes a receiver section and a coaxial, tubular body section. A flow control valve assembly is enclosed within the receiver section and the tubular body section. As may best be seen in
When moved in a forward direction, the tubular sliding valve member is moved into an abutting relationship with the valve seat. This prevents the discharge of fluid from the nozzle. In contrast, when the tubular sliding valve member is moved in a rearward direction, the valve member is moved out of abutting relationship with the valve seat. In this rearward position, an annular opening is formed between the valve member and the valve seat. The fluid can then be discharged through this annular opening.
This forward and rearward movement of the sliding member is initiated by the corresponding forward and rearward movement of a handle. The handle is secured to the receiver section by means of a disc that is contained within a mating bore formed in the receiver section. One such disc is shown in
For example, the Prior Art disc shown in the attached
A handle is used to move the slide valve into and out of engagement with the valve seat. The handle is attached to a disc, and the movement of the handle coincides with rotation of the disc. Friction created by the contact between the drag nubs and the walls of the mating bore is desirable. That friction creates the sensation of a drag on the handle when it is moved in a forward or rearward direction, providing the handle with a sense of heft. Moreover, this drag helps to prevent the inadvertent and unintended movement of that handle. Such inadvertent movement can occur as a result of forces encountered in the rugged conditions of use, and as a result of the water pressures attributable to high water discharge volumes, that are typically encountered during fire fighting.
While such a prior art disc is generally reliable, failures occur in approximately two units annually per thousand units in the field. The failures occur as a result of the structures found in these discs. Specifically, these prior art discs are held in place with a retaining ring, as may also be seen in
Thus, it would be desirable to design a new disc that would overcome the disadvantages of the current, prior art discs. It would also be desirable to design a disc that, when broken or defective, could be readily removed from the receiver section, and be replaced with a new disc.
The invention is an improvement in a disc and a handle for moving a slide valve of a fire fighting nozzle. Together, this disc and handle facilitate the opening and closing of a fire nozzle assembly, for permitting and preventing, respectively, the discharge of fire extinguishing fluids from that nozzle. The improvement of the present invention results from the use of a one-piece disc. The disc has at least one resilient, normally outwardly biased biasing means. Here, the preferred biasing means is one or two generally resilient arms. The improvement of the invention also results from the use of a novel plastic handle with a generally oblong shaped slot.
More particularly, the invention is a one-piece disc for insertion into a mating bore of a hollow member that is a component of the fire fighting nozzle assembly.
The novel disc includes a generally cylindrical disc body. That disc body has a nominal diameter, and a generally smooth perimeter. The disc body also has resilient, normally outwardly biased arms.
When the disc body is positioned outside of the mating bore, a portion of the arms extends beyond the nominal diameter of the disc body. In contrast, when the disc body is positioned within the confines of the mating bore, these resilient arms are biased inwardly by the periphery of the mating bore. The resilient arms are then compressed by the walls of the mating bore. As a result, the resilient arms are substantially contained within the nominal diameter of the disc body.
When the one-piece disc is placed within the mating bore, these resilient arms are compressed. However, their designed-in, normally outward bias results in a tendency of those arms to be biased back in the direction of their original position. As a result, when the one-piece disc is contained within the mating bore, the arms have a natural tendency to push outwardly and press against the peripheral walls of the mating bore. This pressing ensures a secure, frictional fit of the disc body within the mating bore. The disc body is preferably made of a plastic or nylon material, and can include a central orifice into which a threaded fastener may be inserted.
The hollow valve member of the fire fighting nozzle assembly has a plurality of recesses. A plastic handle includes an oblong slot, and that oblong slot contains a ball to engage the recesses. The oblong slot also includes a spring which biases that ball towards those recesses for that engagement. The oblong slot is constructed to permit movement of the ball in a generally upward and downward direction, while restricting movement of the ball in a generally side-to-side direction.
The invention is an improvement in a disc and a handle for moving a slide valve of a fire fighting nozzle.
