1. A spindle head structure of a machining device, the spindle head structure having a spindle that is rotatable in A and B axes directions about substantially perpendicular axes, the spindle head structure comprising:
a spindle support adapted to be fixed with the spindle;
an intermediate support connected with the spindle support via two coaxial upper revolute pairs that have a common rotation axis;
a base support connected with the intermediate support via two coaxial lower revolute pairs that have a common rotation axis;
an upper telescopic strut connected between the spindle support and the intermediate support; and
a lower telescopic strut connected between the intermediate support and the base support.
2. The spindle head structure according to claim 1, wherein the upper telescopic strut comprises:
an upper telescopic limb;
a first revolute pair connected between the upper telescopic limb and the spindle support; and
a second revolute pair connected between the upper telescopic limb and the intermediate support; and
the lower telescopic strut comprises:
a lower telescopic limb;
a third revolute pair connected between the lower telescopic limb and the base support; and
a forth revolute pair connected between the lower telescopic limb and the intermediate support.
3. The spindle head structure according to claim 1, wherein the common rotation axis of the upper revolute pairs is substantially perpendicular to the common rotation axis of the coaxial lower revolute pairs.
4. The spindle head structure according to claim 1, wherein the intermediate support is driven by the lower telescopic strut to rotate around the lower revolute pairs relative to the base support, and the spindle support is driven by the upper telescopic strut to rotate around the upper revolute pairs relative to the intermediate support, so that the spindle support is rotatable around X and Y axes of a coordinate system relative to the base support.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An electrical connector comprising:
a base housing;
a housing cover assembled onto the base housing, said housing cover defining an inner wall, first and second preload ridges extending from the inner wall, and an aperture between said first and second preload ridges, wherein each said preload ridge defines a respective first section extending at a first angle relative to the inner wall, and a respective second section adjacent to the first section that extends at a second angle relative to the inner wall, wherein the second angle is different from the first angle; and
a receptacle contact extending into the base housing, said receptacle contact having a pair of contact beams that engage the preload ridges such that the aperture is disposed between the contact beams.
2. The electrical connector of claim 1, wherein the first and second sections cause the contact beams to move apart to preload the contact beams against the preload ridges.
3. The electrical connector of claim 1, wherein said aperture is for receiving a complementary electrical contact into the receptacle contact.
4. The electrical connector of claim 1, wherein the second section is farther from the inner wall than the first section and the second angle is less than the first angle.
5. The electrical connector of claim 1, wherein the contact is a bifurcated dual-beam contact.
6. The electrical connector of claim 1, wherein the contact comprises a pair of single beams.
7. The electrical connector of claim 1, wherein each of the base housing and the cover is molded from an electrically insulating material.
8. The electrical connector of claim 1, wherein the contact is stamped from a sheet of electrically conductive material.
9. The electrical connector of claim 1, wherein the contact is retained in the base housing.
10. The electrical connector of claim 1, wherein the first preload ridge causes a first of the pair of contact beams to move in a first direction as the first preload ridge engages the first contact beam.
11. The electrical connector of claim 10, wherein the second preload ridge causes a second of the pair of contact beams to move in a direction opposite the first direction as the second preload ridge engages the second contact beam.
12. The electrical connector of claim 11, wherein the second contact beam moves in the direction opposite the first direction by a predetermined distance in response to movement of the cover toward the base housing.
13. The electrical connector of claim 11, wherein the first and second sections of the first preload ridge oppose, respectively, the first and second sections of the second preload ridge.
14. The electrical connector of claim 1, further comprising a second receptacle contact extending into the base housing, said second receptacle contact having a contact beam that engages the first preload ridge.
15. The electrical connector of claim 14, further comprising a third receptacle contact extending into the base housing, said third receptacle contact having a contact beam that engages the second preload ridge.
16. An electrical connector comprising:
a base housing;
a receptacle contact extending into the base housing, said receptacle contact having a pair of contact beams, each said contact beam having a lead-in surface for engaging a respective preload ridge defined by a housing cover, said housing cover defining an inner wall from which the preload ridges extend and an aperture between the preload ridges, wherein each said preload ridge defines a first section extending at a first angle relative to the inner wall, and a second section adjacent to the first section that extends at a second angle relative to the inner wall, wherein the second angle is different from the first angle,
wherein each said contact beam is adapted to move by a predetermined distance to preload the contact beam against the preload ridge such that the aperture is disposed between the contact beams.
17. The electrical connector of claim 16, wherein each contact beam is adapted to cam outwardly relative to the aperture in response to motion of the cover toward the base.
18. The electrical connector of claim 16, further comprising a second receptacle contact extending into the base housing, said second receptacle contact having a contact beam that engages at least one of the preload ridges.
19. An electrical connector comprising:
a base housing;
a housing cover assembled onto the base housing; and
an electrical contact inserted into the base housing, said electrical contact having a contact beam with a lead-in surface for engaging a preload ridge defined by the housing cover, said housing cover defining an inner wall from which the preload ridge extends and an aperture proximate the preload ridge, wherein said preload ridge defines a first section extending at a first angle relative to the inner wall, and a second section adjacent to the first section that extends at a second angle relative to the inner wall, wherein the second angle is different from the first angle,
wherein the contact beam is adapted to move a specified distance to preload the contact beam against the preload ridge.
20. The electrical connector of claim 19, wherein the receptacle contact has a second contact beam with a lead-in surface for engaging a second preload ridge defined by the housing cover, said housing cover further defining an aperture disposed between the first and second preload ridges for receiving a complementary electrical contact between the beams of the receptacle contact.