Protrusive structure apparatus

1. An apparatus configured to provide a retractable protrusive structure, the apparatus comprising:

a base comprising a first surface;

a plurality of guides disposed on the first surface, the plurality of guides radially spaced about an axis of rotation, the axis of rotation being substantially perpendicular to the first surface, the plurality of guides including a first guide and a second guide, a first end of the first guide and a first end of the second guide being positioned closer to the axis of rotation relative to a second end of the first guide and a second end of the second guide;

a plurality of members including a first member and a second member, individual ones of the plurality of members corresponding to individual ones of the plurality of guides, an outward end of the first member being configured to translate via the first guide from the first end of the first guide to the second end of the first guide, and an inward end of the first member being configured to couple with an inward end of the second member;

wherein:

a protruded configuration is effectuated from a retracted configuration by translating the outward end of the first member from the second end of the first guide to the first end of the first guide, and translating an outward end of the second member from the second end of the second guide to the first end of the second guide, causing the apparatus to protrude from the retracted configuration to the protruded configuration; and

the retracted configuration comprises the first member and the second member lying flat against the first surface.

2. The apparatus of claim 1 , wherein individual ones of the plurality of guides have an arcuate shape.

3. The apparatus of claim 1 , wherein the inward end of the first member is fixed to the inward end of the second member such that the first member and the second member form a singular member.

4. The apparatus of claim 1 , further comprising a coupler positioned proximate to the axis of rotation, wherein the inward end of the first member and the inward end of the second member are coupled by the coupler such that the members extend outwardly from the coupler toward the guides.

5. The apparatus of claim 4 , wherein the plurality of members are fixedly coupled to the coupler.

6. The apparatus of claim 4 , wherein the plurality of members are removably coupled to the coupler.

7. The apparatus of claim 4 , further comprising a post disposed proximate to the axis of rotation, the post being configured such that the coupler translates along the post responsive to the apparatus changing between the retracted configuration and the protruded configuration.

8. The apparatus of claim 1 , wherein the first member and the second member form an arch in the protruded configuration in a plane substantially perpendicular to the first surface, the arch being open toward the first surface.

9. The apparatus of claim 1 , wherein, the first member forms a first arch and the second member forms a second arch in the protruded configuration, in a plane substantially perpendicular to the first surface, the first arch and the second arch being open away from the first surface.

10. The apparatus of claim 1 , wherein the plurality of members have default positions and are formed from a resilient material such that:

the first member deflects from a default position against the first surface responsive to a load in a first direction, the load in the first direction acting to push the outward end and the inward end of the first member closer together; and

the first member returns to the default position responsive to cessation of the load in the first direction.

11. The apparatus of claim 1 , further comprising a retracted-configuration locking mechanism and a protruded-configuration locking mechanism, the retracted-configuration locking mechanism configured to releasably lock the apparatus in the retracted configuration, the protruded-configuration locking mechanism configured to releasably lock the apparatus in the in protruded configuration.

12. The apparatus of claim 11 , wherein the retracted-configuration locking mechanism comprises a notch proximate to the second end of the first guide, and wherein the protruded configuration locking mechanism comprises a notch proximate to the first end of the first guide.

13. The apparatus of claim 1 , wherein individual ones of the plurality of members comprise one or more of straight beams, curved beams, or trusses.

14. The apparatus of claim 1 , wherein individual ones of the plurality of members are flexible.

15. The apparatus of claim 14 , wherein individual ones of the plurality of members have a specific elasticity profile, and wherein the elasticity profiles of the plurality of members are adjustable such that the apparatus may be configured for damping.

16. The apparatus of claim 1 , wherein individual ones of the plurality of members are rigid.

17. The apparatus of claim 1 , further comprising a material coupled to the plurality of members, the material configured to form a substantially domed super-structure over the protruded configuration.

18. The apparatus of claim 1 , wherein the protruded configuration includes a maximum protrusion distance, and wherein the maximum protrusion distance is adjustable.

19. The apparatus of claim 1 , further comprising a flexible material disposed over the plurality of members such that the first member and second member are positioned between the material and the first surface of the base, wherein the material is configured to form a substantially dome-shaped structure when the apparatus is in a protruded configuration.

20. The apparatus of claim 19 , wherein the material comprises a resilient sheet.

21. The apparatus of claim 19 , wherein the base is affixed to or integrated with a housing body of a handheld personal exercise device.

22. The apparatus of claim 21 , wherein the dome-shaped structure is configured to receive a compressive force exerted by a user during personal exercise.