The nozzle assembly 10 is generally held by the fireman. The nozzle assembly 10 may include grip 11 that can be held by the fireman. This grip 11 extends from the nozzle assembly 10 to allow the fireman to counteract and neutralize the reverse thrust caused by the discharge of large volumes of water from the nozzle assembly 10. As a result, the fire fighter has an easier time handling the nozzle assembly 10, and is better able to direct the fire extinguishing fluids to the desired location.
A handle is used to move the sliding member into and out of engagement with the valve seat. Because the handle is attached to this disc 16, movement of the handle coincides with rotation of the disc 16. Friction created by the contact between the drag nubs 18, 20 and the walls of the mating bore is desirable. That friction creates the sensation of a drag on the handle when it is moved in a forward or rearward direction, providing the handle with a sense of “heft.” Moreover, this drag helps to prevent the inadvertent and unintended movement of that handle. Such inadvertent movement can occur as a result of forces encountered in the rugged conditions of use, and as a result of the water pressures attributable to high water discharge volumes, that are typically encountered during fire fighting.
These shortcomings of these and other prior art discs 16 are overcome by the present invention, which is centered around a disc 30. The construction of the fire fighting nozzle assembly 10 is highly similar to the construction of the assembly shown in U.S. Pat. No. 4,589,439, whose disclosures are incorporated by reference.
As may be seen in
This pair of discs 30 and 40 are intended for insertion, respectively, into one of the two mating bores 42, 44. Mating bore 42 can be seen fully in
One side of disc 30 and disc 40 includes tabs 48 and 50. These tabs 48 and 50 permit the proper insertion of the discs 30, 40 into the bores 42, 44. In order to facilitate retention of discs 30, 40 within the receiver section 86, each disc 30, 40 has at least one resilient, normally outwardly biased biasing means. The biasing means may include one arm, but here preferably includes two arms 34 and 36. These arms 34 and 36 should be compressed in the direction of the arrows shown in
After the discs 30, 40 are secured within the bores 42, 44, those discs 30, 40 may rotate within those bores, subject to certain limits of rotation. Particularly, the discs 30 and 40 may be rotated between the two positions depicted in
In contrast, when the handle 32 is in its rearward position, as shown in
Referring again to
To secure that handle 32, trunnions 60, 62 are inserted through holes 64, 66 in the handle 32, and then through the central orifices 28 of the discs 30, 40. The discs 30, 40 are made of either a plastic or nylon material. As a result, for example, when the trunnion 60 is placed into the central orifice 28 of disc 30 and rotated in a clockwise direction, the rotation of that trunnion 60 forms self-tapped, conjugate resilient threads upon the nylon or plastic peripheral surface 68 of central orifice 28. Continued rotation of the trunnions 60, 62 causes them to engage the internally threaded nuts 56, 58 and in this way firmly secure the handle to the discs 30, 40. The resilient threads effectively prevent the trunnions 60, 62 from loosening up over time thereby obviating the need for a thread locking compound between the trunnions 60, 62 and the threaded nuts 56, 58.
Movement of the handle 32 forward, i.e., towards the discharge end of the nozzle assembly 10, moves the hollow slide valve member 46 into contact with the stationary valve seat 26, and closes the nozzle. When the nozzle 10 is closed, fire extinguishing fluids cannot be discharged. In contrast, movement of the handle 32 rearwards, i.e., away from the discharge end of the nozzle assembly 10, moves the hollow slide valve member 46 away from the stationary valve seat, and opens the nozzle 10. When the nozzle 10 is opened, fire extinguishing fluids may be discharged.
