Patent Application
20100242207
The present invention is primarily directed to the field of central vacuum systems and more particularly, to an improved end fitting having a spring contact plate for providing more consistent electrical contact between an end fitting on a hose used in a central vacuum system and the respective wall inlet.
While movable vacuum cleaners make up the vast majority of vacuum systems in homes and businesses, there has recently been a significant increase in the use of central vacuum cleaning systems. Movable or portable vacuum cleaners are plugged into an electric outlet and or self-contained system for picking up dust, dirt and debris. Provided there is a long enough cord, the portable vacuum can cover most areas in a home or other building without too much difficulty.
The primary advantage of a central vacuum system is that the user does not have to carry a heavy unit from room to room or up and down stairs. This is particularly advantageous for people who are very concerned about cleaning but have difficulty with the weight of the portable systems. Many times, these people find it more difficult to maneuver the movable vacuum cleaners to various locations in the house, such as up and down stairs or tight spaces, as they are using it. Thus, the central vacuum systems where just the hose is carried, have become more popular.
A building's central vacuum system is provided with a plurality of inlets at various locations throughout the structure. The number and placement of the inlets plays a direct role in the ease of use of a central vacuum system. The more inlets there are for removing dust, dirt and debris, the easier it is for a user to fully clean the entire area. As hose lengths are finite there is a real need for inlets to be placed conveniently throughout the house in many locations. To operate a central vacuum system, a vacuum hose is plugged into the inlet. In many systems besides a venting hose that extends from the inlet to the vacuum motor, there are also electrical conductors that extend from the inlet to the system motor. The electrical conductors permit the user to switch the system on and off at the inlet or, if desired, at the end fitting that is at the end of the hose opposite the inlet. This permits the user to turn the system on and off when the hose is being held by the user without having to return to the wall outlet or other on/off switch. Since the system only has a hose extending from the inlet all the user has to carry or drag along is the vacuum hose and not a canister or other device. The central vacuum system has a central power unit that is situated usually in an out of the way place in the building. For a home it can be, for example, in a basement, in a garage or elsewhere where it is out of the way but yet convenient to empty. The central power unit provides suction to the hose and a receptacle for the dust, dirt and debris picked up by the system. The power unit is connected via hosing or tubing to wall inlet valves positioned at a variety of locations throughout the building. The tubing can be run through the walls, through a basement, attic, cold air returns, etc. In some systems, there is a separate switch that starts the vacuum system when activated. In other systems the insertion of the hose into the wall outlet can trigger operation. In still other systems, the system operates by plugging a hose and a power brush into the wall inlet. The power button is located on the handle on most systems. The system carries the dirt, dust and debris out of the room through the in wall tubing to the main power unit where it is deposited in a canister or bag for disposal.
Many current central vacuum systems utilize a Type A wall valve. The type A wall valve is a dual purpose wall valve with a high voltage (HV)/low voltage (LV). The Type A wall valve is defined by UL1017. While UL1017 sets standards for these HV/LV valves, there exists a multitude of LV wall valves that are not described in any standard since UL is only concerned with HV safety. This lack of LV standardization driven by an agency or industry group is the crux of the problem as there is no uniformity in the connectors.
The UL1017 defined wall valves provide an air connection, line voltage power and low voltage on/off signaling connections. More specifically, the air connection provides an air path for airborne dust and debris obtained from cleaning to be transmitted to a receptacle for removal. The line-voltage power connection (often called high-voltage power and hereafter abbreviated “HV”) is switched line-level AC power for powering a motorized power head and other power accessories on the end of the hose. The low-voltage signaling connection (hereafter abbreviated “LV”) is a switched low-voltage source (typically 24V or less, AC or DC) that is used to remotely switch the main vacuum unit on and off for use by a user. While the air path and HV power connections are reasonably well-defined by UL1017 (but not fully defined, it is important to note), the LV signaling connections are not defined at all. As a result, there are a wide variety of low-voltage connection implementations and orientations in commercially available wall inlet valves. Ideally, a single wall end fitting would be able to fit all Type A wall valves and function properly, but due to omissions and ambiguities in the standards, this is not always possible in practice.
Current implementations of the LV connection utilize semi-cylindrical metal tabs on the sides of the air connection portion of the fitting. The challenge to this implementation is that the mating implementations in the Type A wall valves vary greatly; there are fixed and spring loaded pins of varying diameters and positions with differing degrees of flexibility and range of motion. Therefore, the size, shape, geometry and diameter of the LV contacts on the hose wall end fitting are critical in making a reliable connection. For example, in the current production wall fitting two thicknesses of LV contacts must be used in order to fit an acceptable percentage of the installed base of wall valves. This increases the expense in manufacturing the hose end fittings.
