| 摘要 |
An apparatus including a top plate, a right spacing member, a left spacing member, left and right sides plate having a length and a width, wherein the length of each of the left side plate and the right side plate is substantially greater than the width of each of the left side plate and the right side plate. The apparatus may further include first, and second wheels connected to the left side plate so that the first and second wheels can rotate about first and second axes which are substantially parallel to the width of the left side plate; and third and fourth wheels connected to the right side plate so that the third and fourth wheels can rotate about third and fourth axes which are substantially parallel to the width of the right side plate. |
| 主权项 |
1. An apparatus comprising:
a frame comprising: a top plate; a right spacing member; a left spacing member; a left side plate having a length and a width, wherein the length of the left side plate is substantially greater than the width of the left side plate; a right side plate having a length and a width, wherein the length of the right side plate is substantially greater than the width of the right side plate; wherein the top surface of the top plate is the uppermost surface of the frame; wherein the top plate does not extend laterally beyond the spacing members in a direction away from the longitudinal center line of the apparatus; wherein the left and right side plates do not extend laterally beyond the spacing members in a direction toward the longitudinal center line of the apparatus; a first wheel connected to the left side plate so that the first wheel can rotate about a first axis which is substantially parallel to the width of the left side plate; a second wheel connected to the left side plate so that the second wheel can rotate about a second axis which is substantially parallel to the width of the left side plate; a third wheel connected to the right side plate so that the third wheel can rotate about a third axis which is substantially parallel to the width of the right side plate; a fourth wheel connected to the right side plate so that the fourth wheel can rotate about a fourth axis which is substantially parallel to the width of the right side plate; wherein the top plate is connected to the left side plate by the left spacing member, so that the top plate is spaced apart from the left side plate; wherein the top plate is connected to the right side plate by the right spacing member, so that the top plate is spaced apart from the right side plate; wherein the left side plate includes a left side flat surface portion between the first wheel and the second wheel, which is greater in length than the diameter of either the first wheel or the second wheel, and wherein the first wheel and the second wheel rotate on the first axis and the second axis, respectively, in a plane which is perpendicular to the left side flat surface portion; wherein the right side plate includes a right side flat surface portion between the third wheel and the fourth wheel, which is greater in length than the diameter of either the third wheel or the fourth wheel, and wherein the third wheel and the fourth wheel rotate on the third axis and the fourth axis, respectively, in a plane which is perpendicular to the right side flat surface portion; wherein the first wheel, the second wheel, the third wheel, and the fourth wheel are configured so that they can be simultaneously placed in contact with a ground surface, so that each of the first, second, third, and fourth wheels can simultaneously roll on the ground surface; wherein when the first wheel, the second wheel, the third wheel, and the fourth wheel are simultaneously placed in contact with the ground surface, so that each of the first, second, third, and fourth wheels can simultaneously roll on the ground surface, the top plate lies substantially parallel to the ground surface and completely above the first, second, third, and fourth wheels; wherein the apparatus has a front and a rear, and wherein the first and third wheels are in the front of the apparatus and the second and fourth wheels are in the rear of the apparatus; wherein there is a distance between the first wheel at the front of the apparatus and the second wheel at the rear of the apparatus, and wherein the top plate spans a length of at least the distance between the first wheel and the second wheel; and wherein the top plate spans a width from a first end to a second end, wherein the first end is about the same distance from the first and the second wheels as the second end is from the third and fourth wheels. |