As may best be seen in
One of the improvements of the present invention results largely from the use of a one-piece disc 30. As a result of this improvement, a broken or otherwise damaged disc 30 can be replaced. The disc 30 of the present invention, if corroded, worn, or otherwise damaged, can be replaced. The disc 30 of the present invention also eliminates some of the problems and complications attributable to multi-piece discs, such as the prior art multi-piece disc shown in
As may best be seen in
In the preferred embodiment, the cylindrical disc 30 has a “nominal diameter” of approximately 1.58 inch. For the purposes of this invention, the term “nominal diameter” means the diameter of the disc body when it is outside of the mating bore 42, and exclusive of its generally resilient arms 36 and 38. The “nominal diameter” is shown in the dotted lines that circumscribe the disc body in
The preferred thickness of the cylindrical disc 30 is approximately 0.420 inch. The disc includes a generally smooth perimeter 39.
Discs 30 and 40 are identical. As noted above, disc 30 also has resilient, normally outwardly biased arms 34 and 36. The outwardly biased arms 34 and 36 have a cross section that is relatively thin. As a result, upon the application of force to the arms, at the point and in the direction depicted by the arrows of
Conversely, when that force is released, the arms 34 and 36 spring back, and return to their normal, outwardly biased position of
In contrast, when the disc body 30 is positioned within the confines of the mating bore 42, these resilient arms 34 and 36 contact the periphery of the mating bore 42, and that contact contracts the arms 34 and 36 so that they are biased inwardly. The resilient arms 34 and 36 are then compressed into a position where they are substantially contained within the confines of the nominal diameter of the disc body 30.
In summary, when the one-piece disc 30 is placed within the mating bore 42, these resilient arms 34 and 36 are compressed. However, their designed-in, normally outward bias results in a tendency of those arms 34 and 36 to return to their original position. As a result, when the one-piece disc 30 is contained within the mating bore 42, the arms 34 and 36 have a natural tendency to push outwardly and press against the periphery of the mating bore 42. This pressing ensures a secure, friction fit of the disc body 30 within the mating bore 42. As a result of this friction fit, the typical torque necessary to turn these discs 30, 40 when they are within their mating bores 42, 44 is approximately 19 in-lbs-f.
Referring now to
One of the seven recesses 76 on each side of the receiver section 86 will be engaged by an adjacent ball 78, of two separate ball 78 and spring 80 combinations on each arm of the handle 32. Each of the two ball 78 and spring 80 combinations are captured in one of the two oblong slots 82 and 84 in the plastic handle 32. The spring 80 strongly biases the ball 78 towards the various recesses 76. A ball 78 snaps into a particular recess 76 when it is adjacent or proximate to that recess 76. When the ball 78 is engaged with a particular recess 76, the handle 32 has a greater tendency to remain firmly in its position, even during the difficult conditions encountered during fire fighting.
Another of the improvements of the present invention is the plastic material of its handle. This handle is less expensive, and easier to manufacture, than the prior art metal handles. This novel handle is resilient enough to withstand a severe blow, and yet return substantially to its normal shape, without losing its function. Such severe blows could arise in the event that a fire truck were to drive over the fire fighting nozzle, or if the nozzle were dropped directly onto the pavement by its handle.
Plastic handles will, however, contract and expand to a greater degree than metal handles. As a result, if the slot in the plastic handle were of a conventional circular shape, the expansion or contraction of the circular slot in the plastic handle could result in misalignment between the ball and the recesses. In fact, the extent of the misalignment could be sufficient so as to prevent the engagement of the ball with any of the recesses.
To compensate for the expansion or contraction of this plastic handle, the slot in the present invention is an oblong slot 82, 84. When the plastic handle expands or contracts in an upward or downward direction, i.e., along the axis of the arm of the handle 32, the oblong shape of the slot permits upward or downward movement of the ball 78 within the oblong slot 82 or 84. In this way, the ball 78 can “find” the nearest adjacent recess 76.
As may best be seen in
Although the preferred embodiments herein described are sized to coincide with hollow slide valve member 46 having an internal waterway of 1.5 inches, the invention may be made either larger or smaller. The one piece discs may also be made with only one resilient arm, or with more than two arms provided that they develop adequate friction to retain the position of the handle 32. Alternately, other resilient means such as deformable bumps, or looped shaped structures, could be formed to develop suitable friction. These and other modifications may be made without departing from the true spirit and scope of the invention.
