Combination seat post and air pump for bicycle

1. An air pump comprising:

a hollow post having an inner surface, an upper end and a lower end;

means mounted on the upper end of the post for allowing the post to be gripped;

a tube partially extending into the post through the lower end thereof, said tube having an inner end within the post and an opposite end;

a diaphragm secured to the inner end of the tube and in sliding engagement with the inner surface of the post;

a check valve adjacent to the diaphragm for providing a one-way flow of air through the tube; and

a hose mounted on the opposite end of the tube for connecting the tube to a device to be inflated.

2. An air pump as set forth in claim 1, wherein a plug is secured to the post for closing the upper end of the post, said plug and said diaphragm forming a chamber for air to be compressed when the diaphragm is moved under the influence of the tube toward the plug.

3. An air pump as set forth in claim 2, wherein an O-ring seal is on the plug and in engagement with the inner surface of the post.

4. An air pump as set forth in claim 1, wherein the inner end of the tube has a rigid member coupled thereto, said member having an open and an interior recess provided with a ball defining said check valve, and a spring biasing the ball into closing relationship to the open end of the rigid member.

5. An air pump as set forth in claim 4, wherein a threaded screw has a central air passage therethrough, the screw being threadably coupled to said rigid member and provided with a flange for holding the diaphragm to the rigid member.

6. An air pump as set forth in claim 5, wherein said screw has an inner end and said ball is biased against the inner end of the screw in closing relationship to the air passage therethrough.

7. An air pump as set forth in claim 1, wherein said post has a bearing member at the opposite end thereof, said tube being slidably received in a central hole of the bearing member.

8. An air pump as set forth in claim 1, wherein the tube has a projecting member on the outer end thereof, said projecting member having said hose thereon.

9. An air pump as set forth in claim 8, wherein said projecting member has a lateral air passage with and outer end, said hose having a first fitting threadably coupled to the outer end of the lateral air passage.

10. An air pump as set forth in claim 9, wherein said projecting member has a threaded hole therethrough for threadably receiving the first fitting on the hose to permit the hose to extend longitudinally of the tube and thereby allow the post and tube to extend into the tubular frame part of the bicycle.

11. An air pump as set forth in claim 8, wherein said hose is secured to said projecting member and extends generally parallel with the tube.