Grease gun

Abstract

A grease gun includes a housing, a motor positioned within the housing, a pump assembly coupled to and driven by the motor, and a chamber supported by the housing in fluid communication with the pump assembly. The chamber is configured to store a liquid. The grease gun also includes an outlet in fluid communication with the chamber and a measurement system operable to measure an amount of liquid being dispensed through the outlet. The measurement system monitors a change in current of the motor over a cycle of the pump assembly, compares the change in current to a predetermined value, and, if the change in current is greater than the predetermined value, increases a pump cycle counter to indicate that liquid was dispensed.

1 . A grease gun comprising:
 a housing;   a motor positioned within the housing;   a pump assembly coupled to and driven by the motor;   a first actuator supported by the housing and electrically coupled to the motor, the first actuator being actuatable to energize the motor;   a chamber supported by the housing and in fluid communication with the pump assembly, the chamber being configured to store a liquid;   an outlet in fluid communication with the chamber; and   a measurement system electrically coupled to the motor and including a second actuator, the second actuator being actuatable to input a number of pump strokes to be performed, the measurement system being operable to increase a pump cycle counter each time the pump assembly performs a pump stroke and dispenses liquid, and to automatically stop the motor when the pump cycle counter equals the inputted number of pump strokes to be performed.   
     
     
         2 . The grease gun of  claim 1 , wherein the measurement system is configured to automatically stop the motor while the first trigger is actuated. 
     
     
         3 . The grease gun of  claim 1 , wherein the second actuator includes a dial, the dial being rotatable to input the number of pump strokes to be performed. 
     
     
         4 . The grease gun of  claim 3 , wherein at least a portion of the dial extends outwardly through an opening in the housing. 
     
     
         5 . The grease gun of  claim 3 , wherein the dial includes a plurality of values on an outer surface of the dial, each value corresponding to a different number of pump strokes to be performed. 
     
     
         6 . The grease gun of  claim 1 , wherein the first actuator includes a trigger. 
     
     
         7 . The grease gun of  claim 1 , wherein the measurement system is operable to monitor a change in current of the motor over a cycle of the pump assembly, to compare the change in current to a predetermined value, and, if the change in current is greater than the predetermined value, to increase the pump cycle counter to indicate that liquid was dispensed. 
     
     
         8 . The grease gun of  claim 7 , wherein the measurement system is operable to not increase the pump cycle counter if the change in current is less than a predetermined value. 
     
     
         9 . The grease gun of  claim 7 , wherein the predetermined value is approximately 0.5 amps. 
     
     
         10 . The grease gun of  claim 1 , wherein the chamber includes a barrel assembly configured to receive a lubricant cartridge. 
     
     
         11 . The grease gun of  claim 1 , further comprising an output hose coupled to the housing and in fluid communication with the chamber, the output house including the outlet. 
     
     
         12 . A method of operating a grease gun, the grease gun including a motor, a pump assembly coupled to the motor, an actuator electrically coupled to the motor, a chamber in fluid communication with the pump assembly and configured to store a liquid, an outlet in fluid communication with the chamber, and a measurement system electrically coupled to the motor, the method comprising:
 inputting a number of pump strokes to be performed into the measurement system;   actuating the actuator to energize the motor;   driving the pump assembly with the motor while the actuator is actuated;   increasing a pump cycle counter of the measurement system each time the pump assembly performs a pump stroke and dispenses liquid; and   automatically stopping the motor when the pump cycle counter equals the inputted number of pump strokes to be performed.   
     
     
         13 . The method of  claim 12 , wherein automatically stopping the motor includes automatically stopping the motor while the actuator is actuated. 
     
     
         14 . The method of  claim 12 , wherein the actuator is a first actuator, wherein the measurement system includes a second actuator, and wherein inputting the number of pump strokes to be performed includes actuating the second actuator to input the number of pump strokes to be performed. 
     
     
         15 . The method of  claim 14 , wherein the second actuator includes a dial, and wherein actuating the second actuator includes rotating the dial to input the number of pump strokes to be performed. 
     
     
         16 . The method of  claim 12 , wherein the actuator includes a trigger, and wherein actuating the actuator includes depressing the trigger to energize the motor. 
     
     
         17 . The method of  claim 12 , further comprising monitoring a change in current of the motor over a cycle of the pump assembly, comparing the change in current of the motor to a predetermined value, and, if the change in current is greater than the predetermined value, increasing the pump cycle counter to indicate that liquid was dispensed. 
     
     
         18 . The method of  claim 17 , further comprising holding the pump cycle counter constant if the change in current is less than the predetermined value. 
     
     
         19 . The method of  claim 17 , wherein the predetermined value is approximately 0.5 amps. 
     
     
         20 . The method of  claim 12 , wherein inputting the number of pump strokes to be performed includes inputting one of a volume of fluid to be dispensed and a weight of fluid to be dispensed, and wherein the method further comprises converting the one of the volume of fluid to be dispensed and the weight of fluid to be dispensed to the number of pump strokes to be performed.