The present invention provides an improved low voltage signaling connection for hoses. More particularly, the present invention is directed to a spring-loaded LV contact plate that can accommodate a broader range of wall-valve LV connection implementations. The semi-cylindrical shape used previously has been eliminated. The present invention is provided with a semi-conical shape with integral spring legs.
More specifically, the present invention is directed to an improved end fitting for a hose. The end fitting can be on either end of the hose. In a preferred embodiment, the same end fitting can be inserted into a wall inlet or into the power head or other accessories used by the vacuum system. The end fitting has one end that is secured to an end of a hose. The other end of the end fitting is adapted to be inserted into the opening in a wall inlet or the opening in a power head or other accessory. The end of the fitting that is adapted to be received by the inlet preferably has a generally cylindrical member extending from the fitting. The cylindrical member has a first end and a second end. One of the ends is secured to the housing of the end fitting. The cylindrical member is in the form of a hollow tube open at each end. The free end of the cylindrical member is preferably provided with a smaller cross section with the opposite end secured to the housing. The outer surface of the cylindrical member is preferably tapered so that the end can be easily inserted into the wall inlet. The cylindrical member has on its outer surface a spring clip contact plate that provides a low voltage electrical connection with the central vacuum system.
The electrical connection is provided by one or more preferably two spring contact plates. At least a portion of the outer surface of each spring contact plate is raised above the outer surface of the cylindrical member. The spring contact plates have a top surface, a bottom surface and are generally curved to conform generally in shape to the outer surface of the cylindrical member. The plates have four edges and have the edge generally at right angles to each other. Extending from the first edge to the second edge on each side of the spring contact plate are first and second side edges. These side edges follow the general curved contour of the spring contact plate. The spring contact plate has a first side edge which is the edge closest to the end tip of the housing of the end fitting and a second side edge which is the side closest to the main body of the housing or end fitting.
At the first side edge of the spring contact plate there is a sidewall extending from the top surface of the plate inwardly toward the center point of the opening in the cylindrical member. The side wall is generally at an angle to the top surface of the contact plate and extends for a short distance. In one embodiment the side wall is generally perpendicular to the top surface of the contact plate. There is a lip extending outwardly from the sidewall. The lip is generally parallel to the top surface and perpendicular to the sidewall. The lip may have one or more serrations or tabs extending outwardly of the lip extending from the sidewall. The lip preferably has a plurality of tabs extending outwardly from the lip the tabs have a top edge and a pair of side edges extending from the top edge to the edge of the lip. The side edges of the tabs are preferably angled to facilitate mounting.
On the opposite edge of the contact spring there are a plurality of fingers extending from the top surface. These fingers are extending outwardly of the edge of the spring contact plate and are generally in the same plane as the top and bottom surfaces of the spring contact plate, i.e. there is preferably a continuous surface from the top and bottom surface of the spring contact plate to the fingers.
One group of fingers are generally triangular in configuration with a tip and two side edges extending toward said second edge. This first group of fingers extend from the side edge of the spring contact place over the outside surface of the cylindrical member and a portion of the end fitting where the cylindrical member is connected to the end fitting. The second type of finger extends a short distance from the edge and contacts a corresponding raised pin on the housing. This second type of finger has a raised angular tip that extends upwardly of the top surface of the contact spring. The pin that is on the housing prevents axial movement of the spring when the spring is inserted into a Type A wall inlet or a powered head. The configuration of the pin and the respective tab on the contact spring plate causes the spring plate to flex outwardly in a radial direction with minimum axial displacement. This arrangement and the arrangement of the other fingers on the spring contact plate provide good electrical contact with the LV electrical contacts in the Type A inlet.
As seen in
The end 11 of the core 10 opposite the end secured to the hose has a generally cylindrical member 15 having a generally circular cross section. The cylindrical member is hollow to permit air to pass through the cylindrical member. The cylindrical member 15 is preferably shaped so that it is slightly smaller in cross section at the free end 11 than at the end 16 secured to the core 10. The cylindrical member is adapted to be inserted into the orifice in a Type A wall valve. The tapering towards the free end facilitates this. The first end 16 is secured to the housing and the second end 11 is the free end. A portion of the cylindrical member or neck 17 has a diameter less than the remaining portion of the cylindrical member. This recessed portion receives the spring contact plates 14. The entire cylindrical body 15 can be tapered or just the end or tip portion from the end 11 to the neck 17 can be tapered to facilitate insertion into the wall valve configuration. The cylindrical member 15 has a recessed portion or a neck 17 and an end region 18 that extends from the neck to the tip 11 of the body 15. The neck 17 can be of a smaller diameter than the end region 18. This provides room for the contact plate 14 which provides a low voltage connection to the wall valve. The low voltage connection operates, for example, the on/off switch of the system.
