Scissor lift with offset pins

A lift device, comprising:

• a base;
• a platform configured to support an operator;
• and
• a scissor assembly coupling the base to the platform, the scissor assembly including a plurality of scissor layers and an actuator configured to extend and retract the scissor layers, wherein each scissor layer includes:
• an inner arm having an upper end defining a first end axis and a lower end defining a second end axis;
• and
• an outer arm having an upper end defining a third end axis and a lower end defining a fourth end axis, wherein the inner arm is pivotally coupled to the outer arm such that the outer arm and the inner arm rotate relative to one another about a middle axis;
• wherein the upper end of the inner arm, the lower end of the inner arm, the upper end of the outer arm, and the lower end of the outer arm are each pivotally coupled to at least one of the base, the platform, or another one of the scissor layers about the first end axis, the second end axis, the third end axis, and the fourth end axis, respectively;
• wherein an end axis center point is defined for each scissor layer at an intersection between (a) a first straight line that extends from the first end axis to the second end axis and (b) a second straight line that extends from the third end axis to the fourth end axis;
• wherein a middle pin offset distance is defined for each scissor layer between the end axis center point and the middle axis, wherein the middle pin offset distance is positive when the end axis center point is above the middle axis and negative when the end axis center point is below the middle axis;
• and
• wherein at least two of the scissor layers have middle pin offset distances that are not equal to zero, wherein the middle pin offset distance of at least one of the scissor layers is equal to zero, and wherein the sum of all of the middle pin offset distances is equal to zero.

A lift device, comprising:

• a base;
• a platform configured to support an operator;
• and
• a scissor assembly coupling the base to the platform, the scissor assembly including a plurality of scissor layers and an actuator configured to extend and retract the scissor layers, wherein each scissor layer includes:
• an inner arm having an upper end defining a first end axis and a lower end defining a second end axis;
• and
• an outer arm having an upper end defining a third end axis and a lower end defining a fourth end axis, wherein the inner arm is pivotally coupled to the outer arm such that the outer arm and the inner arm rotate relative to one another about a middle axis;
• wherein the upper end of the inner arm, the lower end of the inner arm, the upper end of the outer arm, and the lower end of the outer arm are each pivotally coupled to at least one of the base, the platform, or another one of the scissor layers about the first end axis, the second end axis, the third end axis, and the fourth end axis, respectively;
• wherein an end axis center point is defined for each scissor layer at an intersection between (a) a first straight line that extends from the first end axis to the second end axis and (b) a second straight line that extends from the third end axis to the fourth end axis;
• wherein a middle pin offset distance is defined for each scissor layer between the end axis center point and the middle axis, wherein the middle pin offset distance is positive when the end axis center point is above the middle axis and negative when the end axis center point is below the middle axis;
• wherein at least two of the scissor layers have middle pin offset distances that are not equal to zero, and wherein the sum of all of the middle pin offset distances is equal to zero;
• and
• wherein the middle pin offset distances of two of the scissor layers have equal magnitudes but are offset in opposite directions.

A lift device, comprising:

• a base;
• a platform configured to support an operator;
• and
• a scissor assembly coupling the base to the platform, the scissor assembly including a plurality of scissor layers and an actuator configured to extend and retract the scissor layers, wherein each scissor layer includes:
• an inner arm having an upper end defining a first end axis and a lower end defining a second end axis;
• and
• an outer arm having an upper end defining a third end axis and a lower end defining a fourth end axis, wherein the inner arm is pivotally coupled to the outer arm such that the outer arm and the inner arm rotate relative to one another about a middle axis;
• wherein the upper end of the inner arm, the lower end of the inner arm, the upper end of the outer arm, and the lower end of the outer arm are each pivotally coupled to at least one of the base, the platform, or another one of the scissor layers about the first end axis, the second end axis, the third end axis, and the fourth end axis, respectively;
• wherein an end axis center point is defined for each scissor layer at an intersection between (a) a first straight line that extends from the first end axis to the second end axis and (b) a second straight line that extends from the third end axis to the fourth end axis;
• wherein a middle pin offset distance is defined for each scissor layer between the end axis center point and the middle axis, wherein the middle pin offset distance is positive when the end axis center point is above the middle axis and negative when the end axis center point is below the middle axis;
• wherein at least two of the scissor layers have middle pin offset distances that are not equal to zero, and wherein the sum of all of the middle pin offset distances is equal to zero;
• and
• wherein a first distance is defined between the first end axis and the second end axis of each scissor layer, wherein a second distance is defined between the third end axis and the fourth end axis of each scissor layer, wherein all of the first distances are equal, and wherein all of the second distances are equal.

A lift device, comprising:

• a base;
• a platform configured to support an operator;
• a plurality of scissor sections coupling the base to the platform, wherein a first scissor section and a second scissor section of the plurality of scissor sections each include:
• a first scissor arm;
• a second scissor arm;
• a first bearing member coupled to the first scissor arm and defining a first pin aperture;
• and
• a first pin coupled to the second scissor arm and extending into the first pin aperture, wherein the first pin pivotally couples the first scissor arm and the second scissor arm, wherein the first scissor arm has a top surface and a bottom surface, and wherein the first pin aperture is not positioned between the top surface and the bottom surface;
• and
• an actuator coupled to at least one of the scissor sections, wherein the actuator is configured to extend and retract the scissor sections to move the platform between a fully raised position and a fully lowered position relative to the base,
• wherein, in the first scissor section, the first pin aperture is positioned entirely above the top surface of the first scissor arm, and wherein, in the second scissor section, the first pin aperture is positioned entirely below the bottom surface of the first scissor arm.