A piezo-electric air spring, comprising an air spring and a piezo-electric sensor for generating electrical charges to determine the weight of a semi-trailer.

Provided is a cushion capable of accurately measuring and displaying a weight of a user sitting on the cushion, and convenient to store, use, and carry. The cushion includes a flexible sheet constituting a bottom part; a flexible seat having an integrated rectangular space part formed on the flexible sheet; a pressure transfer medium injected into the space part of the flexible seat; a pressure transfer medium injected into the space part of the flexible seat; and a scale for sensing pressure applied to the pressure transfer medium by an external pressure applied to the flexible seat and displaying the pressure as a weight, in which the scale includes a load cell, a base member, a control unit, a first display unit and a second display unit.

Provided are an apparatus for estimating vehicle mass using tire air pressure and a method thereof, the apparatus for estimating the vehicle mass including: an air pressure determining unit; a speed measuring unit; a data storing unit; an error calculating unit; and a mass calculating unit.

A precision detection device for a force standard machine includes a first hydraulic cylinder, a pipeline and a force loading device. A liquid medium is disposed in, the first hydraulic cylinder, and a liquid level area of the liquid medium is a known Value. The pipeline is a hollow tubular structure, and a first end of the pipeline is communicated with the liquid medium in the first hydraulic cylinder. The force loading device acts on the liquid medium, in the first hydraulic cylinder to produce a pressure increment or a pressure intensity increment on the, liquid medium. A force value comparison machine and a precision detection method for a force standard machine are also provided.

A hitch ball assembly for a trailer hitch. The hitch ball assembly includes a clam-shaped body having a plurality of hinged segments operable between an open position and a closed position. Each of the plurality of hinged segments includes a concave inner surface that collectively form a ball shaped-cavity configured to enclose a smaller-diameter hitch ball. Each of the hinged segments further includes an outer surface that collectively form a larger-diameter hitch ball configured to engage a trailer tongue when the hinged segments are operated to the closed position.

A method for determining the wheel load or axle load of an air-sprung vehicle by measuring the internal pressure of the air spring, wherein the wheel load or axle load is determined using a pressure curve which represents the relationship between a bearing force acting on the air spring and the internal pressure of the air spring, characterized in that starting from a wheel load or axle load determined by pressure measurement, using an original pressure curve of an air spring which has been newly brought into operation, further pressure measurements are carried out using pressure curves which, in comparison with the original pressure curve, show a change reflecting the aging of the air spring.

A weight measuring hitch ball assembly is described. The assembly can include a hitch ball having a ball and a lower portion. The assembly can also include a body portion defining a hitch ball opening that slidably receives the lower portion of the hitch ball. The assembly can further include a load measurement device operably associated with the body portion and the hitch ball to determine a magnitude of a force acting on the hitch ball. Additionally, the assembly can include a retention coupling operable with the hitch ball and the body portion to secure the hitch ball to the body portion. The retention coupling can have a retention protrusion and a retention wall defining at least a portion of a retention opening operable to receive at least a portion of the retention protrusion therein. With the retention protrusion extending into the retention opening, the retention wall can provide a mechanical barrier to the retention protrusion that prevents removal of the hitch ball from the hitch ball opening. The retention opening can be configured to facilitate slidable movement of the hitch ball within the hitch ball opening sufficient to determine the magnitude of the force acting on the hitch ball.

A hitch ball assembly for a trailer hitch. The hitch ball assembly includes a clam-shaped body having a plurality of hinged segments operable between an open position and a closed position. Each of the plurality of hinged segments includes a concave inner surface that collectively form a ball shaped-cavity configured to enclose a smaller-diameter hitch ball. Each of the hinged segments further includes an outer surface that collectively form a larger-diameter hitch ball configured to engage a trailer tongue when the hinged segments are operated to the closed position.

A ball mount for measuring tongue weight of a trailer is disclosed. The ball mount can include a ball portion having a hitch ball configured to couple with a tongue of a trailer. The ball mount can also include a hitch portion for interfacing with a hitch receiver associated with a vehicle. In addition, the ball mount can include a load measurement device associated with the ball portion to determine a magnitude of a downward force on the hitch ball. The load measurement device can include a reservoir having a fluid and a piston disposed therein, and a pressure sensor in fluid communication with the reservoir. The hitch ball can be configured to exert a force on the piston, thereby affecting a pressure of the fluid in response to the downward force on the hitch ball.

A ball assembly for attachment to a ball mount is described. The ball assembly can include a ball post that is securable to a ball mount. A hitch ball is slidably coupled to the ball post at a ball end of the ball post. A load gauge is disposed at the gauge end of the ball post. A load transfer element is operably associated with both the hitch ball and the load gauge so as to cause a load measurement to display on the load gauge based upon a load applied to the hitch ball.