Around the neck is at least one contact plate 14. Preferably there are two or more contact plates that are in separated by an insulating member to prevent contact with each other (See
The contact plates are generally in the form of a ring around the neck of the cylindrical member between the end 11 of the cylindrical member 15 and the remainder of the housing 53. The components of the end fitting i.e., the LV contact plates, hose, HV connector, housing etc are mounted to the core. The core positions the contact plates while the housing prevents them from coming out of position after assembly. The contact plate has an outer surface 19 and an inner surface 20. The inner surface conforms generally to the shape of the outer surface of the neck. The outer surface conforms generally to the inner surface of the wall outlet so that an electrical contact may be made between the contact plate and the inner surface of the wall outlet. The contact plate has a first edge 21 and a second edge 22. The contact plate preferably has two generally straight edges 21 and 22 and two curved edges 23 and 24. The generally straight edges 21 and 22 are positioned on the neck generally parallel to the direction of air travel through the core 10. One straight edge of the contact plate may be secured to the straight edge of a second contact plate to form a contact plate arrangement around the neck of the end. There are preferably two or more contact plate portions that are secured together. Depending on the number of contact plates that form the sleeve that surrounds the neck of the end, the first edge 21 of the first contact plate may be secured to the second end 22 of the second contact plate. The second end 22 of the first contact plate can then be secured to the first end 21 of the second contact plate. The same end to end arrangement can be used for additional contact plates that may make up the ring.
Extending from the first edge to the second edge on each side of the spring contact plate are first and second side edges 23 and 24. These edges follow the general curved contour of the spring contact plate. The spring contact plate has a first side edge 23 which is the edge closest to the end tip 11 of the core 10 of the end fitting and a second side edge 24 which is the side closest to the main body of the housing. The spring contact plate has an outer surface 19 and an inner surface 20 as noted above. At the first side edge 23 of the spring contact plate there is a sidewall 25 extending from the top surface 19 of the plate inwardly toward the center point of the opening in the cylindrical member 15. The side wall 25 is generally angled or may be perpendicular to the top surface of the contact plate and extends for a short distance. There is a lip 26 extending outwardly from the sidewall. The lip 26 is generally parallel to the top surface and perpendicular to the sidewall. The lip may extend for a distance as desired based on the mounting arrangement on the cylindrical member as discussed below. The lip may have one or more serrations or tabs 27 extending outwardly of the lip extending from the sidewall. The lip preferably has a plurality of tabs extending outwardly from the lip the tabs have a top edge 28 and a pair of side edges 29 and 30 extending from the top edge to the edge of the lip 26. The side edges of the tabs are preferably angled to facilitate mounting.
On the opposite edge 24 of the contact spring there are a plurality of fingers 31 extending from the top surface. These fingers are extending outwardly of the edge 24 of the spring contact plate and are generally in the same plane as the top and bottom 19 and 20 surfaces of the spring contact plate. One group of fingers 31 are generally triangular in configuration with a tip 32 and two side edges 33 and 34 extending toward said second edge. This first group of fingers 31 extend from the side edge of the spring contact place over the outside surface of the cylindrical member and a portion of the end fitting where the cylindrical member is connected to the end fitting. The second type of finger 35 extends a short distance from the edge and contacts a corresponding raised pin 36 on the housing. This finger 35 has a raised angular tip 37 that extends upwardly of the top surface of the contact spring. The pin 36 that is on the housing prevents axial movement of the spring when the spring is inserted into a Type A wall inlet or a powered head. The configuration of the pin and the respective tab on the contact spring plate causes the spring plate to flex outwardly in a radial direction with minimum axial displacement. This arrangement and the arrangement of the other fingers on the spring contact plate provide good electrical contact with the LV electrical contacts in the Type A inlet. The third type of finger 38 extends outwardly from the top surface. This finger has a base 39 attached to a side edge, a first side edge 40 and a second side edge 41 ending in a tip 42. As seen in the Figure, the tab has a first section 43 that is generally parallel to or at a slight angle to the top surface of the contact spring. There is a mid region 44 that is generally perpendicular or angled to the first section and a tip region 45. This third tab follows the contour of the outer surface of the core 10. The tab may be provided with an orifice 46 on its surface that passes through the tab. The third type of finger 38 is a tab designed to match with a “FastOn” type electrical connector. There are a number of other electrical connection solutions suitable for the low volt implementation (solder, welding, etc.).
The LV spring contact plate can flex to contract to a range of diameters to fit a broader range of wall valve LV connection implementations.
